1 00:00:00,040 --> 00:00:04,070 Well it may not feel like it this week in parts of the country, but today marks 2 00:00:04,070 --> 00:00:08,120 the first day of Spring. This is the spring equinox and here to tell us 3 00:00:08,120 --> 00:00:12,200 what a equinox is and else we can expect this year is Dr. Alex Young 4 00:00:12,200 --> 00:00:16,320 at NASA Goddard Space Flight Center. (Dr. Young) Thanks for having me. 5 00:00:16,320 --> 00:00:20,510 (reporter) So start by telling us what is exactly is an equinox? 6 00:00:20,510 --> 00:00:24,700 (Dr. Young) Well the Earth orbits the Sun spinning at a tilt and so sometimes 7 00:00:24,700 --> 00:00:28,740 twice a year that tilt is actually like this. Meaning that the north 8 00:00:28,740 --> 00:00:32,780 and south hemispheres get equal illumination from the 9 00:00:32,780 --> 00:00:36,820 sun. So that's the Spring and Fall equinox's. 10 00:00:36,820 --> 00:00:40,880 So today in the Northern Hemisphere we are experiencing 11 00:00:40,880 --> 00:00:45,070 the Spring equinox or the beginning of astronomical spring. 12 00:00:45,070 --> 00:00:49,160 (reporter) Now there is another exciting event happening this year 13 00:00:49,160 --> 00:00:53,200 a total solar eclipse. When is this happening and what can we expect? 14 00:00:53,200 --> 00:00:57,220 (Dr. Young) Well on August 21st the entire Northern American continent 15 00:00:57,220 --> 00:01:01,350 will get to experience a solar eclipse, where the moon 16 00:01:01,350 --> 00:01:05,400 moves in front of the Sun, casting a shadow down on the Earth, and those 17 00:01:05,400 --> 00:01:09,590 in special area called the path of totality about 18 00:01:09,590 --> 00:01:13,720 70 miles wide. From Oregon down to South Carolina 19 00:01:13,720 --> 00:01:17,750 will experience the total solar eclipse. Where the disc of the Sun is 20 00:01:17,750 --> 00:01:21,800 blocked out completely by the moon, allowing us to see it's very 21 00:01:21,800 --> 00:01:25,870 dim faint outer atmosphere, called the corona, something we 22 00:01:25,870 --> 00:01:30,000 normally can't see invisible light on the ground, we can only see that 23 00:01:30,000 --> 00:01:34,190 from space. But a total solar eclipse is special opportunity for us. 24 00:01:34,190 --> 00:01:38,370 (reporter) Now NASA will be doing some pretty cool science during the eclipse 25 00:01:38,370 --> 00:01:42,420 Talk about how NASA is using the eclipse to study 26 00:01:42,420 --> 00:01:46,490 the Sun and Earth. (Dr. Young) Well we're excited to study 27 00:01:46,490 --> 00:01:50,620 the corona, and that's what we can see during a total solar eclipse 28 00:01:50,620 --> 00:01:54,800 So it's an opportunity from the ground to it in incredible detail, to 29 00:01:54,800 --> 00:01:58,950 test out instruments that we would normally fly at some point in space. 30 00:01:58,950 --> 00:02:02,980 and test them on the ground. We can also experience the effects of 31 00:02:02,980 --> 00:02:07,020 the change in temperature and light, as that shadow passes across the Earth. 32 00:02:07,020 --> 00:02:11,090 Which has an impact on our atmosphere as well as the plants and animals around 33 00:02:11,090 --> 00:02:15,200 We are looking at this corona from a distance, but in 34 00:02:15,200 --> 00:02:19,400 2018 we are going to send a spacecraft "solar probe plus" 35 00:02:19,400 --> 00:02:23,580 to fly through that part of the atmosphere that part we're seeing 36 00:02:23,580 --> 00:02:27,630 during the eclipse, and for the first time actually touch a star. 37 00:02:27,630 --> 00:02:31,670 (reporter) Talk about how eclipses help us find 38 00:02:31,670 --> 00:02:35,740 planets orbiting other stars? (Dr. Young) Well the eclipse is a special kind of 39 00:02:35,740 --> 00:02:39,890 event that is called a transit, where a moon or a planet 40 00:02:39,890 --> 00:02:44,080 moves in front of a star. When we look at distant stars 41 00:02:44,080 --> 00:02:48,280 we can see the light dimming from that star and the amount 42 00:02:48,280 --> 00:02:52,330 of dimming is actually an indicator of how big the object moving 43 00:02:52,330 --> 00:02:56,380 in front of it is. This is how we find exo-planets in other 44 00:02:56,380 --> 00:03:00,500 solar systems. So we the TESS spacecraft coming up which is going to give us 45 00:03:00,500 --> 00:03:04,660 a survey of all these exo-planets, and then allows us 46 00:03:04,660 --> 00:03:08,840 to eventually use the James Webb Space Telescope to look at the atmospheres 47 00:03:08,840 --> 00:03:12,860 of these planets to look for signs of life 48 00:03:12,860 --> 00:03:16,930 in the rest of the Universe. 49 00:03:16,930 --> 00:03:21,000 (reporter) Very exciting. Where can we learn more, especially about the up coming eclipse? 50 00:03:21,000 --> 00:03:25,130 (Dr. Young) Well if you go to eclipse2017.nasa.gov 51 00:03:25,130 --> 00:03:29,330 you can find out the eclipse, you can get lots of imagery and videos, activities 52 00:03:29,330 --> 00:03:33,470 as well as finding out about safety, how to view it in person 53 00:03:33,470 --> 00:03:37,500 and how to view it on line. 54 00:03:37,500 --> 00:03:40,704 (reporter) Great thanks so much. (Dr. Young) Thank you.