WEBVTT FILE 1 00:00:00.000 --> 00:00:04.920 Good afternoon. I'm Nancy Neal Jones from 2 00:00:02.970 --> 00:00:06.600 the Office of Communications at NASA's 3 00:00:04.920 --> 00:00:10.019 Goddard Space Flight Center in Greenbelt 4 00:00:06.600 --> 00:00:11.969 Maryland. Today we will reveal new and 5 00:00:10.019 --> 00:00:15.360 unexpected discoveries from NASA's 6 00:00:11.969 --> 00:00:19.650 osiris-rex mission telecon graphics are 7 00:00:15.360 --> 00:00:26.519 available right now at HTTPS: forward slash 8 00:00:19.650 --> 00:00:31.289 forward slash SVS dot GSFC dot nasa.gov forward slash 9 00:00:26.519 --> 00:00:35.430 one three one five four I'll repeat HTTPS 10 00:00:31.289 --> 00:00:39.149 colon slash slash SVS for scientific 11 00:00:35.430 --> 00:00:41.969 visualization studio dot GSFC for 12 00:00:39.149 --> 00:00:46.200 Goddard Space Flight Center dot nasa dot gov 13 00:00:41.969 --> 00:00:47.520 slash one three one five four. The Origins 14 00:00:46.200 --> 00:00:51.210 Spectral Interpretation Resource 15 00:00:47.520 --> 00:00:53.820 Identification Security Regolith Explorer 16 00:00:51.210 --> 00:00:57.449 OSIRIS-REx spacecraft launched September 17 00:00:53.820 --> 00:00:57.809 8 2016 and began orbiting the asteroid 18 00:00:57.449 --> 00:01:02.160 Bennu 19 00:00:57.809 --> 00:01:03.600 on December 31st 2018 Since its arrival at 20 00:01:02.160 --> 00:01:05.820 Bennu, the spacecraft has been 21 00:01:03.600 --> 00:01:07.860 investigating the asteroid and searching 22 00:01:05.820 --> 00:01:10.619 for an ideal site for sample collection 23 00:01:07.860 --> 00:01:12.960 to get more insight on the mission and 24 00:01:10.619 --> 00:01:16.439 new science results today's briefing 25 00:01:12.960 --> 00:01:19.380 panelists include Lori Glaze acting 26 00:01:16.439 --> 00:01:23.159 director NASA planetary science division 27 00:01:19.380 --> 00:01:25.500 Washington Dante Lauretta osiris-rex 28 00:01:23.159 --> 00:01:29.460 principal investigator University of 29 00:01:25.500 --> 00:01:32.930 Arizona Tucson Coralie Adam osiris-rex 30 00:01:29.460 --> 00:01:35.340 flight navigator KinetX Inc space 31 00:01:32.930 --> 00:01:38.009 navigation and flight dynamics, Simi 32 00:01:35.340 --> 00:01:40.799 Valley California, Rich Burns 33 00:01:38.009 --> 00:01:42.810 osiris-rex project manager nasa's 34 00:01:40.799 --> 00:01:45.240 goddard space flight center Greenbelt 35 00:01:42.810 --> 00:01:50.399 Maryland we will now begin with Lori 36 00:01:45.240 --> 00:01:53.460 Lori Thank You Nancy NASA's planetary 37 00:01:50.399 --> 00:01:55.920 science program actually runs several 38 00:01:53.460 --> 00:01:58.680 missions that are studying the small 39 00:01:55.920 --> 00:02:00.750 bodies that include asteroids throughout 40 00:01:58.680 --> 00:02:02.250 the solar system and we studied these 41 00:02:00.750 --> 00:02:03.960 asteroids to learn more about the 42 00:02:02.250 --> 00:02:06.719 history of our solar system and our 43 00:02:03.960 --> 00:02:08.160 origins the small bodies mission both 44 00:02:06.719 --> 00:02:10.410 currently operating and plan for the 45 00:02:08.160 --> 00:02:11.720 future it will help the scientists start 46 00:02:10.410 --> 00:02:13.610 to answer questions like 47 00:02:11.720 --> 00:02:16.040 did we come from how did the major 48 00:02:13.610 --> 00:02:19.070 planets form and how to earth get its 49 00:02:16.040 --> 00:02:20.750 water in first three months the of OSIRIS 50 00:02:19.070 --> 00:02:23.540 REx mission is already given us some 51 00:02:20.750 --> 00:02:25.220 amazing science to dig through and I'm 52 00:02:23.540 --> 00:02:26.710 really excited about the results that 53 00:02:25.220 --> 00:02:29.510 are going to be presented here today 54 00:02:26.710 --> 00:02:31.760 there are some expected results some 55 00:02:29.510 --> 00:02:34.400 surprises but this is an incredible team 56 00:02:31.760 --> 00:02:35.960 who can learn and adapt to achieve the 57 00:02:34.400 --> 00:02:37.940 ultimate goal of this mission which is 58 00:02:35.960 --> 00:02:41.060 to collect a sample of the asteroid 59 00:02:37.940 --> 00:02:42.170 Bennu and bring it back to earth and so 60 00:02:41.060 --> 00:02:43.790 with that I want to hand it over to 61 00:02:42.170 --> 00:02:46.190 Dante and jump right into some of these 62 00:02:43.790 --> 00:02:47.780 results. Thank you, Lori. This is an 63 00:02:46.190 --> 00:02:50.930 incredibly exciting time on the 64 00:02:47.780 --> 00:02:54.020 osiris-rex mission my first graphic is 65 00:02:50.930 --> 00:02:56.510 shows a series of high resolution images 66 00:02:54.020 --> 00:02:59.000 that were taken by our poly cam imager 67 00:02:56.510 --> 00:03:01.700 onboard the spacecraft these were images 68 00:02:59.000 --> 00:03:03.890 were acquired on December 2nd of 2018 69 00:03:01.700 --> 00:03:07.070 right as we were finishing the initial 70 00:03:03.890 --> 00:03:08.660 approach to the asteroid and for most of 71 00:03:07.070 --> 00:03:10.250 the following months they provided our 72 00:03:08.660 --> 00:03:12.530 best characterization of the asteroid 73 00:03:10.250 --> 00:03:14.060 surface and they really demonstrate some 74 00:03:12.530 --> 00:03:17.330 of the surprises that this asteroid 75 00:03:14.060 --> 00:03:19.310 presented to us first but unsurprisingly 76 00:03:17.330 --> 00:03:20.900 because we had characterized the 77 00:03:19.310 --> 00:03:24.050 asteroid using ground-based radar 78 00:03:20.900 --> 00:03:26.300 astronomy. Bennu has an expected spinning 79 00:03:24.050 --> 00:03:28.640 top shape it's roughly spherical with an 80 00:03:26.300 --> 00:03:31.010 equatorial Ridge that seems to be 81 00:03:28.640 --> 00:03:32.720 dominated by its rotation and reflective 82 00:03:31.010 --> 00:03:35.030 of the fact that it's a pile of rubble 83 00:03:32.720 --> 00:03:36.860 or gravel and boulders loosely bound 84 00:03:35.030 --> 00:03:39.200 together by their own small gravity 85 00:03:36.860 --> 00:03:41.060 fields however we had expected from 86 00:03:39.200 --> 00:03:43.070 ground-based infrared and radio 87 00:03:41.060 --> 00:03:45.110 astronomy that the surface was 88 00:03:43.070 --> 00:03:47.360 relatively smooth and dominated by 89 00:03:45.110 --> 00:03:49.430 centimeter scale particles which are 90 00:03:47.360 --> 00:03:51.500 optimal for our touch-and-go sample 91 00:03:49.430 --> 00:03:53.060 acquisition mechanism the device that 92 00:03:51.500 --> 00:03:54.920 will ultimately contact the surface of 93 00:03:53.060 --> 00:03:57.739 the asteroid to collect that material in 94 00:03:54.920 --> 00:04:00.350 fact we see a wide range of very large 95 00:03:57.739 --> 00:04:02.959 boulders on the surface our latest count 96 00:04:00.350 --> 00:04:05.600 is over 200 boulders larger than 10 97 00:04:02.959 --> 00:04:07.489 meters in diameter so there's something 98 00:04:05.600 --> 00:04:09.799 interesting going on with the asteroid 99 00:04:07.489 --> 00:04:11.239 geology not only do we see a lot of 100 00:04:09.799 --> 00:04:14.269 boulders but we see that they have a 101 00:04:11.239 --> 00:04:16.519 very wide range of reflectivity or what 102 00:04:14.269 --> 00:04:17.590 we call normal albedo we're seeing 103 00:04:16.519 --> 00:04:19.180 things as dark 104 00:04:17.590 --> 00:04:21.400 only reflecting about three-and-a-half 105 00:04:19.180 --> 00:04:23.889 percent of the length that's shining on 106 00:04:21.400 --> 00:04:25.360 the surface from the Sun up to over 20 107 00:04:23.889 --> 00:04:27.490 percent reflectance and some of the 108 00:04:25.360 --> 00:04:29.320 brightest particles on the surface as a 109 00:04:27.490 --> 00:04:30.880 sample scientist is interested in 110 00:04:29.320 --> 00:04:32.320 getting this material back into our 111 00:04:30.880 --> 00:04:34.240 laboratories here on earth 112 00:04:32.320 --> 00:04:35.889 this is really exciting because it means 113 00:04:34.240 --> 00:04:38.020 that we're going to have a wide range of 114 00:04:35.889 --> 00:04:40.060 materials to study from the dawn of the 115 00:04:38.020 --> 00:04:42.669 solar system to understand the processes 116 00:04:40.060 --> 00:04:44.860 of planet formation and even whether as a 117 00:04:42.669 --> 00:04:47.620 habitable planet with abundant oceans 118 00:04:44.860 --> 00:04:50.050 and origin of life occurring here 119 00:04:47.620 --> 00:04:52.530 however it may pose some challenges for 120 00:04:50.050 --> 00:04:55.060 our navigation systems which rely on 121 00:04:52.530 --> 00:04:56.889 light our instruments which are lasers 122 00:04:55.060 --> 00:04:59.290 that reflect off the surface to give us 123 00:04:56.889 --> 00:05:01.660 a range to the asteroid as well as image 124 00:04:59.290 --> 00:05:04.780 based technologies to guide us into the 125 00:05:01.660 --> 00:05:06.880 potential sample site we show this movie 126 00:05:04.780 --> 00:05:08.680 with the asteroid rotating one of the 127 00:05:06.880 --> 00:05:10.270 most interesting discovery so far is 128 00:05:08.680 --> 00:05:12.280 that since we've been watching the 129 00:05:10.270 --> 00:05:16.389 asteroid astronomically beginning in 130 00:05:12.280 --> 00:05:17.889 1999 up into observations in 2018 we've 131 00:05:16.389 --> 00:05:20.200 seen the rotation rate of Bennu 132 00:05:17.889 --> 00:05:22.000 increasing because of the latest 133 00:05:20.200 --> 00:05:23.950 observations we can attribute this to a 134 00:05:22.000 --> 00:05:26.020 known phenomena called the YORP effect 135 00:05:23.950 --> 00:05:28.120 which is basically how interaction with 136 00:05:26.020 --> 00:05:30.250 sunlight causes the asteroid rotation 137 00:05:28.120 --> 00:05:31.600 rate to increase and probably the most 138 00:05:30.250 --> 00:05:33.610 easily understandable way to 139 00:05:31.600 --> 00:05:36.010 characterize this is what we call the 140 00:05:33.610 --> 00:05:37.720 YORP doubling time in about a million 141 00:05:36.010 --> 00:05:39.460 and a half years we predict that Bennu 142 00:05:37.720 --> 00:05:41.350 will be spinning at twice its current 143 00:05:39.460 --> 00:05:43.870 rate so we definitely see the asteroid 144 00:05:41.350 --> 00:05:45.970 spinning faster and faster we have 145 00:05:43.870 --> 00:05:48.190 learned a lot about the composition of 146 00:05:45.970 --> 00:05:49.840 Bennu from our initial observations and 147 00:05:48.190 --> 00:05:51.370 we have three instruments that allow us 148 00:05:49.840 --> 00:05:53.530 to determine the minerals that are on 149 00:05:51.370 --> 00:05:55.660 its surface we have a thermal emission 150 00:05:53.530 --> 00:05:58.270 spectrometer called OTES which goes out 151 00:05:55.660 --> 00:06:00.250 to very long infrared wavelengths 152 00:05:58.270 --> 00:06:01.900 capturing the heat that's coming off but 153 00:06:00.250 --> 00:06:03.610 also containing information about the 154 00:06:01.900 --> 00:06:05.620 minerals on the surface we have a 155 00:06:03.610 --> 00:06:06.490 visible and near infrared spectrometer 156 00:06:05.620 --> 00:06:08.800 called OVIRS 157 00:06:06.490 --> 00:06:10.690 which characterizes the way sunlight is 158 00:06:08.800 --> 00:06:12.280 reflected off and gives us additional 159 00:06:10.690 --> 00:06:14.289 indications about the minerals on the 160 00:06:12.280 --> 00:06:16.419 surface and then we have our mapping 161 00:06:14.289 --> 00:06:18.940 camera the mass cam which has color 162 00:06:16.419 --> 00:06:21.280 filters that allow us to look at very 163 00:06:18.940 --> 00:06:23.650 broad variations and reflectance 164 00:06:21.280 --> 00:06:24.900 invisible wavelength ranges we have 165 00:06:23.650 --> 00:06:27.570 learned that 166 00:06:24.900 --> 00:06:29.520 Bennu is dominated by water rich clay 167 00:06:27.570 --> 00:06:32.310 minerals or phyllosilicate minerals 168 00:06:29.520 --> 00:06:33.840 which is very exciting and allows us to 169 00:06:32.310 --> 00:06:35.190 really go after the kind of material 170 00:06:33.840 --> 00:06:37.470 from the early solar system that