1 00:00:00,634 --> 00:00:04,504 In late 2018, as NASA’s OSIRIS-REx spacecraft neared its 2 00:00:04,504 --> 00:00:08,609 target, Bennu, the asteroid grew in detail from a few tiny pixels 3 00:00:08,609 --> 00:00:12,646 to an incredibly hi-resolution image. OSIRIS-REx confirmed the 4 00:00:12,646 --> 00:00:16,283 asteroid’s basic shape, which was originally observed in 1999 5 00:00:16,283 --> 00:00:19,887 by ground-based radar at Arecibo Observatory. What scientists 6 00:00:19,887 --> 00:00:23,490 didn’t expect was just how rough and boulder-filled the asteroid 7 00:00:23,490 --> 00:00:26,393 would turn out to be. While it can be difficult to fully grasp 8 00:00:26,393 --> 00:00:29,796 Bennu’s unfamiliar surface, it’s helpful to understand the scale 9 00:00:29,796 --> 00:00:32,566 of what you’re seeing here. In this image, the brightest 10 00:00:32,566 --> 00:00:35,903 boulder is the length of a horse and the large boulder in this 11 00:00:35,903 --> 00:00:39,473 image is the width of a soccer field. Another challenge for the 12 00:00:39,473 --> 00:00:42,876 mission is the asteroid’s small size and weak gravity. This 13 00:00:42,876 --> 00:00:45,746 means that OSIRIS-REx needs to fly daringly close to the 14 00:00:45,746 --> 00:00:49,950 surface in order to enter into orbit. With its orbital A phase, 15 00:00:49,950 --> 00:00:53,086 OSIRIS-REx successfully entered the closest-ever orbit for a 16 00:00:53,086 --> 00:00:56,857 spacecraft, setting a Guinness World Record in the process. 17 00:00:56,857 --> 00:01:00,027 Then, 6 months later, it beat its own record during its 18 00:01:00,027 --> 00:01:03,297 orbital B phase and approached to within a few hundred meters 19 00:01:03,297 --> 00:01:07,134 of the rocky surface. Because OSIRIS-REx flew so closely over 20 00:01:07,134 --> 00:01:10,103 the surface during orbital B, the team was able to map the 21 00:01:10,103 --> 00:01:13,173 topography and shape of Bennu better than we have our own 22 00:01:13,173 --> 00:01:16,710 Moon. In addition to mapping Bennu, OSIRIS-REx plans to 23 00:01:16,710 --> 00:01:19,680 collect and return a sample of the asteroid back to Earth. To 24 00:01:19,680 --> 00:01:22,983 do that, the spacecraft will carefully tag the surface of 25 00:01:22,983 --> 00:01:26,920 Bennu. The OSIRIS-REx team has selected four possible sample 26 00:01:26,920 --> 00:01:31,925 sites for the mission: Osprey, Kingfisher, Nightingale, and 27 00:01:31,925 --> 00:01:36,363 Sandpiper. The spacecraft has been closely imaging these sites 28 00:01:36,363 --> 00:01:40,133 from different angles to select the best touch-down spot for 29 00:01:40,133 --> 00:01:42,970 OSIRIS-REx. What was originally envisioned as a smooth and easy 30 00:01:42,970 --> 00:01:46,673 touchdown on Bennu’s surface, has become a complex endeavor to 31 00:01:46,673 --> 00:01:50,811 tag a small, crowded space on the asteroid – an area no larger 32 00:01:50,811 --> 00:01:56,083 than a few parking spots, by mid 2020. The OSIRIS-REx team has 33 00:01:56,083 --> 00:01:59,252 already pushed the boundaries of scientific exploration, going 34 00:01:59,252 --> 00:02:02,122 from ground-based radar images all the way to being a few 35 00:02:02,122 --> 00:02:05,892 hundred meters from the asteroid surface, and is now mere months 36 00:02:05,892 --> 00:02:07,694 away from a sample collection attempt.