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Ceres --The Dwarf-Water Planet Unique in Our Solar System: NASA Asks "Could It Host Life?"



Ceres, which orbits the Sun in the asteroid belt between Mars and Jupiter, is a unique body in the Solar System, bearing many similarities to Jupiter's moon Europa and Saturn's moon Enceladus, both considered to be potential sources for harboring life. In March of 2015, NASA's Dawn mission will arrive at the dwarf planet Ceres, the first of the smaller class of planets to be discovered and the closest to Earth.

On Thursday, August 15, Britney Schmidt, science team liaison for the Dawn Mission, and Julie Castillo-Rogez, planetary scientist from JPL, spoke in an Google Plus Hangout titled 'Ceres: Icy World Revealed?' about the growing excitement related to the innermost icy body.

"I think of Ceres actually as a game changer in the Solar System," Schmidt said. "Ceres is arguably the only one of its kind."

When Ceres was discovered in 1801, astronomers first classified it as a planet. The massive body traveled between Mars and Jupiter, where scientists had mathematically predicted a planet should lie. Further observations revealed that a number of small bodies littered the region, and Ceres was downgraded to just another asteroid within the asteroid belt. It wasn't until Pluto was classified as a dwarf planet in 2006 that Ceres was upgraded to the same level.

Ceres is the most massive body in the asteroid belt, and larger than some of the icy moons scientists consider ideal for hosting life. It is twice the size of Enceladus, Saturn's geyser-spouting moon that may hide liquid water beneath its surface.

Unlike other asteroids, the Texas-sized Ceres has a perfectly rounded shape that hints toward its origins.

"The fact that Ceres is so round tells us that it almost certainly had to form in the early solar system," Schmidt said. She explained that a later formation would have created a less rounded shape.

The shape of the dwarf planet, combined with its size and total mass, reveal a body of incredibly low density.

"Underneath this dusty, dirty, clay-type surface, we think that Ceres might be icy," Schmidt said. "It could potentially have had an ocean at one point in its history."

"The difference between Ceres and other icy bodies [in the Solar System] is that it's the closest to the Sun," Castillo-Rogez said.

Less than three times as far as Earth from the Sun, Ceres is close enough to feel the warmth of the star, allowing ice to melt and reform. Investigating the interior of the dwarf planet could provide insight into the early solar system, especially locations where water and other volatiles might have existed.

"Ceres is like the gatekeeper to the history of water in the middle solar system," Schmidt said.

As large as Ceres is, its distance has made it a challenge to study from Earth. Images taken by the space-based Hubble Space Telescope provided some insight to its surface, but to be sighted, features could be no larger than 25 kilometers in diameter. Several round circular spots mar the terrain, features which Schmidt said could be any one of a number of geologic terrains, including potentially impact basins or chaos terrains similar to those found on Europa. The largest of these, named Piazzi in honor of the dwarf planet's discoverer, has a diameter of about 250 kilometers. If this feature is an impact basin, it would have been formed by an object approximately 25 km in size.

But for Schmidt, this is another possible indication about the dwarf planet's surface: "It doesn't mean that Ceres hasn't been hit by something bigger than 25 kilometers," she said."It just means that whatever is going on on Ceres has totally erased [the topographic signature of that event]."

Ceres may have suffered major impacts, especially during periods of heavy bombardment early in the Solar System's history. If the surface contained ice, however, those features may have been erased.

"The spectrum is telling you that water has been involved in the creation of materials on the surface," Schmidt said.
The spectrum indicates that water is bound up in the material on the surface of Ceres, forming a clay. Schmidt compared it to the recent talk of minerals found by NASA's Curiosity on the surface of Mars. "[Water is] literally bathing the surface of Ceres," she said.

In addition, astronomers have found evidence of carbonates, minerals that form in a process involving water and heat. Carbonates are often produced by living processes.

The original material formed with Ceres has mixed with impacting material over the last 4.5 billion years, creating what Schmidt calls "this mixture of water-rich materials that we find on habitable planets like the Earth and potentially habitable planets like Mars."

Water is considered a necessary ingredient for the evolution of life as we know it. Planets that may have once contained water, such as Mars, as well as moons that could contain it today, like Enceladus and Europa, are all thought to be ideal for hosting or having once hosted life.

Because of its size and closeness, Schmidt calls Ceres "arguably more interesting than some of these icy satellites."

"If it's icy, it had to have an ocean at some point in time," she said.

Castillo-Rogez compared Earth, Europa, and Ceres, and found that the dwarf planet bore many similarities to Earth, perhaps more than Jupiter's icy moon. Both Earth and Ceres use the Sun as a key heat source, while Europa takes its heat from its tidal interaction with Jupiter. In addition, the surface temperature of the dwarf planet averages 130 to 200 degrees Kelvin, compared to Earth's 300 K, while Europa is a frosty 50 to 110 K.

"At least at the equator where the surface is warmer, Ceres could have preserved a liquid of sorts," Castillo-Rogez said.

Liquid water could exist at other points on the dwarf planet known as cold traps, shadowed areas where frozen water could remain on the surface. Such icy puddles have been found on Earth's moon.

"The chemistry, thermal activity, the heat source, and the prospect for convection within the ice shell are the key ones that make us think that Ceres could have been habitable at least at some point in its history," Castillo-Rogez said.

As scientists develop more information about Europa and Enceladus, there has been a greater call to investigate the two prime sites for life. But Schmidt and Castillo-Rogez think that Ceres could also be a great boon for astrobiology and space exploration.

"It's not a difficult environment to investigate," she said."As we think about the future of landed missions for people and rovers, why not go to Ceres?"

Though it would be more challenging to drill into than Europa, which boasts an icy surface layer, the dwarf planet would make a great site to rove around on. Schmidt also noted that it could make a great launching point when it comes to reaching the outer solar system. