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The Bright Stuff:New Dawn Findings at Ceres

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[Nathan Stein, Doctoral Researcher, Caltech]

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When folks think about asteroids

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they might think about dead chunks of rock

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that are floating around space.

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And what we see with Ceres is that

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the processes are modifying the surface

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even in the present day.

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[Jennifer Scully, JPL Research Scientist]

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Approaching Ceres,

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we saw this very bright region on the surface.

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And then as we got closer and closer,

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you saw that there were multiple bright regions

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in this one crater.

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There's the one in the center,

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which is called Cerealia Facula,

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and then there's the ones off to the side in the crater floor,

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which are called Vinalia Faculae.

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Cerealia is located in a pit within the center of the crater.

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That pit is about 10 kilometers wide.

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And so it's about 1/9 the diameter of

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Occator Crater itself.

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And within that pit there is a little central dome.

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[Stein] What we're seeing is an indication that

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there are liquid brines

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potentially in the subsurface, even in the present day

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rising to the surface and becoming these bright spots.

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And that tells us that there has to be a process

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providing energy to drive these fluids to the surface.

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We call them bright spots, but actually it's a relative term.

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The brightest bright spot on Ceres, Cerealia Facula,

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has an albedo of around .5

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which is about the same brightness as dirty snow.

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Bright spots on Ceres aren't limited to a single place.

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We've found that there are over 300 bright spots,

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all over the surface of Ceres.

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And that indicates that this is a relatively widespread process.

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[Scully] The salts that we see in Occator Crater

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are of similar composition to salts that we find

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In Mono Lake in California.

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It's interesting that you can have these similar materials

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found in different places.

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that were formed by different processes.

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[Stein] Ceres represents something of a bridge

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between the bodies of the inner solar system

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and the outer solar system

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In the inner solar system, we see rocky bodies.

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In the outer solar system, we, more broadly, see icy bodies.

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And Ceres is sitting somewhere in-between.

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But we know now from the bright spots that it is changing.

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The bright spots that are already on the surface

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are darkening over time scales of

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hundreds of millions of years or even less.

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And we also see that the bright spots maybe are still forming.

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So Ceres is still an active body.

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And we still have a lot of questions about

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what are the processes that are modifying

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Ceres' surface over time

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and what that tells us about the internal nature of Ceres

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and how it actually formed.