were 171 00:06:35.190 --> 00:06:39.270 interested in but with the MapCam we've 172 00:06:37.470 --> 00:06:41.759 been able to get resolved images and in 173 00:06:39.270 --> 00:06:43.590 the graphic number two I'm showing you 174 00:06:41.759 --> 00:06:45.930 in the middle they're different colors 175 00:06:43.590 --> 00:06:49.620 from our approach phase with the MapCam 176 00:06:45.930 --> 00:06:51.360 and then over there on the right on the 177 00:06:49.620 --> 00:06:53.160 top we've got the ratios of those 178 00:06:51.360 --> 00:06:55.710 different colors and this matches a 179 00:06:53.160 --> 00:06:57.419 known mineral called magnetite or iron 180 00:06:55.710 --> 00:07:00.300 oxide or more familiar on earth 181 00:06:57.419 --> 00:07:02.250 sometimes called a lodestone magnetite 182 00:07:00.300 --> 00:07:04.860 very interesting because it also forms 183 00:07:02.250 --> 00:07:06.690 an aqueous systems often as the result 184 00:07:04.860 --> 00:07:09.090 of very intense action of liquid water 185 00:07:06.690 --> 00:07:11.330 so this confirms Bennu as the ideal 186 00:07:09.090 --> 00:07:14.190 choice for our sample return target on 187 00:07:11.330 --> 00:07:16.590 graphic three I reveal probably the 188 00:07:14.190 --> 00:07:18.449 biggest surprise of the early phases of 189 00:07:16.590 --> 00:07:20.039 the of OSIRIS-REx mission and I would 190 00:07:18.449 --> 00:07:23.070 say one of the biggest surprises of my 191 00:07:20.039 --> 00:07:25.320 scientific career when we got into orbit 192 00:07:23.070 --> 00:07:27.300 our first orbital phase a we actually 193 00:07:25.320 --> 00:07:29.010 were expecting that to be a time for the 194 00:07:27.300 --> 00:07:30.120 science team to kind of process the 195 00:07:29.010 --> 00:07:31.949 information that are already been 196 00:07:30.120 --> 00:07:33.599 acquired and for the flight dynamics 197 00:07:31.949 --> 00:07:36.120 team to learn how to operate the 198 00:07:33.599 --> 00:07:37.949 spacecraft in close proximity to the 199 00:07:36.120 --> 00:07:39.840 asteroid but what I'm showing you here 200 00:07:37.949 --> 00:07:41.699 are actually a composite of two 201 00:07:39.840 --> 00:07:44.010 different images from the navigation 202 00:07:41.699 --> 00:07:45.330 camera there's a short exposure image 203 00:07:44.010 --> 00:07:47.250 which is showing you the asteroid 204 00:07:45.330 --> 00:07:49.710 surface in the lower left and then a 205 00:07:47.250 --> 00:07:51.659 long exposure image and if you look just 206 00:07:49.710 --> 00:07:53.460 off the limb towards the center of the 207 00:07:51.659 --> 00:07:55.650 image you'll see a whole series of 208 00:07:53.460 --> 00:07:58.320 bright pixels those are in fact 209 00:07:55.650 --> 00:08:00.900 particles that are ejecting off the 210 00:07:58.320 --> 00:08:03.300 surface at relatively high velocity so 211 00:08:00.900 --> 00:08:05.820 Bennu is part of a category a very 212 00:08:03.300 --> 00:08:08.550 small group of small bodies in the solar 213 00:08:05.820 --> 00:08:10.979 system called active asteroids we are 214 00:08:08.550 --> 00:08:13.919 seeing bending regularly eject material 215 00:08:10.979 --> 00:08:16.650 into outer space we saw the first event 216 00:08:13.919 --> 00:08:18.539 occur on January 6th of this year and 217 00:08:16.650 --> 00:08:20.909 then we instituted a more rigorous 218 00:08:18.539 --> 00:08:23.430 monitoring process using the navigation 219 00:08:20.909 --> 00:08:25.320 camera starting on January 11th we're 220 00:08:23.430 --> 00:08:27.479 able to continue that high cadence of 221 00:08:25.320 --> 00:08:30.210 observations through February 18th and 222 00:08:27.479 --> 00:08:32.520 we have seen about 11 223 00:08:30.210 --> 00:08:34.229 events over that time period more are 224 00:08:32.520 --> 00:08:36.089 being discovered as we get better at 225 00:08:34.229 --> 00:08:37.890 analyzing and processing the data and 226 00:08:36.089 --> 00:08:40.229 extracting small signals from that 227 00:08:37.890 --> 00:08:42.479 information three of those events have 228 00:08:40.229 --> 00:08:45.060 been substantial with dozens or over a 229 00:08:42.479 --> 00:08:47.910 hundred particles being ejected clearly 230 00:08:45.060 --> 00:08:50.040 into the asteroid environment the 231 00:08:47.910 --> 00:08:52.080 particles seem to be in the size ranges 232 00:08:50.040 --> 00:08:54.990 of centimeters up to tens of centimeters 233 00:08:52.080 --> 00:08:57.270 in diameter and they're moving with 234 00:08:54.990 --> 00:08:59.399 velocities of centimeters per second 235 00:08:57.270 --> 00:09:01.440 which is very slow relative to the 236 00:08:59.399 --> 00:09:04.200 asteroids acceleration and escape 237 00:09:01.440 --> 00:09:05.310 velocity up to several meters per second 238 00:09:04.200 --> 00:09:07.200 which means they're clearly being 239 00:09:05.310 --> 00:09:10.020 ejected into interplanetary space and 240 00:09:07.200 --> 00:09:12.209 away from the asteroid some of those 241 00:09:10.020 --> 00:09:14.880 slow moving particles have been observed 242 00:09:12.209 --> 00:09:16.950 over periods of at least a week and they 243 00:09:14.880 --> 00:09:19.260 appear to be trapped in the asteroids 244 00:09:16.950 --> 00:09:21.450 gravity field and are ending up in orbit 245 00:09:19.260 --> 00:09:24.240 around Bennu so they're creating a zone 246 00:09:21.450 --> 00:09:26.010 set of natural satellites and then some 247 00:09:24.240 --> 00:09:28.649 of them have been observed to fall back 248 00:09:26.010 --> 00:09:31.170 on to the surface basically it looks 249 00:09:28.649 --> 00:09:33.750 like Bennu has a continuous population of 250 00:09:31.170 --> 00:09:35.640 particles raining down on it from 251 00:09:33.750 --> 00:09:38.399 discrete ejection events across its 252 00:09:35.640 --> 00:09:40.529 surface this is incredibly exciting we 253 00:09:38.399 --> 00:09:42.089 don't know the mechanism that is causing 254 00:09:40.529 --> 00:09:44.610 this right now in fact we're still 255 00:09:42.089 --> 00:09:46.709 learning how to process the data analyze 256 00:09:44.610 --> 00:09:49.620 the information and make sense of what's 257 00:09:46.709 --> 00:09:51.630 going on at this asteroid and then in my 258 00:09:49.620 --> 00:09:53.490 final graphic graphic number four it's 259 00:09:51.630 --> 00:09:56.370 just an example of one of our highest 260 00:09:53.490 --> 00:09:59.040 resolution images acquired to date this 261 00:09:56.370 --> 00:10:01.410 is a shot from our PolyCam taken from 262 00:09:59.040 --> 00:10:03.270 the first detailed survey station and it 263 00:10:01.410 --> 00:10:05.640 shows the general rugged nature of the 264 00:10:03.270 --> 00:10:08.370 asteroid surface the field of view here 265 00:10:05.640 --> 00:10:10.020 is 70 meters the good news and the 266 00:10:08.370 --> 00:10:12.630 reason I picked this image to show you 267 00:10:10.020 --> 00:10:15.060 is that at smaller scales we are seeing 268 00:10:12.630 --> 00:10:16.980 patches of fine-grained regolith which 269 00:10:15.060 --> 00:10:18.480 is exactly the kind of material that we 270 00:10:16.980 --> 00:10:20.940 expect to be able to collect with our 271 00:10:18.480 --> 00:10:23.310 TAGSAM sampling device so even though 272 00:10:20.940 --> 00:10:25.770 the surface overall looks bouldery and 273 00:10:23.310 --> 00:10:27.120 rugged and rocky and really not what we 274 00:10:25.770 --> 00:10:30.300 expected from our ground-based astronomy 275 00:10:27.120 --> 00:10:32.730 we are owning in on areas of sample 276 00:10:30.300 --> 00:10:34.529 material and those will be obvious areas 277 00:10:32.730 --> 00:10:37.290 of interest as we move forward with the 278 00:10:34.529 --> 00:10:40.410 mission so I'm going to hand it over to 279 00:10:37.290 --> 00:10:42.480 Coralie Adam Corley is the optical 280 00:10:40.410 --> 00:10:43.290 navigation lead for the mission and she 281 00:10:42.480 --> 00:10:45.750 has been 282 00:10:43.290 --> 00:10:49.350 for a large amount of the success of our 283 00:10:45.750 --> 00:10:52.889 operation so far so Coralie Thank You 284 00:10:49.350 --> 00:10:54.720 Dante I'm moving on my first graphic on 285 00:10:52.889 --> 00:10:56.339 December 31st the navigation team 286 00:10:54.720 --> 00:10:59.339 delivered OSIRIS-REx into a 287 00:10:56.339 --> 00:11:01.050 record orbit around Bennu making Bennu 288 00:10:59.339 --> 00:11:03.509 the smallest planetary body to ever be 289 00:11:01.050 --> 00:11:05.250 orbited by a spacecraft the team 290 00:11:03.509 --> 00:11:07.470 achieved another record for the smallest 291 00:11:05.250 --> 00:11:09.269 orbit around a planetary body which is 292 00:11:07.470 --> 00:11:11.430 an elliptical orbit with the closest 293 00:11:09.269 --> 00:11:15.000 distance falling just under a mile from 294 00:11:11.430 --> 00:11:18.269 the asteroid center giving into this 295 00:11:15.000 --> 00:11:20.430 orbit around such a small asteroid is 296 00:11:18.269 --> 00:11:22.560 really challenging given the fact that 297 00:11:20.430 --> 00:11:24.630 the force of the radiation pressure or 298 00:11:22.560 --> 00:11:26.339 the the sunlight acting on the 299 00:11:24.630 --> 00:11:28.470 spacecraft is on the same order of 300 00:11:26.339 --> 00:11:31.709 magnitude as the gravitational pull from 301 00:11:28.470 --> 00:11:35.730 Bennu on the left-hand side of this 302 00:11:31.709 --> 00:11:37.709 graphic you see the orbit as if you're 303 00:11:35.730 --> 00:11:40.740 looking down from the Sun and on the 304 00:11:37.709 --> 00:11:42.750 right-hand side you see a side view you 305 00:11:40.740 --> 00:11:46.470 can see that the orbit plane is facing 306 00:11:42.750 --> 00:11:48.810 the Sun we call this a frozen orbit 307 00:11:46.470 --> 00:11:50.850 because it uniquely balances forces 308 00:11:48.810 --> 00:11:52.860 between the solar radiation pressure and 309 00:11:50.850 --> 00:11:56.790 gravity so it allows for a more 310 00:11:52.860 --> 00:11:58.500 longer-term stability when we got into 311 00:11:56.790 --> 00:12:00.389 this orbit it was so stable that we 312 00:11:58.500 --> 00:12:03.829 didn't need to do any adjustments during 313 00:12:00.389 --> 00:12:08.040 the scheduled eight weeks in orbit 314 00:12:03.829 --> 00:12:09.690 moving on to slide my slide to the 315 00:12:08.040 --> 00:12:11.430 objective of this initial orbit phase 316 00:12:09.690 --> 00:12:13.139 was to transition to a method of 317 00:12:11.430 --> 00:12:14.699 navigation called landmark tracking 318 00:12:13.139 --> 00:12:16.740 which would improve our navigation 319 00:12:14.699 --> 00:12:19.980 performance from future, for future 320 00:12:16.740 --> 00:12:23.250 mission phases instead of finding the 321 00:12:19.980 --> 00:12:25.680 geometric centr of Bennu which you 322 00:12:23.250 --> 00:12:28.019 can see on the left-hand side of the 323 00:12:25.680 --> 00:12:29.519 graphic we now navigate by surface 324 00:12:28.019 --> 00:12:32.160 features which have allowed us to better 325 00:12:29.519 --> 00:12:35.100 understand characteristics of both Bennu 326 00:12:32.160 --> 00:12:38.069 and the spacecraft that affect the 327 00:12:35.100 --> 00:12:39.839 navigation performance now what's really 328 00:12:38.069 --> 00:12:41.610 impressive about the outcome of our time 329 00:12:39.839 --> 00:12:44.490 in orbit is that we have demonstrated 330 00:12:41.610 --> 00:12:46.920 meter level navigation accuracy which is 331 00:12:44.490 --> 00:12:51.060 even better than the earth based GPS on 332 00:12:46.920 --> 00:12:53.490 your smartphone you can see in this, in 333 00:12:51.060 --> 00:12:55.589 these two NavCam views from orbit and as 334 00:12:53.490 --> 00:12:56.570 Dante mentioned that Bennu is very dense 335 00:12:55.589 --> 00:12:58.100 of boulders which 336 00:12:56.570 --> 00:13:00.680 make for a more challenging sample 337 00:12:58.100 --> 00:13:03.170 collection luckily our predictive 338 00:13:00.680 --> 00:13:05.360 navigation performance has been 10 times 