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Planetary RadioDecember 5, 2018

Last Week, Mars. This week, An Asteroid Called Bennu.

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On This Episode
Bruce Banerdt head shot
Bruce Banerdt

Principal Research Scientist and InSight Mission Principal Investigator

Jason Davis thumbnail
Jason Davis

Editorial Director, The Planetary Society

Bruce Betts Head Shot 2015
Bruce Betts

Chief Scientist / LightSail Program Manager, The Planetary Society

Mat Kaplan
Mat Kaplan

Planetary Radio Host and Producer, The Planetary Society

The InSight lander has only just arrived on Mars. Now, OSIRIS REx has reached asteroid Bennu after traveling through deep space for a year and a half. We’ll talk with the Planetary Society’s Jason Davis about this mission that will bring a sample of Bennu back to Earth after it has learned all it can over the next 19 months. We’ll also hear from the young student who gave the asteroid its name. Then we’ll return to the Red Planet for a conversation with the leader of the InSight mission, Bruce Banerdt. We’ve got very special prizes for this week’s What’s Up space trivia contest.

Artist's concept of OSIRIS-REx


Artist's concept of OSIRIS-REx

NASA/Goddard/University of Arizona

This image of asteroid Bennu was taken by the OSIRIS-REx spacecraft from a distance of around 80 km (50 miles).

OSIRIS-REx's approach to Bennu


OSIRIS-REx's approach to Bennu
This video shows the OSIRIS-REx spacecraft’s view of Bennu during the final phase of its journey to the asteroid. From 17 August through 27 November, the spacecraft’s PolyCam camera imaged Bennu almost daily as the spacecraft covered the remaining 2.2 million kilometers toward the asteroid. The final images were obtained from a distance of about 65 km kilometers. During this period, OSIRIS-REx completed four maneuvers slowing the spacecraft’s velocity from approximately 491 m/s to 0.04 m/s relative to Bennu, which resulted in the slower approach speed at the end of the video.

Trivia Contest

This Week’s Prizes:
The beautiful second edition of the National Geographic Space Atlas: Mapping the Universe and Beyond AND the new National Geographic Almanac 2019. Also a Planetary Radio t-shirt from the Planetary Society Chop Shop store and a 200-point astronomy account.

This week's question:

What spacecraft was intended to visit comet 46P/Wirtanen?

To submit your answer:

Complete the contest entry form at or write to us at no later than Wednesday, December 12th at 8am Pacific Time. Be sure to include your name and mailing address.

Last week's question:

What did the InSight lander and some warriors from the Middle Ages have in common?


The answer will be revealed next week.

Question from the November 21 space trivia contest question:

What chemical elements were named after celestial bodies or the gods or goddesses for whom the bodies were named?


There are nine elements named after celestial bodies: Cerium, Helium, Mercury, Neptunium, Palladium, Plutonium, Selenium, Tellurium and Uranium. (Sorry, Krypton.)

Listen more: solar system formation, mission status, podcasts and videos, astronomy by planetary missions, asteroids, OSIRIS-REx, Planetary Radio, explaining technology, pics of hardware on earth, explaining science, asteroid 101955 Bennu, explaining image processing

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