Planetary Radio • Nov 25, 2014

2014: The Year We Landed on a Comet

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On This Episode

20141125 Mark Mc Caughrean thumbnail

Mark McCaughrean

Senior Science Advisor for European Space Agency Directorate of Science and Robotic Exploration

Not just landed. Orbited, too. European Space Agency Senior Science Advisor Mark McCaughrean helps us celebrate the Rosetta orbiter and the Philae lander. Emily Lakdawalla prepares for the end of another spectacular ESA mission: Venus Express. Casey Dreier fills in for Bill Nye with news of two upcoming space events in Washington D.C. Another listener will win observing time from iTelescope on this week’s What’s Up segment with Bruce Betts and Mat Kaplan.

OSIRIS sees Philae multiple times during landing
OSIRIS sees Philae multiple times during landing The sharp-eyed OSIRIS camera on the Rosetta orbiter snapped numerous images of Philae as it descended toward its touchdown on the comet on November 12 at 15:34 UTC. Images documented the spacecraft rotating, and also saw evidence of the lander's touchdown on the comet surface. One final image, captured 9 minutes after the landing, sees the spacecraft bright against the shadowed surface, heading to the east on its first bounce.Image: ESA / Rosetta / DLR / MPS for OSIRIS Team MPS / UPD / LAM / IAA / SSO / INTA / UPM / DASP / IDA

This week's question:

What are the TWO active region numbers assigned to the giant sunspot that was visible during the most recent partial solar eclipse. The second number was assigned when the region reappeared as the Sun rotated.

To submit your answer:

Complete the contest entry form at or write to us at [email protected] no later than Tuesday, December 2, at 8am Pacific Time. Be sure to include your name and mailing address.

Last week's question:

What is the approximate mass of the Philae lander? Hint: It’s more than an ant.


The answer will be revealed next week.

Question from the week before:

When did the French Guiana Space Centre become operational?


The French Guiana Space Center became operational in 1968.