339 00:13:03.170 --> 00:13:07.730 better than what we expected before we 340 00:13:05.360 --> 00:13:09.290 arrived at Bennu which means we leave it 341 00:13:07.730 --> 00:13:12.890 we will be able to tighten down our 342 00:13:09.290 --> 00:13:17.150 analyses and and target the more precise 343 00:13:12.890 --> 00:13:21.140 bull's eye tag moving on to the slide 3 344 00:13:17.150 --> 00:13:23.270 now just six days after we got into 345 00:13:21.140 --> 00:13:25.820 orbit we've observed our first particle 346 00:13:23.270 --> 00:13:27.080 event and this discovery was only 347 00:13:25.820 --> 00:13:28.790 observed because of our optical 348 00:13:27.080 --> 00:13:31.310 navigation method of taking long 349 00:13:28.790 --> 00:13:34.310 exposure images of stars which helped 350 00:13:31.310 --> 00:13:37.070 refine our precise measurements so given 351 00:13:34.310 --> 00:13:39.500 the this image based and dynamical 352 00:13:37.070 --> 00:13:42.620 nature of this phenomenon our navigation 353 00:13:39.500 --> 00:13:44.780 team has been able to quickly build up a 354 00:13:42.620 --> 00:13:47.690 toolset to characterize the behaviors of 355 00:13:44.780 --> 00:13:50.300 these particles so work is underway to 356 00:13:47.690 --> 00:13:54.470 use these sparse data just a few images 357 00:13:50.300 --> 00:13:57.020 of pixels emitting from the asteroid to 358 00:13:54.470 --> 00:13:58.730 trace these particles back to the 359 00:13:57.020 --> 00:14:00.560 surface as well as predict where they 360 00:13:58.730 --> 00:14:03.860 were heading 361 00:14:00.560 --> 00:14:05.630 so with that I will close by giving big 362 00:14:03.860 --> 00:14:07.250 kudos to all the hard works and members 363 00:14:05.630 --> 00:14:08.600 of the navigation team and our entire 364 00:14:07.250 --> 00:14:10.880 mission team who have really 365 00:14:08.600 --> 00:14:14.270 demonstrated amazing and unprecedented 366 00:14:10.880 --> 00:14:15.560 capability on this mission so far so 367 00:14:14.270 --> 00:14:17.150 I'll hand the floor over to rich burns 368 00:14:15.560 --> 00:14:19.030 who will further speak to this graphic 369 00:14:17.150 --> 00:14:22.130 before moving on 370 00:14:19.030 --> 00:14:24.500 thank you very much Coralie so it's 371 00:14:22.130 --> 00:14:26.960 currently mentioned we were only six 372 00:14:24.500 --> 00:14:29.720 days in orbit of the smallest orbit ever 373 00:14:26.960 --> 00:14:32.000 around the planetary body when we 374 00:14:29.720 --> 00:14:35.420 observed this event you can imagine we 375 00:14:32.000 --> 00:14:37.220 were mostly concerned about particles 376 00:14:35.420 --> 00:14:40.670 being ejected from the surface of the 377 00:14:37.220 --> 00:14:42.610 asteroid unexpectedly and so that 378 00:14:40.670 --> 00:14:45.050 prompted us to do a quick turnaround 379 00:14:42.610 --> 00:14:48.470 safety assessment in other words how 380 00:14:45.050 --> 00:14:50.810 likely was the spacecraft to be impacted 381 00:14:48.470 --> 00:14:54.340 by these particles were we safe in orbit 382 00:14:50.810 --> 00:14:56.930 we did that very quickly within a day 383 00:14:54.340 --> 00:14:58.460 using the available information we had 384 00:14:56.930 --> 00:15:02.060 and techniques that we were familiar 385 00:14:58.460 --> 00:15:05.630 with with a four low-earth orbit 386 00:15:02.060 --> 00:15:08.720 collision avoidance calculations these 387 00:15:05.630 --> 00:15:09.760 calculations we we did with three 388 00:15:08.720 --> 00:15:11.680 independent party 389 00:15:09.760 --> 00:15:14.650 and all came up with similar results 390 00:15:11.680 --> 00:15:17.160 showing that we were had very low likely 391 00:15:14.650 --> 00:15:19.380 hit likelihood of seeing an impact 392 00:15:17.160 --> 00:15:23.920 resulting from one of these particles 393 00:15:19.380 --> 00:15:27.700 safety analysis was further refined and 394 00:15:23.920 --> 00:15:30.370 and informed by subsequent observations 395 00:15:27.700 --> 00:15:32.560 Dante mentioned the 11 events that we've 396 00:15:30.370 --> 00:15:35.350 seen three of them have been major like 397 00:15:32.560 --> 00:15:38.050 this one you see on this graphic all of 398 00:15:35.350 --> 00:15:39.700 those all that information led us to the 399 00:15:38.050 --> 00:15:43.480 conclusion that we work the spacecraft 400 00:15:39.700 --> 00:15:46.930 was safe in orbit and and we persisted 401 00:15:43.480 --> 00:15:49.960 there to observe observe these events as 402 00:15:46.930 --> 00:15:53.920 the orbital environment was the optimal 403 00:15:49.960 --> 00:15:59.050 for such a such observations if move on 404 00:15:53.920 --> 00:16:01.150 to my first graphic please so what you 405 00:15:59.050 --> 00:16:04.810 see here is another high-resolution 406 00:16:01.150 --> 00:16:09.220 image of a location on the asteroid with 407 00:16:04.810 --> 00:16:11.140 an overlay of a circular region we're 408 00:16:09.220 --> 00:16:15.010 calling the original target area this is 409 00:16:11.140 --> 00:16:17.590 the accuracy with which osiris-rex was 410 00:16:15.010 --> 00:16:19.770 designed to touch the asteroid to 411 00:16:17.590 --> 00:16:24.040 collect the sample so we were looking 412 00:16:19.770 --> 00:16:26.550 originally for a 25 meter radius hazard 413 00:16:24.040 --> 00:16:31.450 free zone you can see from this image 414 00:16:26.550 --> 00:16:33.580 this isn't it and the and the asteroid 415 00:16:31.450 --> 00:16:36.760 is so rugged that there is unlikely to 416 00:16:33.580 --> 00:16:38.920 be any 25 meter radius hazard free zones 417 00:16:36.760 --> 00:16:41.320 what do I mean by hazards those big 418 00:16:38.920 --> 00:16:43.780 boulders represent hazards as do tilts 419 00:16:41.320 --> 00:16:46.510 severe tilts on the surface and slopes 420 00:16:43.780 --> 00:16:49.150 on the surface of the asteroids you do 421 00:16:46.510 --> 00:16:53.710 see an upper left-hand corner a region 422 00:16:49.150 --> 00:16:56.380 of small grained samples which would may 423 00:16:53.710 --> 00:16:59.950 be appropriate for a sample collection 424 00:16:56.380 --> 00:17:02.410 of course that area is much smaller than 425 00:16:59.950 --> 00:17:06.610 the area outlined in in white here the 426 00:17:02.410 --> 00:17:08.920 25 meter radius circle however our 427 00:17:06.610 --> 00:17:11.100 system performance as has been noted by 428 00:17:08.920 --> 00:17:14.589 both Dante and Coralie has been 429 00:17:11.100 --> 00:17:17.079 extraordinary today our spacecraft built 430 00:17:14.589 --> 00:17:19.930 by Lockheed Martin has performed 431 00:17:17.079 --> 00:17:21.770 manoeuvres with very high levels of 432 00:17:19.930 --> 00:17:23.839 accuracy and precision 433 00:17:21.770 --> 00:17:25.850 allowing us to do things like stay in 434 00:17:23.839 --> 00:17:28.400 orbit without trim maneuvers as Coralie 435 00:17:25.850 --> 00:17:31.610 mentioned our navigation performance has 436 00:17:28.400 --> 00:17:37.090 been exquisite the modeling that the 437 00:17:31.610 --> 00:17:40.300 navigation team collaborating with a 438 00:17:37.090 --> 00:17:43.040 with Goddard and KinetX both 439 00:17:40.300 --> 00:17:45.350 collaborating has been extraordinary in 440 00:17:43.040 --> 00:17:47.600 the level of modeling the fidelity of 441 00:17:45.350 --> 00:17:49.820 the modeling of things like solar 442 00:17:47.600 --> 00:17:53.420 radiation pressure Andry radiation from 443 00:17:49.820 --> 00:17:55.670 the spacecraft has been extraordinary so 444 00:17:53.420 --> 00:17:59.690 we feel confident that our systems and 445 00:17:55.670 --> 00:18:03.230 our teams are up to the task of a sample 446 00:17:59.690 --> 00:18:05.750 of a tagging - a sample collection site 447 00:18:03.230 --> 00:18:09.050 of much smaller area than was currently 448 00:18:05.750 --> 00:18:10.910 than was previously envisioned that's 449 00:18:09.050 --> 00:18:13.790 what gives us confidence to move forward 450 00:18:10.910 --> 00:18:16.280 with what we're calling bullseye tag so 451 00:18:13.790 --> 00:18:19.070 bullseye tag you can imagine you're just 452 00:18:16.280 --> 00:18:20.600 shooting at a dart at a dart board just 453 00:18:19.070 --> 00:18:22.340 trying to hit the board well now we're 454 00:18:20.600 --> 00:18:26.360 going to try to hit the center of the 455 00:18:22.340 --> 00:18:29.120 bullseye we feel like the performance of 456 00:18:26.360 --> 00:18:30.800 the system and the team supports that 457 00:18:29.120 --> 00:18:35.710 notion and we are working actively to 458 00:18:30.800 --> 00:18:38.540 make it happen and next graphic please 459 00:18:35.710 --> 00:18:41.540 what you see on the next graphic graphic 460 00:18:38.540 --> 00:18:45.020 is just an animation of our tag sequence 461 00:18:41.540 --> 00:18:48.170 so we will the spacecraft will leave 462 00:18:45.020 --> 00:18:52.390 orbit and you'll see a deployment of the 463 00:18:48.170 --> 00:18:55.820 TAGSAM armed with the TAGSAM head 464 00:18:52.390 --> 00:18:59.080 featured in that deployment the 465 00:18:55.820 --> 00:19:02.050 spacecraft will make two manoeuvres to 466 00:18:59.080 --> 00:19:07.910 descend to the surface of the asteroid 467 00:19:02.050 --> 00:19:10.910 and we will not land on the asteroid 468 00:19:07.910 --> 00:19:13.820 this the the spacecraft will touch the 469 00:19:10.910 --> 00:19:17.480 asteroid with this with the head the 470 00:19:13.820 --> 00:19:21.920 sample head hopefully on a level spot 471 00:19:17.480 --> 00:19:24.490 and we will expel a nitrogen pressurized 472 00:19:21.920 --> 00:19:27.380 nitrogen gas to disturb the regolith 473 00:19:24.490 --> 00:19:30.050 that regolith will be collected within 474 00:19:27.380 --> 00:19:34.730 the sample head itself which looks like 475 00:19:30.050 --> 00:19:36.679 a an air filter more or less 476 00:19:34.730 --> 00:19:38.750 that fine-grained sample will be 477 00:19:36.679 --> 00:19:42.980 collected there we'll back away from the 478 00:19:38.750 --> 00:19:44.660 asteroid and and then once we once we're 479 00:19:42.980 --> 00:19:46.640 away from the asteroid we have some 480 00:19:44.660 --> 00:19:49.370 techniques that we'll use to measure the 481 00:19:46.640 --> 00:19:51.950 the amount the size of the sample that 482 00:19:49.370 --> 00:19:55.820 we got and then we'll stow that sample 483 00:19:51.950 --> 00:19:58.540 in our sample return capsule with all 484 00:19:55.820 --> 00:20:02.570 that said I want to turn it back over to 485 00:19:58.540 --> 00:20:04.370 Dante and let him close things out so 486 00:20:02.570 --> 00:20:07.730 just to summarize first of all the 487 00:20:04.370 --> 00:20:09.770 osiris-rex team continues to perform at 488 00:20:07.730 --> 00:20:11.990 an amazing level of professionalism and 489 00:20:09.770 --> 00:20:13.940 precision and it's an honor to be the 490 00:20:11.990 --> 00:20:15.169 leader of this program I couldn't be 491 00:20:13.940 --> 00:20:17.600 more proud of everything that's been 492 00:20:15.169 --> 00:20:19.820 accomplished so far and because of that 493 00:20:17.600 --> 00:20:21.650 it gives me great confidence that we're 494 00:20:19.820 --> 00:20:26.360 going to be able to target a bull's eye 495 00:20:21.650 --> 00:20:28.940 tag event or summer of 2020 and get that 496 00:20:26.360 --> 00:20:31.850 precious sample for stow and return back 497 00:20:28.940 --> 00:20:33.530 to Earth Bennu has turned out to be an 498 00:20:31.850 --> 00:20:35.870 ideal target from a compositional 499 00:20:33.530 --> 00:20:37.820 perspective we are seeing abundant water 500 00:20:35.870 --> 00:20:39.740 bearing minerals on the surface and 501 00:20:37.820 --> 00:20:42.320 through the magnetite detection 502 00:20:39.740 --> 00:20:44.690 inference of intense aqueous activity in 503 00:20:42.320 --> 00:20:46.610 the past history of this asteroid it 504 00:20:44.690 --> 00:20:48.590 does present us challenge it's a more 505 00:20:46.610 --> 00:20:51.169 rugged surface than we had predicted 506 00:20:48.590 --> 00:20:53.000 from