Ceres, More Fresh Water Than Earth!?, From Space.com Options

[tedstryk]

Unfortunately, I'm pretty sure this animation is *not* a series of Hubble images, but rather a simulation based on a surface map based on Hubble images.  So its of no use.  You need to get the original images to work with.

If this was done like previous sets for targets that appear so small, the 200 images are probably sets of 50 at each of the four viewpoints shown in the image released possibly using different filters (but not always) and almost certainly multiple views at some or all wavelengths for a super-resolution effect. So the only way to make a movie would be to do what they did, or to make a four image animated gif, which could be done with what we have.

[Decepticon]

I can't believe the length of this mission.


Hardware failure possibilities goes up the longer the mission. What happens if something bad happens a week before Dawn arrives (*Knock On Wood*)??

[Marz]

I must say I found this article to be quite an eye-opener. I always thought of 'roids as boring lumps of rock, not this interesting! I wish ESA could launch a Ceres Express!

[tedstryk]

I can't believe the length of this mission.
Hardware failure possibilities goes up the longer the mission. What happens if something bad happens a week before Dawn arrives (*Knock On Wood*)??

The good thing that may come from this, according to what I have read, is that there may be multiple flybys of smaller asteroids along the way and in between the main targets.

[JRehling]

  Perhaps MER and Cassini will keep going long enough to keep me from getting bored.  Ideally I'd like these missions to overlap enough that there will always be images coming back from some corner of the Solar System!

There are currently three orbiters at Mars with one more cruising there now. In the meantime, Messenger will have flybys and a main mission returning images from much of the period between now and 2011, and Venus Express will have its mission in the meantime. Who knows how long Mars Smart Lander will last? And New Horizons will provide a quick flyby of the jovian system in 2007 before getting to Pluto in 2015. The Moon is sure to get still more attention (SMART is there now) from multiple countries by 2015. And a few small body missions are on the way.

Cassini may last decades, trumping all of this with a vast set of targets that will provide many discovery opportunities before we would become bored with the saturnian system.

The MERs won't last forever (moving parts are hell), but if left to stand and collect sunlight, with the occasional serendipitous cleaning event, they could last indefinitely, although their use will taper off if they lose mobility before something else gets them.

[edstrick]

I'm wondering...

If Ceres is differentiated into a rocky core and water-ice mantle with a dirt-layer on top...

Since it's closer to the sun, it's warmer inside than Callisto. Temperature is relatively high since the dirt is black.

The water ice, protected from 4 1/2 billion years of sunlight <more or less> by thickness and a dirt-layer, may be pretty damn soft, especially if small amounts of salts are present, leached out of the rock as it differentiated.

Ceres may not preserve craters ... even with low isotope heating and heat flow from inside, the ice may be so warm and soft that even in the low gravity, it just flows, turning craters into palimpsests, like craters on Enceladus, Ganymede and Callisto are relaxed. Very very interesting....

[SigurRosFan]

Back in August 2003:

--- Ceres apparently retains considerable volatile material. The latest gross properties indicate that Ceres has a density of about 2100 kilograms per cubic meter, suggesting that the body's composition may be half water (). Its density is similar to that of Ganymede (1940 kg/m3) and Callisto (1860 kg/m3). ---

http://www-ssc.igpp.ucla.edu/dawn/newslett..._evolution.html

[David]

Juno is by far the smallest and the most irregular of the first four asteroids.

Was it pure happenstance that Juno was the third asteroid discovered? It's only the thirteenth or fourteenth largest Main Belt asteroid, it's not particularly bright, and I can't really see that there's anything remarkable about it; why was it discovered before. say, Hebe, Iris, or Hygiea?

[SigurRosFan]

This article shows a limb profile.

HST Mapping of the Shape and Rotation Pole of Ceres

http://www-ssc.igpp.ucla.edu/dawn/newslett...df/20040831.pdf

[Decepticon]

Great Links Everyone! I'm also looking forward to next earth telescopes that will become operational over the next 10yrs. That way Ceres mapping will improve and help with the dawn mission.

I really do hope Ceres has more in common with the Jupiter moons.

[AndyG]

One big advantage of Ceres is that the opportunity for getting there repeats every 15.5 months - more often than Mars. Meanwhile the Hohmann flight time is about 470 days - not seriously worse than Mars. Indeed, it's almost weird that the asteroids haven't been better covered by missions before the ion-age. After all, it's still bright out there - a couple of hundred watts per square metre - and the low local gravities mean that multiple targets becomes an attractive option. Or is it all too O'Neillian? Finding accessible and potentially useful resources just a few thousand m/s of delta-V from cislunar space?

Andy G

[antoniseb]

One big advantage of Ceres is that the opportunity for getting there repeats every 15.5 months

I agree that it is strange that we haven't already made more missions to these places, but hey, we've only launched a few probes per year that escape Earth orbit, and that seems to be the budget. What an interesting coincidence that this giant water resource is already named after the Earth goddess.

[David]

One big advantage of Ceres is that the opportunity for getting there repeats every 15.5 months - more often than Mars. Meanwhile the Hohmann flight time is about 470 days - not seriously worse than Mars.

Huh. So as late as 2011 or 2012 we could launch a "Ceres Express" probe, and it would get to Ceres before DAWN?

[Bob Shaw]

Huh. So as late as 2011 or 2012 we could launch a "Ceres Express" probe, and it would get to Ceres before DAWN? 

David:

True, but... ...half the story.

Firstly, 'Ceres Express' wouldn't visit Vesta as well. Secondly, it might not be able to orbit Ceres except at great expense in terms of launch mass. And thirdly, it ain't funded!

Have a look at the attached trajectory diagram - in effect, Dawn carries out two missions for the price of one - and orbit insertion around two mini-planets, as well!

The asteroid size comparisons are also fascinating! These are *worlds*!

Bob Shaw

Attached thumbnail(s)

 

[David]

The asteroid size comparisons are also fascinating! These are *worlds*!

It's funny that at about the same time we find ourselves talking about how small Pluto is, and how big Ceres is.