Well if you wanted to send a message to people in a solar system, you could put something on a moon like this. Once they were advanced enough to find it, they would probably understand it.
So a 'complex crater' involves a certain degree of subsidence of the uplifted outer rim, and the forces involved in this subsidence, spreading the underlying rock, combine at the center to push material upwards into a small solitary peak. I always assumed this happened due to a continuous pressure of magma or something in volcanoes, but it turns out the effect happens regardless of and in addition to any underlying geothermal activity: it's a feature of gravity and long-term settling of annular structures.
It looks like this is a crater which has ice(water ice? CO2 ice?) underlying a thick, mobile dust layer. When Ceres suffered an impact at some point in the past, it excavated a crater in the ice and dust, then the dust settled back down, covering everything. Over the following millennia / eons, the crater rim subsided and the center entered a long period of slow uplift, pushing through the dust layer and exposing the ice.
It's possible something more novel could be at work here involving phase changes and maybe cyclical patterns; Unpredicted seasonal geysers have been observed on Mars, as an example. A complex crater filled with dust over underlying ice, though, is probably the default assumption.
Abandoned, but fully operational, alien base. We send humans there, land successfully, discover we are not alone in the Universe, and Humanity is united behind the effort to gain deeper understanding of ourselves. Also, there's a hidden door somewhere in the base that leads deeper into the interior of Ceres, where we discover .. the whole thing was a station.
In Alastair Reynold's scifi novel Pushing Ice, it wasn't Ceres, but another body in our solar system that with an apparent origin similar to what you've imagined...and behavior just too interesting for the curious primates to ignore...
Link it with the recent mysterious high altitude dust clouds on Mars and it could be the prelude to something exciting or downright nasty, if you read as much science fiction as I do.
If so it would be some sort of ice volcano. I didn't find where it said what the spectrum was for the camera, infra-red? visible? something else? One theory for it is that it is a dust covered ice ball, a large enough impact could uncover the ice (although I would expect there to me a sublimation cloud at that point.)
If the core is nickle iron it could be a chunk that melted and reformed after impact.
Or it could be a bad pixel :-) but that seems unlikely as it moves with Ceres and not with Dawn.
A recursive portal into the far, far distant future; billions of years in fact. Once entered, there would be no way back for physical bodies, however, radio transmissions could find a way.
Ceres is as old as Earth, so its Uranium should be as lowly enriched in U-235 as here, which is today too low for natural reactions. Additionally it would be highly unusual for Ceres to have concentrated Uranium ore deposits to a similar degree as Earth, for mineralogical reasons.
My crazy theory: you think it was a coincidence that, just as our spacecraft approaches Ceres, a defense satellite in Low Earth orbit 'mysteriously' explodes? Pah! That's just what they want you to think!
I'm curious too, so I was glad to read that the probe will get about 10x closer, and of course being there permanently means there should be some benefit from cumulative observations until such time as the power/equipement runs down.
Edit: it's entertaining to think about what results would create a scramble for a follow-up mission to exploit it.
As mentioned in some of the comments to the posted article, I want to know if getting some spectroscopy on those white spots couldn't be possible. Perhaps summed over a quite long series? (Wouldn't it be a thrill if they were metallic?)
According to the comment by Marc Rayman "We have obtained visible and infrared spectra every time we have acquired images. The results are not ready for release."
I don't think you'd get much from a spectrum. It's all (likely) reflected sunlight. It's not emitting light, so there are no emission lines, and it's not absorbing light, since there's no atmosphere.
The lack of atmosphere actually helps, as the spectroscopy will be more accurate.
I would guess that it's a very reflective crystalline structure. You can see that as the bright structure goes beyond the terminator, it is still visible for a frame, but it completely disappears the frame after. It's hard to say either way though as we don't know the specs of the camera. Lots of materials reflect light differently at wavelengths outside our normal vision.
> Dawn will not come this close to its permanent partner again for six weeks. Well before then, it will be taken firmly and forever into Ceres’ gentle gravitational hold.
<3 For some reason I love this excerpt. It humanizes the scientific voyage.
It would be the most amazing thing if another spot would turn on on the other side of the center one :)