our ground-based astronomy but we 507 00:20:51.169 --> 00:20:55.309 feel like there are patches of 508 00:20:53.000 --> 00:20:56.929 fine-grained material on the surface 509 00:20:55.309 --> 00:20:59.630 that we can collect with the TAGSAM 510 00:20:56.929 --> 00:21:00.890 device and of course as I hope Coralie 511 00:20:59.630 --> 00:21:03.440 has convinced you the flight dynamics 512 00:21:00.890 --> 00:21:04.460 and navigation team is absolutely the 513 00:21:03.440 --> 00:21:06.200 best in the world 514 00:21:04.460 --> 00:21:07.880 they're cutting edge astrodynamics 515 00:21:06.200 --> 00:21:09.980 techniques are not only going to make 516 00:21:07.880 --> 00:21:11.480 sure the spacecraft remains safe but 517 00:21:09.980 --> 00:21:13.040 also that we collect all the scientific 518 00:21:11.480 --> 00:21:14.809 data we need to make the best sample 519 00:21:13.040 --> 00:21:16.820 site selection decision possible and 520 00:21:14.809 --> 00:21:19.429 ultimately guide us down to get that 521 00:21:16.820 --> 00:21:21.440 material off the surface and then almost 522 00:21:19.429 --> 00:21:22.880 more impressively we have such a tight 523 00:21:21.440 --> 00:21:25.010 coupling between the science and 524 00:21:22.880 --> 00:21:27.080 engineering groups on this program that 525 00:21:25.010 --> 00:21:28.429 they're also making a major contribution 526 00:21:27.080 --> 00:21:30.380 to characterizing these particle 527 00:21:28.429 --> 00:21:31.820 ejection events and the tools and 528 00:21:30.380 --> 00:21:34.160 procedures and analysis capabilities 529 00:21:31.820 --> 00:21:35.720 that they bring to the team are going to 530 00:21:34.160 --> 00:21:37.970 end up producing some of the greatest 531 00:21:35.720 --> 00:21:39.679 scientific discoveries definitely not 532 00:21:37.970 --> 00:21:41.840 what we expected to see if the asteroid 533 00:21:39.679 --> 00:21:42.919 but an excellent opportunity for us to 534 00:21:41.840 --> 00:21:45.350 understand active 535 00:21:42.919 --> 00:21:47.119 asteroids volatile ejection and loss from 536 00:21:45.350 --> 00:21:48.710 these bodies and overall the 537 00:21:47.119 --> 00:21:50.480 distribution of this kind of material in 538 00:21:48.710 --> 00:21:51.950 the solar system and ultimately its 539 00:21:50.480 --> 00:21:53.899 pathway to delivery to the surface of 540 00:21:51.950 --> 00:21:55.720 the earth so thanks to everybody on the 541 00:21:53.899 --> 00:21:58.369 team for their hard work today and 542 00:21:55.720 --> 00:22:03.830 buckle up best times are ahead of us and 543 00:21:58.369 --> 00:22:06.409 it's going to be a great ride thanks 544 00:22:03.830 --> 00:22:08.119 Thank you, Dante. Operator, we're now ready 545 00:22:06.409 --> 00:22:10.119 to take questions from the media please 546 00:22:08.119 --> 00:22:12.950 state your name and affiliation operator 547 00:22:10.119 --> 00:22:14.450 thank you at this time we will begin the 548 00:22:12.950 --> 00:22:16.159 question and answer session if you'd 549 00:22:14.450 --> 00:22:18.139 like to ask a question please press star 550 00:22:16.159 --> 00:22:20.029 one unmute your phone and record your 551 00:22:18.139 --> 00:22:22.519 name when prompted withdraw your 552 00:22:20.029 --> 00:22:25.600 question please please press star 2 one 553 00:22:22.519 --> 00:22:25.600 moment please for the first question 554 00:22:28.059 --> 00:22:34.850 Ivan Colon your line is open 555 00:22:31.509 --> 00:22:37.249 thank you in terms of a probability how 556 00:22:34.850 --> 00:22:39.499 much more risky do you expect the 557 00:22:37.249 --> 00:22:44.659 sampling operation to be because of what 558 00:22:39.499 --> 00:22:46.489 you found out so this is rich I can I 559 00:22:44.659 --> 00:22:48.590 can take that one we don't have a 560 00:22:46.489 --> 00:22:51.769 quantification of that yet because we 561 00:22:48.590 --> 00:22:54.739 are still in the process of mapping the 562 00:22:51.769 --> 00:22:57.859 asteroid to identify the candidates a 563 00:22:54.739 --> 00:23:04.850 candidate sample selection sample sites 564 00:22:57.859 --> 00:23:08.840 so we're going to make a sample site 565 00:23:04.850 --> 00:23:11.149 selection in in the summer months and at 566 00:23:08.840 --> 00:23:13.940 that point we'll have a better idea of 567 00:23:11.149 --> 00:23:17.330 the area of the sample site relative to 568 00:23:13.940 --> 00:23:20.119 our previous requirements will this 569 00:23:17.330 --> 00:23:22.429 delay at all the the the sampling 570 00:23:20.119 --> 00:23:27.019 compared to what you you forecast 571 00:23:22.429 --> 00:23:30.999 initially July 20 2000 after no the 572 00:23:27.019 --> 00:23:30.999 answer is no okay thank you 573 00:23:33.970 --> 00:23:40.450 our next question comes from Marina 574 00:23:36.520 --> 00:23:42.940 Curran your line is open hi this is a 575 00:23:40.450 --> 00:23:44.230 question for Dante you said you don't 576 00:23:42.940 --> 00:23:46.300 know for sure what's causing these 577 00:23:44.230 --> 00:23:48.250 ejections but do you have any ideas 578 00:23:46.300 --> 00:23:50.590 based on the study of other active 579 00:23:48.250 --> 00:23:52.420 asteroids and did you expect to see this 580 00:23:50.590 --> 00:23:55.120 kind of activity on Bennu why or why 581 00:23:52.420 --> 00:23:57.550 not thank you for that that's a great 582 00:23:55.120 --> 00:24:00.310 question we certainly did not expect to 583 00:23:57.550 --> 00:24:02.080 see this activity because there's so few 584 00:24:00.310 --> 00:24:04.570 asteroids that are known to be active 585 00:24:02.080 --> 00:24:06.460 there's about a dozen of them of the 586 00:24:04.570 --> 00:24:08.440 800.000 asteroids that we know in the 587 00:24:06.460 --> 00:24:09.940 solar system so the probability that 588 00:24:08.440 --> 00:24:13.180 Bennu would be active we thought was 589 00:24:09.940 --> 00:24:14.920 very very low that said we did plan for 590 00:24:13.180 --> 00:24:16.480 such an event because we thought it 591 00:24:14.920 --> 00:24:18.310 might be possible and we're very 592 00:24:16.480 --> 00:24:20.020 thorough in how we design the mission 593 00:24:18.310 --> 00:24:22.240 and how we approach the risk and safety 594 00:24:20.020 --> 00:24:24.250 assessments and also take advantage of 595 00:24:22.240 --> 00:24:26.470 scientific opportunities so we actually 596 00:24:24.250 --> 00:24:29.440 do have requirements on the mission to 597 00:24:26.470 --> 00:24:31.240 look for dust and gas plumes and we also 598 00:24:29.440 --> 00:24:33.520 have requirements to search for and 599 00:24:31.240 --> 00:24:34.810 characterize any natural satellites that 600 00:24:33.520 --> 00:24:37.540 may be in bound orbits around the 601 00:24:34.810 --> 00:24:39.850 asteroid we did not expect that there 602 00:24:37.540 --> 00:24:41.560 would be ejections of particles that 603 00:24:39.850 --> 00:24:43.750 we're creating natural satellites that 604 00:24:41.560 --> 00:24:46.090 has never been seen before in any solar 605 00:24:43.750 --> 00:24:49.000 system object in history so that's 606 00:24:46.090 --> 00:24:51.400 really exciting and a great opportunity 607 00:24:49.000 --> 00:24:54.310 for us to learn more about not only the 608 00:24:51.400 --> 00:24:56.260 surface of the asteroid but also its 609 00:24:54.310 --> 00:24:57.550 gravity field these are natural gravity 610 00:24:56.260 --> 00:24:59.260 probes and they're orbiting very close 611 00:24:57.550 --> 00:25:01.150 to the asteroids we'll be able to get a 612 00:24:59.260 --> 00:25:03.460 great understanding of the gravity field 613 00:25:01.150 --> 00:25:07.090 and therefore the internal structure of 614 00:25:03.460 --> 00:25:09.100 the asteroid we do have some mechanisms 615 00:25:07.090 --> 00:25:10.690 that are under evaluation with one of 616 00:25:09.100 --> 00:25:12.400 the very first things I did was we 617 00:25:10.690 --> 00:25:14.020 rallied the science team together we 618 00:25:12.400 --> 00:25:16.150 made up a big list of all possible 619 00:25:14.020 --> 00:25:18.820 things that could eject particles from 620 00:25:16.150 --> 00:25:20.830 the surface it's a long list there's a 621 00:25:18.820 --> 00:25:24.220 very creative team and lots of ideas are 622 00:25:20.830 --> 00:25:26.320 out there so my focus right now is full 623 00:25:24.220 --> 00:25:28.030 characterization of what has happened as 624 00:25:26.320 --> 00:25:30.010 I mentioned we have a great data set 625 00:25:28.030 --> 00:25:31.990 that goes from January 11th through 626 00:25:30.010 --> 00:25:34.180 February 18th we're still developing 627 00:25:31.990 --> 00:25:35.770 software and analysis tools to really 628 00:25:34.180 --> 00:25:37.680 understand what's in that information 629 00:25:35.770 --> 00:25:40.500 and my first objective 630 00:25:37.680 --> 00:25:42.810 which is underway is to compile a table 631 00:25:40.500 --> 00:25:44.790 of the constraints basically what do we 632 00:25:42.810 --> 00:25:47.910 know about the size of the particles the 633 00:25:44.790 --> 00:25:50.640 energy of the events the frequency the 634 00:25:47.910 --> 00:25:52.110 composition the source regions etc and 635 00:25:50.640 --> 00:25:54.120 once I have all of that information 636 00:25:52.110 --> 00:25:55.770 compiled then we'll start to go through 637 00:25:54.120 --> 00:25:57.300 our different possible mechanisms then 638 00:25:55.770 --> 00:26:08.670 evaluate which one we think is the most 639 00:25:57.300 --> 00:26:10.830 likely thank you thank you our next 640 00:26:08.670 --> 00:26:14.070 question comes from Mark Gaucho 641 00:26:10.830 --> 00:26:16.170 your line is open yes good afternoon 642 00:26:14.070 --> 00:26:18.660 ladies and gentlemen first off 643 00:26:16.170 --> 00:26:21.180 congratulations on the incredible 644 00:26:18.660 --> 00:26:24.270 achievements you've made by already 645 00:26:21.180 --> 00:26:28.650 making the long journey to the asteroid 646 00:26:24.270 --> 00:26:32.270 Bennu in talking about the discharges 647 00:26:28.650 --> 00:26:36.330 of particles are these actually uh 648 00:26:32.270 --> 00:26:40.650 storms or small ejections of particles 649 00:26:36.330 --> 00:26:45.540 are you now looking at at this seeing 650 00:26:40.650 --> 00:26:48.150 this as looking at your your bull's eye 651 00:26:45.540 --> 00:26:50.250 collection location as it being 652 00:26:48.150 --> 00:26:52.620 something that you might have to wade 653 00:26:50.250 --> 00:26:55.200 through a long period of these type of 654 00:26:52.620 --> 00:26:58.290 particle ejections or storms the answer 655 00:26:55.200 --> 00:27:00.240 that turn absolutely we're trying to 656 00:26:58.290 --> 00:27:02.070 understand the nature of the ejection 657 00:27:00.240 --> 00:27:04.110 events a couple of things that we do 658 00:27:02.070 --> 00:27:06.540 know is that they are discrete events 659 00:27:04.110 --> 00:27:08.160 they happen near instantaneously and 660 00:27:06.540 --> 00:27:09.600 whenever we see a large number of 661 00:27:08.160 --> 00:27:11.550 particles leaving the surface of the 662 00:27:09.600 --> 00:27:15.060 asteroid they seem to be coming from a 663 00:27:11.550 --> 00:27:17.280 single location we are still working to 664 00:27:15.060 --> 00:27:18.870 determine the exact locations of all the 665 00:27:17.280 --> 00:27:20.700 events that's been observed to date and 666 00:27:18.870 --> 00:27:22.350 I think Coralie can probably tell us a 667 00:27:20.700 --> 00:27:24.240 little bit more because it's the flight 668 00:27:22.350 --> 00:27:26.460 dynamics tools and analyses that are 669 00:27:24.240 --> 00:27:28.230 helping us constrain those and we're 670 00:27:26.460 --> 00:27:31.080 also trying to understand what might be 671 00:27:28.230 --> 00:27:33.960 the driving forces we did go through 672 00:27:31.080 --> 00:27:36.270 perihelion on January 10th so that was 673 00:27:33.960 --> 00:27:38.640 just four days after the first event was 674 00:27:36.270 --> 00:27:40.440 observed but as we