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Planetary RadioJanuary 19, 2016

Marc Rayman’s Dawn Mission Update

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On This Episode
Marc Rayman head shot
Marc Rayman

Dawn Chief Engineer and Mission Director, Jet Propulsion Laboratory

The Dawn Mission Chief Engineer Marc Rayman returns for another report on the ion-engine powered mission, now orbiting 240 miles above dwarf planet Ceres in the Asteroid Belt. Emily Lakdawalla explains the bittersweet quality of Cassini’s latest images of Saturn’s moons. Bill Nye talks about two more milestones in commercial space access. Mat and Bruce offer an ISS Above system in the new space trivia contest.

Ceres (animation)

NASA / JPL-Caltech / UCLA / MPS / DLR / IDA

Ceres (animation)
These animations of Ceres rotating and a flyover of Occator crater are from photos Dawn took in its second mapping orbit at an altitude of 2,700 miles (4,400 kilometers). The false colors are used to highlight very subtle differences in color that your eye generally would not discern but which reveal differences in the nature of the material on the ground. As explained below, the bright areas tend to be slightly blue. Full animation and caption.

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Trivia Contest

This week's prize is an amazing ISS-Above HD system from ImageBEAM Inc. Also, a Planetary Radio t-shirt, if you ask nicely.

This week's question:

On plaques carried by the Pioneer 10 and 11 probes, Earth’s position in shown in relation to 14 what?

To submit your answer:

Complete the contest entry form at or write to us at no later than Tuesday, January 26th at 8am Pacific Time. Be sure to include your name and mailing address.

Last week's question:

What and when was the first spacecraft flyby of a comet?


The answer will be revealed next week.

Question from the week before:

Hydrogen and helium are the most abundant elements in the Milky Way galaxy. What comes in a distant third by mass fraction?


Oxygen is the third most abundant element in the Milky Way galaxy.

Listen more: Enceladus, Cassini, Titan, Saturn's irregular moons, Dawn, Saturn's moons, asteroid 1 Ceres, Saturn's rings, Commercial spaceflight, mission status, asteroids, Planetary Radio, Bill Nye

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