said earlier that was 675 00:27:38.640 --> 00:27:42.300 only one week after we got into orbit 676 00:27:40.440 --> 00:27:44.850 when these things were really observable 677 00:27:42.300 --> 00:27:45.549 so we don't know if it's in fact related 678 00:27:44.850 --> 00:27:47.919 to our 679 00:27:45.549 --> 00:27:49.629 closest approach to the Sun and Bennu's 680 00:27:47.919 --> 00:27:51.549 orbit is pretty eccentric it goes from 681 00:27:49.629 --> 00:27:53.710 about point eight nine astronomical 682 00:27:51.549 --> 00:27:56.139 units at the closest approach to the Sun 683 00:27:53.710 --> 00:27:59.259 or perihelion up to one point three five 684 00:27:56.139 --> 00:28:00.909 au aphelion or its farthest point from 685 00:27:59.259 --> 00:28:02.739 the Sun though there's there is a 686 00:28:00.909 --> 00:28:05.230 speculation that this might be related 687 00:28:02.739 --> 00:28:07.330 to the close approach but we haven't 688 00:28:05.230 --> 00:28:09.999 confirmed that yet we have seen the 689 00:28:07.330 --> 00:28:12.789 events continuing into the lake February 690 00:28:09.999 --> 00:28:14.619 timeframe and we're not seeing them but 691 00:28:12.789 --> 00:28:16.210 we also have left orbit and we're much 692 00:28:14.619 --> 00:28:17.559 farther away from the asteroid so 693 00:28:16.210 --> 00:28:20.470 they're not as observable as they were 694 00:28:17.559 --> 00:28:21.850 before so all of these are open 695 00:28:20.470 --> 00:28:23.649 questions it's one of the greatest 696 00:28:21.850 --> 00:28:25.269 things about being a scientist is you 697 00:28:23.649 --> 00:28:27.820 get to go chase down your theories and 698 00:28:25.269 --> 00:28:31.090 click more data to understand them but 699 00:28:27.820 --> 00:28:32.859 Bennu is really teasing us with this I 700 00:28:31.090 --> 00:28:34.239 think it's really every time we think we 701 00:28:32.859 --> 00:28:36.850 understand what's going on a new 702 00:28:34.239 --> 00:28:38.679 manifestation occurs and we go back to 703 00:28:36.850 --> 00:28:41.139 the drawing board and start thinking 704 00:28:38.679 --> 00:28:42.820 over it again so we're super excited but 705 00:28:41.139 --> 00:28:44.669 we're also being very diligent and 706 00:28:42.820 --> 00:28:46.539 careful as we process the data and 707 00:28:44.669 --> 00:28:48.070 Coralie why don't you talk a little bit 708 00:28:46.539 --> 00:28:51.899 about the work you're doing to actually 709 00:28:48.070 --> 00:28:54.850 locate the ejection sites on the surface 710 00:28:51.899 --> 00:28:57.730 sure well what's challenging is that we 711 00:28:54.850 --> 00:29:00.970 have these you know 2d images of 712 00:28:57.730 --> 00:29:05.289 particles and we can what's challenging 713 00:29:00.970 --> 00:29:09.039 is we are trying to link these particles 714 00:29:05.289 --> 00:29:11.019 from one image to the next and then back 715 00:29:09.039 --> 00:29:14.230 out we can measure things in the image 716 00:29:11.019 --> 00:29:17.889 plane in 2d space the position and 717 00:29:14.230 --> 00:29:20.799 movement of the particles and what we're 718 00:29:17.889 --> 00:29:24.239 focusing on is trying to make some good 719 00:29:20.799 --> 00:29:27.249 assumptions about how to project those 720 00:29:24.239 --> 00:29:30.249 2d measurements into 3d space so that we 721 00:29:27.249 --> 00:29:34.330 can measure the 3d velocities the cone 722 00:29:30.249 --> 00:29:36.879 or shape of the ejection and trace the 723 00:29:34.330 --> 00:29:40.840 particles back to an origin site on the 724 00:29:36.879 --> 00:29:44.820 surface as well as predict their their 725 00:29:40.840 --> 00:29:49.799 orbits sub orbits or you know hyperbolic 726 00:29:44.820 --> 00:29:51.940 escape escape trajectories from there 727 00:29:49.799 --> 00:29:55.049 thank you very much you are learning 728 00:29:51.940 --> 00:29:55.049 quite a bit thank you 729 00:29:59.760 --> 00:30:05.320 thank you our next question comes from 730 00:30:02.460 --> 00:30:06.330 Malcolm Ritter Associated Press your 731 00:30:05.320 --> 00:30:08.890 line is open 732 00:30:06.330 --> 00:30:11.230 thank you very much I what I hope is a 733 00:30:08.890 --> 00:30:13.150 simple question you talked about 734 00:30:11.230 --> 00:30:14.290 recovering the sample that you want to 735 00:30:13.150 --> 00:30:16.750 recover and bring back to earth you 736 00:30:14.290 --> 00:30:19.780 talked about this being pieces of 737 00:30:16.750 --> 00:30:23.920 regolith of you know below a certain 738 00:30:19.780 --> 00:30:25.270 size and my audience has no idea what 739 00:30:23.920 --> 00:30:28.030 we're talking about are we talking about 740 00:30:25.270 --> 00:30:30.850 dirt or gravel or pebbles or what is 741 00:30:28.030 --> 00:30:33.730 kind of an everyday English word that 742 00:30:30.850 --> 00:30:36.580 would that would describe the stuff 743 00:30:33.730 --> 00:30:38.920 you're going to collect? This 744 00:30:36.580 --> 00:30:41.890 is Dante so regolith is the term that we 745 00:30:38.920 --> 00:30:44.380 use to describe a loose blanket of rock 746 00:30:41.890 --> 00:30:46.150 and gravel usually on the surface of an 747 00:30:44.380 --> 00:30:48.400 airless body so we talked about the 748 00:30:46.150 --> 00:30:51.130 regolith on the moon or on Mercury and 749 00:30:48.400 --> 00:30:53.320 on asteroids so basically what we're 750 00:30:51.130 --> 00:30:55.990 seeing Bennu being a rubble pile we've 751 00:30:53.320 --> 00:30:57.850 got boulders as large as 80 meters and 752 00:30:55.990 --> 00:31:00.700 we were seeing particles right now down 753 00:30:57.850 --> 00:31:02.500 to a few centimeters basically limited 754 00:31:00.700 --> 00:31:04.900 by the resolution of the images we've 755 00:31:02.500 --> 00:31:06.340 acquired to date so in a sense all of 756 00:31:04.900 --> 00:31:08.650 that would be considered regolith 757 00:31:06.340 --> 00:31:10.810 because we don't have bedrock or the 758 00:31:08.650 --> 00:31:13.870 solid material that makes up the bulk of 759 00:31:10.810 --> 00:31:15.730 the asteroid for osiris-rex specifically 760 00:31:13.870 --> 00:31:18.310 we're looking for fine particulate 761 00:31:15.730 --> 00:31:20.950 regolith and that's driven by the 762 00:31:18.310 --> 00:31:22.750 capability of the sample collector which 763 00:31:20.950 --> 00:31:25.600 can pick up particles about two 764 00:31:22.750 --> 00:31:28.000 centimeters in diameter and smaller so 765 00:31:25.600 --> 00:31:30.640 we're looking for the fine regolith that 766 00:31:28.000 --> 00:31:34.480 is capable of being ingested by the 767 00:31:30.640 --> 00:31:36.760 sampling mechanism so I'm from what you 768 00:31:34.480 --> 00:31:40.240 say I think 270 meters in diameter 769 00:31:36.760 --> 00:31:41.950 that's what a tenth of an inch for 770 00:31:40.240 --> 00:31:45.660 basically yeah so we're basically 771 00:31:41.950 --> 00:31:50.140 looking at there gravel and dirt? I mean 772 00:31:45.660 --> 00:31:52.840 is that a fair way to describe this? Yeah 773 00:31:50.140 --> 00:31:56.320 gravel and sand sized particles we're looking 774 00:31:52.840 --> 00:31:59.670 at the geologic scale so absolutely yes 775 00:31:56.320 --> 00:32:07.450 or grab a little smaller then right yeah 776 00:31:59.670 --> 00:32:08.830 okay and again I'm struck in your paper 777 00:32:07.450 --> 00:32:11.560 you were first author on a paper in 778 00:32:08.830 --> 00:32:13.960 nature that just went live saying that 779 00:32:11.560 --> 00:32:16.600 you know the your the unexpected small 780 00:32:13.960 --> 00:32:18.280 size of safe collection sites 781 00:32:16.600 --> 00:32:20.140 you said the sampling of which poses a 782 00:32:18.280 --> 00:32:24.220 substantial challenge to mission success 783 00:32:20.140 --> 00:32:26.230 and yet here you sound like you're going 784 00:32:24.220 --> 00:32:29.110 to like it's going to be a breeze not a 785 00:32:26.230 --> 00:32:30.760 problem so I'm kind of struck by you 786 00:32:29.110 --> 00:32:31.660 know how confident are you can really 787 00:32:30.760 --> 00:32:34.210 pull this off 788 00:32:31.660 --> 00:32:36.280 sure and I would say everything we're 789 00:32:34.210 --> 00:32:37.990 doing is a substantial challenge and so 790 00:32:36.280 --> 00:32:40.480 we shouldn't diminish the enormous 791 00:32:37.990 --> 00:32:43.210 amount of effort that it takes to make 792 00:32:40.480 --> 00:32:45.940 something like this happen so you know 793 00:32:43.210 --> 00:32:47.650 NASA has a long history of doing very 794 00:32:45.940 --> 00:32:49.600 difficult things and making them look 795 00:32:47.650 --> 00:32:53.680 easy and that is continuing on with the 796 00:32:49.600 --> 00:32:55.960 osiris-rex mission and it is not done it 797 00:32:53.680 --> 00:32:58.090 is not trivial to deliver a spacecraft 798 00:32:55.960 --> 00:32:59.770 with meter scale resolution to the 799 00:32:58.090 --> 00:33:01.510 surface of an asteroid in a microgravity 800 00:32:59.770 --> 00:33:02.770 environment and we take that challenge 801 00:33:01.510 --> 00:33:05.320 very seriously 802 00:33:02.770 --> 00:33:07.720 and the challenge got a lot harder when 803 00:33:05.320 --> 00:33:10.510 we saw the true nature of Bennu's surface 804 00:33:07.720 --> 00:33:12.250 but I am confident that this team is up 805 00:33:10.510 --> 00:33:14.110 to that substantial challenge and that 806 00:33:12.250 --> 00:33:16.120 we will ultimately develop this bullseye 807 00:33:14.110 --> 00:33:17.590 tag capability and be able to 808 00:33:16.120 --> 00:33:28.390 successfully collect the sample from the 809 00:33:17.590 --> 00:33:31.480 surface okay very good thank you all 810 00:33:28.390 --> 00:33:35.490 next our next question comes from Doyle 811 00:33:31.480 --> 00:33:37.810 Rice USA today your line is open 812 00:33:35.490 --> 00:33:41.830 good afternoon thanks for doing this 813 00:33:37.810 --> 00:33:43.840 very interesting stuff I just couple of 814 00:33:41.830 --> 00:33:46.810 quick questions for you just kind of on 815 00:33:43.840 --> 00:33:49.030 a bigger term scale here there's not 816 00:33:46.810 --> 00:33:50.800 anything that you've discovered today or 817 00:33:49.030 --> 00:33:53.650 announcing doesn't really have any 818 00:33:50.800 --> 00:33:55.780 specific impact on you know whether or 819 00:33:53.650 --> 00:33:58.000 not this this particular asteroid will 820 00:33:55.780 --> 00:34:00.010 come closer or farther away to earth 821 00:33:58.000 --> 00:34:03.220 over the next few hundred years it's not 822 00:34:00.010 --> 00:34:05.950 really this doesn't really you know leap 823 00:34:03.220 --> 00:34:07.810 out as a major discovery for whether or 824 00:34:05.950 --> 00:34:09.760 not it's going to potentially come close 825 00:34:07.810 --> 00:34:11.620 to the earth looking at the British 826 00:34:09.760 --> 00:34:14.260 tabloids today they all say that it's 827 00:34:11.620 --> 00:34:15.669 you know it's about ready to hit or some 828 00:34:14.260 --> 00:34:19.630 crazy thing and I just wondered what 829 00:34:15.669 --> 00:34:22.909 your overall perspective is on that well 830 00:34:19.630 --> 00:34:25.549 one of the words in the acronym 831 00:34:22.909 --> 00:34:27.619 OSIRIS-REx is security and Bennu is known as 832 00:34:25.549 --> 00:34:29.539 they potentially hazardous asteroid so 833 00:34:27.619 --> 00:34:31.730 one of our objectives is to really 834 00:34:29.539 --> 00:34:34.069 understand the likelihood that Bennu is 835 00:34:31.730 --> 00:34:35.929 going to impact the earth we have done a 836 00:34:34.069 --> 00:34:38.329 lot of that work even pre-launch with 837 00:34:35.929 --> 00:34:41.059 our extensive astronomical campaign and 838 00:34:38.329 --> 00:34:44.599 we have given an assessment of about a 1 839 00:34:41.059 --> 00:34:46.849 and 2700 chance of an impact late in the 840 00:34:44.599 --> 00:34:48.589 22nd century we haven't learned anything 841 00:34:46.849 --> 00:34:52.460 that would cause us to change that 842 00:34:48.589 --> 00:34:55.460 estimate of Bennu itself impacting but I 843 00:34:52.460 --> 00:34:57.710 will say one of the fun and exciting 844 00:34:55.460 --> 00:34:59.660 offshoots of the particles as we do see 845 00:34:57.710 --> 00:35:01.789 these things leaving the vicinity of the 846 00:34:59.660 --> 00:35:03.410 asteroid and so we think there's a 847 00:35:01.789 --> 00:35:05.509 reasonable probability that there might 848 00:35:03.410 --> 00:35:07.509 actually be a meteor shower associated 849 00:35:05.509 --> 00:35:10.160 with Bennu and small particles might be 850 00:35:07.509 --> 00:35:12.920 coming in the sky and so that would 851 00:35:10.160 --> 00:35:15.109 happen in late September every year and 852 00:35:12.920 --> 00:35:16.670 it would be dominantly occurring in the 853 00:35:15.109 --> 00:35:18.829 southern hemisphere so we're working 854 00:35:16.670 --> 00:35:21.769 with our colleagues at the SETI 855 00:35:18.829 --> 00:35:23.809 Institute in California to set up some 856 00:35:21.769 --> 00:35:25.549 monitoring cameras and actually see if 857 00:35:23.809 --> 00:35:27.349 they've been you if there is a Bennu's 858 00:35:25.549 --> 00:35:29.630 meteor shower in September every year 859 00:35:27.349 --> 00:35:31.700 and that will help us with the science 860 00:35:29.630 --> 00:35:33.140 understanding these particle events 861 00:35:31.700 --> 00:35:35.720 because it will give us a much longer 862 00:35:33.140 --> 00:35:37.609 timeline about how frequently and how 863 00:35:35.720 --> 00:35:39.589 energetic and how many particles may 864 00:35:37.609 --> 00:35:46.630 have been coming off over thousands of 865 00:35:39.589 --> 00:35:46.630 years of Bennu history ok thank you 866 00:35:50.200 --> 00:35:58.089 the line is now open 867 00:35:52.269 --> 00:36:03.109 Kenneth Chang New York Times your line is open 868 00:35:58.089 --> 00:36:05.329 thank you my question is um vehicle to 869 00:36:03.109 --> 00:36:09.109 show that the Hayabusa to mission is 870 00:36:05.329 --> 00:36:11.000 that it also tried to be this spinning 871 00:36:09.109 --> 00:36:13.640 top with a ridge and lots of boulders 872 00:36:11.000 --> 00:36:17.210 that trying to be much more difficult to 873 00:36:13.640 --> 00:36:20.059 examine them initially anticipated just 874 00:36:17.210 --> 00:36:22.690 wanting to tell you something about the 875 00:36:20.059 --> 00:36:25.009 formation process of these rubble piles 876 00:36:22.690 --> 00:36:26.990 that's a great question Kenneth and 877 00:36:25.009 --> 00:36:29.750 absolutely you know having two 878 00:36:26.990 --> 00:36:31.519 spacecraft at two of these objects gives 879 00:36:29.750 --> 00:36:34.050 us an enormous opportunity to advance 880 00:36:31.519 --> 00:36:36.060 our understanding of the field 881 00:36:34.050 --> 00:36:38.130 and I would say already a lot of our 882 00:36:36.060 --> 00:36:41.550 ideas for how the spinning top shape 883 00:36:38.130 --> 00:36:43.890 formed are not being supported by the 884 00:36:41.550 --> 00:36:45.570 data that we've collected so far for 885 00:36:43.890 --> 00:36:48.030 example one of the things you reported 886 00:36:45.570 --> 00:36:49.980 in the nature papers and also at the 887 00:36:48.030 --> 00:36:51.930 lunar planetary science conference today 888 00:36:49.980 --> 00:36:54.480 is that there's a large number of impact 889 00:36:51.930 --> 00:36:56.880 craters on the equatorial ridge of Bennu 890 00:36:54.480 --> 00:36:58.620 which makes it look like the surface is 891 00:36:56.880 --> 00:37:00.840 a hundred million to maybe a billion 892 00:36:58.620 --> 00:37:03.090 years old which implies that the 893 00:37:00.840 --> 00:37:05.550 spinning top shape in that equatorial 894 00:37:03.090 --> 00:37:07.800 region formed very early on in Bennu's 895 00:37:05.550 --> 00:37:10.050 history and we had thought that this was 896 00:37:07.800 --> 00:37:11.850 actually related to the what we call the 897 00:37:10.050 --> 00:37:13.710 YORP effect that I referred to during 898 00:37:11.850 --> 00:37:15.720 the briefing where interaction with 899 00:37:13.710 --> 00:37:17.910 sunlight and re-radiation of that energy 900 00:37:15.720 --> 00:37:20.190 is heat is causing the asteroid to spin 901 00:37:17.910 --> 00:37:22.230 faster and faster and we thought that 902 00:37:20.190 --> 00:37:24.660 was the driving mechanism for production 903 00:37:22.230 --> 00:37:26.340 of the spinning top shapes so we don't 904 00:37:24.660 --> 00:37:28.350 know the answer right now you can 905 00:37:26.340 --> 00:37:31.620 imagine the science teams are really 906 00:37:28.350 --> 00:37:33.840 busy characterizing the data and really 907 00:37:31.620 --> 00:37:36.210 refining those theories and we are 908 00:37:33.840 --> 00:37:38.910 planning a workshop in November both 909 00:37:36.210 --> 00:37:42.000 sponsored by Hayabusa 2 and osiris-rex 910 00:37:38.910 --> 00:37:43.440 coming together to evaluate exactly that 911 00:37:42.000 --> 00:37:45.330 question what have we learned from these 912 00:37:43.440 --> 00:37:46.710 two great missions and what is their 913 00:37:45.330 --> 00:37:48.960 going to tell us about the formation of 914 00:37:46.710 --> 00:37:51.240 spinning top asteroids and then overall 915 00:37:48.960 --> 00:37:53.330 I would like to acknowledge the great 916 00:37:51.240 --> 00:37:55.650 collaboration that we have with our 917 00:37:53.330 --> 00:37:58.230 colleagues at JAXA and the whole 918 00:37:55.650 --> 00:38:01.050 Hayabusa 2 team it's a really great 919 00:37:58.230 --> 00:38:03.120 relationship and they have successfully 920 00:38:01.050 --> 00:38:05.250 sampled from the surface of Ryugu and 921 00:38:03.120 --> 00:38:07.710 in fact I'm leading a contingent of 922 00:38:05.250 --> 00:38:09.600 osiris-rex team members next month in 923 00:38:07.710 --> 00:38:11.970 April to visit them and get lessons 924 00:38:09.600 --> 00:38:13.530 learned about how we can improve the 925 00:38:11.970 --> 00:38:17.670 chances of success for osiris-rex 926 00:38:13.530 --> 00:38:20.310 sampling next question comes from Jason 927 00:38:17.670 --> 00:38:21.500 Davis of the Planetary Society your line is 928 00:38:20.310 --> 00:38:24.570 open 929 00:38:21.500 --> 00:38:26.610 hi thanks for doing this I just had a 930 00:38:24.570 --> 00:38:28.920 question about you said this was an 931 00:38:26.610 --> 00:38:30.510 active asteroid and I was wondering if 932 00:38:28.920 --> 00:38:32.550 you could just clarify a little bit more 933 00:38:30.510 --> 00:38:35.670 about what that means when you say that 934 00:38:32.550 --> 00:38:38.070 is it that the interior is shifting 935 00:38:35.670 --> 00:38:40.020 around somehow and these dozen or so 936 00:38:38.070 --> 00:38:42.780 that you've seen before and also could 937 00:38:40.020 --> 00:38:46.050 you clarify as it has this ever been 938 00:38:42.780 --> 00:38:47.730 seen before by any spacecraft this type 939 00:38:46.050 --> 00:38:51.119 of particle ejection from an asteroid 940 00:38:47.730 --> 00:38:53.970 or theorized to exist in this type of 941 00:38:51.119 --> 00:38:56.280 asteroid? thanks yeah hi Jason thanks for 942 00:38:53.970 --> 00:38:59.820 that question so active asteroids were 943 00:38:56.280 --> 00:39:02.160 first discovered about 15 years ago when 944 00:38:59.820 --> 00:39:04.710 observers were looking at asteroids in 945 00:39:02.160 --> 00:39:06.720 the main belt that clearly had orbits 946 00:39:04.710 --> 00:39:08.820 that placed him well within that family 947 00:39:06.720 --> 00:39:11.310 of small bodies and then they saw that 948 00:39:08.820 --> 00:39:13.920 they were developing extended coma very 949 00:39:11.310 --> 00:39:16.140 much like comets do and so the original 950 00:39:13.920 --> 00:39:18.600 term that was used was main-belt comets 951 00:39:16.140 --> 00:39:20.730 where we had objects in the main belt 952 00:39:18.600 --> 00:39:22.230 they looked dynamically exactly like 953 00:39:20.730 --> 00:39:24.780 every other asteroid that's out there 954 00:39:22.230 --> 00:39:28.470 yet they were showing periodic activity 955 00:39:24.780 --> 00:39:30.450 and examples of this are Elst-Pizarro 956 00:39:28.470 --> 00:39:32.400 is one I think one of the first ones 957 00:39:30.450 --> 00:39:34.350 that was discovered there have been a 958 00:39:32.400 --> 00:39:37.770 roughly a dozen of them that have been 959 00:39:34.350 --> 00:39:40.260 identified since then all of them are 960 00:39:37.770 --> 00:39:42.330 main-belt asteroids and they have shown 961 00:39:40.260 --> 00:39:44.850 a correlation with perihelion although 962 00:39:42.330 --> 00:39:46.320 that correlation is not perfect and the 963 00:39:44.850 --> 00:39:48.990 thinking was that that these were 964 00:39:46.320 --> 00:39:50.910 probably icy bodies that something 965 00:39:48.990 --> 00:39:53.100 happened an impact had occurred on the 966 00:39:50.910 --> 00:39:55.290 surface and subsurface ice had been 967 00:39:53.100 --> 00:39:57.840 exposed and recently and then was now 968 00:39:55.290 --> 00:40:00.270 just going through cometary activity for 969 00:39:57.840 --> 00:40:02.010 a brief period of time other asteroids 970 00:40:00.270 --> 00:40:04.260 were seen to be undergoing the 971 00:40:02.010 --> 00:40:06.750 rotational acceleration via the YORP 972 00:40:04.260 --> 00:40:08.490 effect like we see on Bennu and some of 973 00:40:06.750 --> 00:40:11.369 that if you take that to the extreme 974 00:40:08.490 --> 00:40:13.470 case the rubble pile on asteroids will 975 00:40:11.369 --> 00:40:15.390 actually fly apart because the angular 976 00:40:13.470 --> 00:40:18.180 momentum that's been added to the 977 00:40:15.390 --> 00:40:19.560 surface overcomes any cohesive forces 978 00:40:18.180 --> 00:40:21.780 that are actually holding the body 979 00:40:19.560 --> 00:40:25.230 together including its own self gravity 980 00:40:21.780 --> 00:40:27.359 so it is a class of asteroids that have 981 00:40:25.230 --> 00:40:29.609 been observed it's a very small number 982 00:40:27.359 --> 00:40:32.010 of them and we think probably multiple 983 00:40:29.609 --> 00:40:33.900 things are happening you can imagine the 984 00:40:32.010 --> 00:40:36.420 commentary kind of activity the YORP 985 00:40:33.900 --> 00:40:38.490 spin up or an impact basically anything 986 00:40:36.420 --> 00:40:41.130 that causes an asteroid to develop a 987 00:40:38.490 --> 00:40:44.400 coma of fine particles around it would 988 00:40:41.130 --> 00:40:45.900 would label it an active asteroid but we 989 00:40:44.400 --> 00:40:47.910 have certainly never seen anything like 990 00:40:45.900 --> 00:40:50.340 this from a spacecraft before you know 991 00:40:47.910 --> 00:40:52.980 we looked at the Eros and Itokawa data 992 00:40:50.340 --> 00:40:54.190 and we talked to our friends on Hayabusa 993 00:40:52.980 --> 00:40:56.530 2 and they're looking 994 00:40:54.190 --> 00:40:58.480 around asteroid you goo none of those 995 00:40:56.530 --> 00:41:00.070 missions have ever detected active 996 00:40:58.480 --> 00:41:02.170 particle injection from an asteroid 997 00:41:00.070 --> 00:41:03.520 surface before so it's a really exciting 998 00:41:02.170 --> 00:41:06.130 opportunity to be able to characterize 999 00:41:03.520 --> 00:41:08.020 and understand the phenomena and decide 1000 00:41:06.130 --> 00:41:09.490 if it is related to what's happening on 1001 00:41:08.020 --> 00:41:11.530 other active asteroids or it's a 1002 00:41:09.490 --> 00:41:13.720 completely unique occurrence 1003 00:41:11.530 --> 00:41:15.490 one thing that makes Bennu very different 1004 00:41:13.720 --> 00:41:17.080 is you wouldn't see this from 1005 00:41:15.490 --> 00:41:19.420 ground-based telescopes it's not a 1006 00:41:17.080 --> 00:41:21.190 massive amount of dust that would show 1007 00:41:19.420 --> 00:41:24.100 up as an extended coma when you're 1008 00:41:21.190 --> 00:41:26.470 looking at it like a comet thank you 1009 00:41:24.100 --> 00:41:30.640 our next question comes from Chance 1010 00:41:26.470 --> 00:41:31.450 Theron New York Times. Hi, thanks so much 1011 00:41:30.640 --> 00:41:33.310 for taking the call 1012 00:41:31.450 --> 00:41:35.950 I was wondering one of the major papers 1013 00:41:33.310 --> 00:41:37.960 says that we think that Bennu's surface 1014 00:41:35.950 --> 00:41:40.780 has changed over the last million years 1015 00:41:37.960 --> 00:41:43.050 do we understand why what process might 1016 00:41:40.780 --> 00:41:45.520 be creating that change 1017 00:41:43.050 --> 00:41:46.660 thank you that's also a great question 1018 00:41:45.520 --> 00:41:48.730 and there looks like there's several 1019 00:41:46.660 --> 00:41:51.520 processes that are going on on Bennu's 1020 00:41:48.730 --> 00:41:53.530 surface right now one of the things 1021 00:41:51.520 --> 00:41:56.050 might be related to this rotational 1022 00:41:53.530 --> 00:41:58.900 acceleration so you can imagine Bennu is 1023 00:41:56.050 --> 00:42:01.270 spinning faster and faster and as the 1024 00:41:58.900 --> 00:42:04.060 rotation rate increases you add angular 1025 00:42:01.270 --> 00:42:05.890 momentum to the surface and that can 1026 00:42:04.060 --> 00:42:08.140 trigger what we would call like a 1027 00:42:05.890 --> 00:42:11.170 landslide or a mass wasting event moving 1028 00:42:08.140 --> 00:42:13.630 material downslope filling in low-lying 1029 00:42:11.170 --> 00:42:15.220 regions of the asteroid we and we do see 1030 00:42:13.630 --> 00:42:17.770 evidence of that happening on the 1031 00:42:15.220 --> 00:42:19.990 surface it does look like large amounts 1032 00:42:17.770 --> 00:42:22.570 of material have moved on the surface 1033 00:42:19.990 --> 00:42:25.540 and are moving down from the polar 1034 00:42:22.570 --> 00:42:27.760 regions towards the equatorial areas so 1035 00:42:25.540 --> 00:42:29.830 we have active geology going on on the 1036 00:42:27.760 --> 00:42:32.140 surface the other thing that we're 1037 00:42:29.830 --> 00:42:33.310 seeing are these particle events and the 1038 00:42:32.140 --> 00:42:36.190 some of the material is completely 1039 00:42:33.310 --> 00:42:38.200 leaving the asteroid but a lot of it is 1040 00:42:36.190 --> 00:42:40.750 actually falling back on to the surface 1041 00:42:38.200 --> 00:42:43.120 and we've only been watching it for a 1042 00:42:40.750 --> 00:42:44.800 few weeks and this might have been going 1043 00:42:43.120 --> 00:42:46.840 on for thousands or hundreds of 1044 00:42:44.800 --> 00:42:49.030 thousands of years so we're still trying 1045 00:42:46.840 --> 00:42:51.430 to understand what kind of resurfacing 1046 00:42:49.030 --> 00:42:53.440 might have taken place as a result of 1047 00:42:51.430 --> 00:42:56.440 these particle ejection and fallback 1048 00:42:53.440 --> 00:42:58.360 events on the surface interesting and do 1049 00:42:56.440 --> 00:43:01.180 you happen to know if the [unintelligible] 1050 00:42:58.360 --> 00:43:05.200 period that lasted helped create the 1051 00:43:01.180 --> 00:43:07.200 spinning top shape or might this activity 1052 00:43:05.200 --> 00:43:09.270 be creating that? 1053 00:43:07.200 --> 00:43:11.849 and well I would say we we thought 1054 00:43:09.270 --> 00:43:14.040 before we arrived that it would be the 1055 00:43:11.849 --> 00:43:15.839 increase in rotation rate that would 1056 00:43:14.040 --> 00:43:17.460 lead to the spinning top shape that was 1057 00:43:15.839 --> 00:43:20.579 the leading theory going into the 1058 00:43:17.460 --> 00:43:21.930 encounter with the asteroid but as with 1059 00:43:20.579 --> 00:43:23.849 all things once you get there and you 1060 00:43:21.930 --> 00:43:25.589 start studying the object itself 1061 00:43:23.849 --> 00:43:27.720 you know that idea starts to get 1062 00:43:25.589 --> 00:43:29.760 questionable and the real reason we're 1063 00:43:27.720 --> 00:43:32.339 questioning that model is because these 1064 00:43:29.760 --> 00:43:35.309 large impact craters which are all over 1065 00:43:32.339 --> 00:43:37.740 the equator of the asteroid and it would 1066 00:43:35.309 --> 00:43:39.869 take a long time we estimate at least a 1067 00:43:37.740 --> 00:43:42.180 hundred million years to a billion years 1068 00:43:39.869 --> 00:43:45.270 in the main asteroid belt to produce 1069 00:43:42.180 --> 00:43:47.069 that crater population so the rotational 1070 00:43:45.270 --> 00:43:49.980 acceleration has got to be a relatively 1071 00:43:47.069 --> 00:43:51.599 new phenomenon because it's so large 1072 00:43:49.980 --> 00:43:53.430 that if it you know been a would have 1073 00:43:51.599 --> 00:43:55.740 had to almost be not rotating at all 1074 00:43:53.430 --> 00:43:57.569 even eight million years ago to see what 1075 00:43:55.740 --> 00:44:00.180 we're seeing right now it probably 1076 00:43:57.569 --> 00:44:01.799 started when Bennu shifted from the main 1077 00:44:00.180 --> 00:44:05.549 asteroid belt into the near-earth 1078 00:44:01.799 --> 00:44:07.049 population so again this is why we 1079 00:44:05.549 --> 00:44:09.750 explore we've learned something 1080 00:44:07.049 --> 00:44:12.750 surprising and it's making us reevaluate 1081 00:44:09.750 --> 00:44:14.910 our understanding of the basic formation 1082 00:44:12.750 --> 00:44:16.859 mechanism of spinning top asteroids and 1083 00:44:14.910 --> 00:44:18.359 we're still we're still getting 1084 00:44:16.859 --> 00:44:20.220 sharpening our pencils and really 1085 00:44:18.359 --> 00:44:22.430 collecting the data before we start to 1086 00:44:20.220 --> 00:44:23.640 zero in on what we think the answer is 1087 00:44:22.430 --> 00:44:25.890 thank you 1088 00:44:23.640 --> 00:44:26.730 our next question comes from Rick Lovett 1089 00:44:25.890 --> 00:44:32.700 freelance 1090 00:44:26.730 --> 00:44:36.089 your line is open thank you yes I have, uh can 1091 00:44:32.700 --> 00:44:39.900 you give me the velocity range of the particles 1092 00:44:36.089 --> 00:44:42.599 being ejected and why don't they all 1093 00:44:39.900 --> 00:44:44.730 either an eject into interplanetary 1094 00:44:42.599 --> 00:44:46.470 space or fall back because it seems like 1095 00:44:44.730 --> 00:44:49.490 you're basically firing bullets out of 1096 00:44:46.470 --> 00:44:52.470 the surface how do they wind up in orbit 1097 00:44:49.490 --> 00:44:54.569 right so we are seeing velocities of the 1098 00:44:52.470 --> 00:44:56.910 particles from just a few centimeters 1099 00:44:54.569 --> 00:44:58.920 per second up to about 3 meters per 1100 00:44:56.910 --> 00:45:02.069 second and the fastest moving particles 1101 00:44:58.920 --> 00:45:04.680 and really you're seeing a whole range 1102 00:45:02.069 --> 00:45:06.720 of velocities there and again remember 1103 00:45:04.680 --> 00:45:08.609 we're still in the process of developing 1104 00:45:06.720 --> 00:45:10.410 the tools and refining those numbers and 1105 00:45:08.609 --> 00:45:11.339 the work that Coralie and her team are 1106 00:45:10.410 --> 00:45:13.740 doing are really contributing 1107 00:45:11.339 --> 00:45:15.400 substantially to that and so we're 1108 00:45:13.740 --> 00:45:17.170 seeing in some cases 1109 00:45:15.400 --> 00:45:19.420 of particles that are being ejected in a 1110 00:45:17.170 --> 00:45:21.579 single event and you're going to have a 1111 00:45:19.420 --> 00:45:23.950 range of velocities some of them are 1112 00:45:21.579 --> 00:45:25.960 moving so fast they leave the asteroid 1113 00:45:23.950 --> 00:45:27.819 some of them are moving so slow they 1114 00:45:25.960 --> 00:45:29.950 basically go up and right back down to 1115 00:45:27.819 --> 00:45:31.720 the surface and then some of them are in 1116 00:45:29.950 --> 00:45:34.089 the sweet spot where there just happened 1117 00:45:31.720 --> 00:45:36.430 to have the right velocity in the right 1118 00:45:34.089 --> 00:45:38.260 direction to be injected into orbit 1119 00:45:36.430 --> 00:45:39.880 around the asteroid and we're still 1120 00:45:38.260 --> 00:45:41.559 trying to understand how long those 1121 00:45:39.880 --> 00:45:43.990 orbits are lasting we have seen at least 1122 00:45:41.559 --> 00:45:46.660 one particle that orbited for about a 1123 00:45:43.990 --> 00:45:49.230 week and then it did fall back down onto 1124 00:45:46.660 --> 00:45:51.130 the surface and we're evaluating other 1125 00:45:49.230 --> 00:45:52.960 groupings of detections 1126 00:45:51.130 --> 00:45:55.450 to see if there's any long-lived orbits 1127 00:45:52.960 --> 00:45:58.329 we do know that it's possible through 1128 00:45:55.450 --> 00:46:00.220 our amazing radio science team they've 1129 00:45:58.329 --> 00:46:02.109 done an analysis of stabilities of 1130 00:46:00.220 --> 00:46:04.720 orbits and there are orbits that could 1131 00:46:02.109 --> 00:46:06.640 last months or years they're very 1132 00:46:04.720 --> 00:46:08.859 special locations so it would just be 1133 00:46:06.640 --> 00:46:11.770 fortuitous if a particle got injected 1134 00:46:08.859 --> 00:46:14.140 right into that regime where it lasted 1135 00:46:11.770 --> 00:46:16.089 for a long time so my prediction right 1136 00:46:14.140 --> 00:46:19.180 now and just as a reminder we're still 1137 00:46:16.089 --> 00:46:20.950 this is new not even a month old in some 1138 00:46:19.180 --> 00:46:23.020 cases data and we're still trying to 1139 00:46:20.950 --> 00:46:24.279 figure out what's going on is that most 1140 00:46:23.020 --> 00:46:26.260 of these are going to be short-lived 1141 00:46:24.279 --> 00:46:30.549 satellites weeks to months and end up 1142 00:46:26.260 --> 00:46:32.140 reimpacting the surface okay thank you one 1143 00:46:30.549 --> 00:46:34.690 other question this is basically for 1144 00:46:32.140 --> 00:46:37.440 NASA where the image is going to be 1145 00:46:34.690 --> 00:46:41.520 located online when I went to that 1146 00:46:37.440 --> 00:46:44.079 website all I got was the press release 1147 00:46:41.520 --> 00:46:47.109 so you're asking about early release 1148 00:46:44.079 --> 00:46:49.690 images I mean ultimately the the images 1149 00:46:47.109 --> 00:46:51.609 will be planetary data system along with 1150 00:46:49.690 --> 00:46:55.690 all the rest of our archived data from 1151 00:46:51.609 --> 00:46:57.250 the Planetary Science Division I'm 1152 00:46:55.690 --> 00:46:59.079 meaning the ones that we're being 1153 00:46:57.250 --> 00:47:02.079 discussed today will we be able to look 1154 00:46:59.079 --> 00:47:04.029 at them so we released we released one 1155 00:47:02.079 --> 00:47:07.299 image of one of the biggest particle 1156 00:47:04.029 --> 00:47:10.270 events and those will be on the asteroid 1157 00:47:07.299 --> 00:47:12.339 mission org website and then we are 1158 00:47:10.270 --> 00:47:14.589 compiling all of the information and 1159 00:47:12.339 --> 00:47:15.849 preparing for publication and I'd like 1160 00:47:14.589 --> 00:47:17.470 to say that's happening sooner rather 1161 00:47:15.849 --> 00:47:19.059 than later but it's a big effort with a 1162 00:47:17.470 --> 00:47:20.410 big team and a lot of people working so 1163 00:47:19.059 --> 00:47:20.849 we're we want to make sure we get it 1164 00:47:20.410 --> 00:47:23.099 right 1165 00:47:20.849 --> 00:47:24.839 when that publication comes out all of 1166 00:47:23.099 --> 00:47:28.369 the data that went into the analysis 1167 00:47:24.839 --> 00:47:30.869 will be available as well okay thank you 1168 00:47:28.369 --> 00:47:35.690 thank you our next question comes from 1169 00:47:30.869 --> 00:47:38.609 Emily Conover science news magazine hi 1170 00:47:35.690 --> 00:47:39.779 so I'm not sure if I missed this but I was 1171 00:47:38.609 --> 00:47:43.979 wondering so for the particles that are 1172 00:47:39.779 --> 00:47:47.029 orbiting how high off of the surface of the 1173 00:47:43.979 --> 00:47:49.859 asteroid are are these things orbiting 1174 00:47:47.029 --> 00:47:51.509 thank you again we're still evaluating 1175 00:47:49.859 --> 00:47:53.249 all of the orbits we certainly have a 1176 00:47:51.509 --> 00:47:54.720 lot more detection than orbital 1177 00:47:53.249 --> 00:47:56.609 solutions at this point and it's a 1178 00:47:54.720 --> 00:47:58.019 tricky problem because not only are we 1179 00:47:56.609 --> 00:48:00.779 dealing with the gravity from the 1180 00:47:58.019 --> 00:48:02.729 asteroid which is very small but because 1181 00:48:00.779 --> 00:48:05.339 of that the radiation pressure from 1182 00:48:02.729 --> 00:48:07.229 sunlight and even thermal radiation from 1183 00:48:05.339 --> 00:48:09.710 the asteroid and from the particle 1184 00:48:07.229 --> 00:48:12.989 itself end up influencing its trajectory 1185 00:48:09.710 --> 00:48:14.819 most of the really I've only seen for 1186 00:48:12.989 --> 00:48:17.279 orbital solutions coming from the team 1187 00:48:14.819 --> 00:48:19.200 so far and maybe Coralie wants to 1188 00:48:17.279 --> 00:48:21.269 comment on this as well most of those 1189 00:48:19.200 --> 00:48:23.430 have been in very low altitudes within 1190 00:48:21.269 --> 00:48:25.920 the range of 100 300 meters from the 1191 00:48:23.430 --> 00:48:28.769 surface we had one that actually got up 1192 00:48:25.920 --> 00:48:30.390 to about 1.2 kilometers from the surface 1193 00:48:28.769 --> 00:48:33.029 right around the range that the 1194 00:48:30.390 --> 00:48:34.799 osiris-rex spacecraft was orbiting and 1195 00:48:33.029 --> 00:48:37.019 so that's kind of the bounds that we have 1196 00:48:34.799 --> 00:48:38.819 so far but again there's a lot more data 1197 00:48:37.019 --> 00:48:41.640 than we've been able to obtain orbital 1198 00:48:38.819 --> 00:48:43.289 solutions for and maybe Coralie do you 1199 00:48:41.640 --> 00:48:46.339 want to speak to how we're going about 1200 00:48:43.289 --> 00:48:51.239 orbit determination on the particles? Uh, 1201 00:48:46.339 --> 00:48:52.769 yeah it takes some identifying particles 1202 00:48:51.239 --> 00:48:54.509 associating them with each other from 1203 00:48:52.769 --> 00:48:59.309 image to image so we're developing 1204 00:48:54.509 --> 00:49:01.950 software toolset to have still have a 1205 00:48:59.309 --> 00:49:06.059 human in the loop but make it easier to 1206 00:49:01.950 --> 00:49:08.160 identify and track those initial some of 1207 00:49:06.059 --> 00:49:10.559 the initial particle ejection events and 1208 00:49:08.160 --> 00:49:12.539 then if we want to get an initial kind 1209 00:49:10.559 --> 00:49:15.660 of prediction for where they were going 1210 00:49:12.539 --> 00:49:19.910 then we go look in more images into the 1211 00:49:15.660 --> 00:49:24.210 future and see if we can observe detect 1212 00:49:19.910 --> 00:49:27.299 more observations of these particles to 1213 00:49:24.210 --> 00:49:30.530 refine their orbits so we're work is 1214 00:49:27.299 --> 00:49:34.120 underway to to build up the toolset and 1215 00:49:30.530 --> 00:49:37.700 and we studied a few particles so far 1216 00:49:34.120 --> 00:49:42.340 our next question comes from Kimberly 1217 00:49:37.700 --> 00:49:45.110 Cartier EOS.org your line is open 1218 00:49:42.340 --> 00:49:47.690 hi thank you for taking my question 1219 00:49:45.110 --> 00:49:49.700 you spoke about the composition of Bennu 1220 00:49:47.690 --> 00:49:52.430 being phyllosilicates and other clay 1221 00:49:49.700 --> 00:49:54.320 minerals how similar is this - some 1222 00:49:52.430 --> 00:49:56.210 meteorites that we've seen fall to earth 1223 00:49:54.320 --> 00:49:59.720 or measure our other asteroids we've 1224 00:49:56.210 --> 00:50:01.790 measured in space thank you that's a 1225 00:49:59.720 --> 00:50:04.700 great question and I can say that we we 1226 00:50:01.790 --> 00:50:07.250 are seeing nice correlations between the 1227 00:50:04.700 --> 00:50:09.290 spectral characteristics of Bennu both 1228 00:50:07.250 --> 00:50:11.030 from the OVIRS visible and infrared 1229 00:50:09.290 --> 00:50:13.700 instrument and from the OTES thermal 1230 00:50:11.030 --> 00:50:17.210 emission spectrometer and they look a 1231 00:50:13.700 --> 00:50:19.190 lot like the rarest most fragile friable 1232 00:50:17.210 --> 00:50:21.740 meteorites in our collections these are 1233 00:50:19.190 --> 00:50:24.710 special types of carbonaceous chondrites 1234 00:50:21.740 --> 00:50:27.140 and we use letters to designate them and 1235 00:50:24.710 --> 00:50:31.010 they look a lot like the CM chondrites 1236 00:50:27.140 --> 00:50:33.230 which are related to a big event in 1237 00:50:31.010 --> 00:50:36.800 Australia where we have most of that 1238 00:50:33.230 --> 00:50:39.620 material in 1969 in Murchison and so 1239 00:50:36.800 --> 00:50:41.720 we're optimistic that we have material 1240 00:50:39.620 --> 00:50:44.840 similar in mineralogy to what we've seen 1241 00:50:41.720 --> 00:50:47.450 in those very organic rich and water 1242 00:50:44.840 --> 00:50:49.250 rich meteorites I will say I'm a 1243 00:50:47.450 --> 00:50:50.990 meteorite scientist by training and 1244 00:50:49.250 --> 00:50:53.510 background and when I look at the rocks 1245 00:50:50.990 --> 00:50:55.580 on the surface of Bennu they don't look 1246 00:50:53.510 --> 00:50:57.500 like those meteorites do in hand samples 1247 00:50:55.580 --> 00:50:59.570 so there's definitely other things going 1248 00:50:57.500 --> 00:51:02.120 on there it's very exciting from that 1249 00:50:59.570 --> 00:51:03.860 perspective so and we're also seeing 1250 00:51:02.120 --> 00:51:05.870 things at meters and tens of meter 1251 00:51:03.860 --> 00:51:08.030 scales that we never had meteorites in 1252 00:51:05.870 --> 00:51:10.130 our collections that look like that but 1253 00:51:08.030 --> 00:51:12.530 I would say spectrally and mineralogically 1254 00:51:10.130 --> 00:51:14.960 they look like they match those rare 1255 00:51:12.530 --> 00:51:16.880 carbonaceous chondrites but the nature of 1256 00:51:14.960 --> 00:51:18.530 the boulders are suggesting there's more 1257 00:51:16.880 --> 00:51:22.010 to the story than what we know from our 1258 00:51:18.530 --> 00:51:25.520 meteorite samples so far thank you 1259 00:51:22.010 --> 00:51:26.710 I'm Ken Kramer Space UpClose your line 1260 00:51:25.520 --> 00:51:29.300 is open 1261 00:51:26.710 --> 00:51:31.520 hi thanks for taking my question and for 1262 00:51:29.300 --> 00:51:34.040 doing this yeah my question is about the 1263 00:51:31.520 --> 00:51:37.010 the compositions actually I wanted to 1264 00:51:34.040 --> 00:51:40.450 know what what do you know about the 1265 00:51:37.010 --> 00:51:42.520 composition of the ejecta particles 1266 00:51:40.450 --> 00:51:45.990 the phyllosilicates what did you expect 1267 00:51:42.520 --> 00:51:48.970 to see that on the surface or not and 1268 00:51:45.990 --> 00:51:52.329 have you seen any any carbon compounds 1269 00:51:48.970 --> 00:51:54.369 at all thank you those are all great 1270 00:51:52.329 --> 00:51:56.230 questions so I'll start with what we 1271 00:51:54.369 --> 00:51:58.630 have seen which are the both the 1272 00:51:56.230 --> 00:52:01.480 phyllosilicates and the iron oxides and 1273 00:51:58.630 --> 00:52:02.829 those are not unexpected those were 1274 00:52:01.480 --> 00:52:05.310 actually kind of the minerals we were 1275 00:52:02.829 --> 00:52:08.050 hoping to see water rich materials 1276 00:52:05.310 --> 00:52:10.329 basically indicating that sometime in 1277 00:52:08.050 --> 00:52:12.609 the ancient past probably very soon 1278 00:52:10.329 --> 00:52:14.349 after the solar system formed in a much 1279 00:52:12.609 --> 00:52:16.660 larger asteroid which we think was 1280 00:52:14.349 --> 00:52:19.060 Bennu's parent there was icy material 1281 00:52:16.660 --> 00:52:22.119 and rocky material that got a little bit 1282 00:52:19.060 --> 00:52:24.520 heated up and the water reacted and 1283 00:52:22.119 --> 00:52:27.430 formed those clay minerals we haven't 1284 00:52:24.520 --> 00:52:31.420 detected the carbon bearing compounds of 1285 00:52:27.430 --> 00:52:33.220 the organic molecules yet we do expect 1286 00:52:31.420 --> 00:52:34.810 that they're there just by similarity 1287 00:52:33.220 --> 00:52:36.700 with the carbonaceous chondrite 1288 00:52:34.810 --> 00:52:39.640 meteorites whenever we have those water 1289 00:52:36.700 --> 00:52:42.430 rich clay minerals they're associated 1290 00:52:39.640 --> 00:52:43.480 with organic material and we think one 1291 00:52:42.430 --> 00:52:44.920 of the reasons we haven't been able to 1292 00:52:43.480 --> 00:52:46.839 detect them is the wavelength range 1293 00:52:44.920 --> 00:52:50.589 where those spectral signatures occur 1294 00:52:46.839 --> 00:52:52.359 are longer wavelengths more heat that's 1295 00:52:50.589 --> 00:52:55.810 coming off the asteroid would make it 1296 00:52:52.359 --> 00:52:58.089 harder to detect that signal and the 1297 00:52:55.810 --> 00:53:00.730 good news is the asteroid is getting 1298 00:52:58.089 --> 00:53:02.740 farther away from the Sun the surface is 1299 00:53:00.730 --> 00:53:04.720 going to be cooling off and by the time 1300 00:53:02.740 --> 00:53:07.210 we get to the mapping station that's 1301 00:53:04.720 --> 00:53:08.740 optimized for the detection of organics we 1302 00:53:07.210 --> 00:53:10.690 expect that the amount of interference 1303 00:53:08.740 --> 00:53:13.930 from the thermal radiation from the 1304 00:53:10.690 --> 00:53:16.119 surface will decrease and then on to 1305 00:53:13.930 --> 00:53:17.890 your question about the particle 1306 00:53:16.119 --> 00:53:19.869 composition we're looking at particles 1307 00:53:17.890 --> 00:53:22.900 that are centimeter to tens of 1308 00:53:19.869 --> 00:53:24.220 centimeters in size and there's hasn't 1309 00:53:22.900 --> 00:53:26.890 been an opportunity to get the 1310 00:53:24.220 --> 00:53:28.690 spectrometers on those to see if we can 1311 00:53:26.890 --> 00:53:30.280 detect them and that's going to be a 1312 00:53:28.690 --> 00:53:32.410 challenging observation because the 1313 00:53:30.280 --> 00:53:34.510 particles occur unexpectedly we can't 1314 00:53:32.410 --> 00:53:36.940 predict when they're going to eject from 1315 00:53:34.510 --> 00:53:38.410 the surface and we can't just be 1316 00:53:36.940 --> 00:53:40.030 scanning all the time in the space 1317 00:53:38.410 --> 00:53:42.819 around the asteroid and hope of catching 1318 00:53:40.030 --> 00:53:44.560 one so it will be fortuitous if we 1319 00:53:42.819 --> 00:53:46.599 actually make a measurement that has 1320 00:53:44.560 --> 00:53:48.190 particles in the spectrometer fields of 1321 00:53:46.599 --> 00:53:51.010 view but that doesn't mean we're not 1322 00:53:48.190 --> 00:53:53.400 going to try in one of the survey 1323 00:53:51.010 --> 00:53:56.980 that are coming up in a few months is 1324 00:53:53.400 --> 00:53:58.720 optimized for looking at plumes and and 1325 00:53:56.980 --> 00:54:01.630 particles being ejected from the surface 1326 00:53:58.720 --> 00:54:03.790 we basically get behind the asteroid so 1327 00:54:01.630 --> 00:54:05.530 we're looking at the night side and the 1328 00:54:03.790 --> 00:54:07.300 limb will be illuminated by the Sun 1329 00:54:05.530 --> 00:54:09.870 which will be on the opposite side of 1330 00:54:07.300 --> 00:54:12.820 the asteroid so if there's dust or gas 1331 00:54:09.870 --> 00:54:14.200 that will be really well seen with the 1332 00:54:12.820 --> 00:54:15.520 cameras because the light will be 1333 00:54:14.200 --> 00:54:17.530 scattered and they'll really show up 1334 00:54:15.520 --> 00:54:19.630 with a nice strong signal and we'll also 1335 00:54:17.530 --> 00:54:21.430 have the spectrometers on to try to 1336 00:54:19.630 --> 00:54:26.890 characterize the plume events in that 1337 00:54:21.430 --> 00:54:30.850 instance thanks there will be no further 1338 00:54:26.890 --> 00:54:32.860 question thank you for participating and 1339 00:54:30.850 --> 00:54:35.490 have a great day this concludes today's 1340 00:54:32.860 --> 00:54:35.490 briefing.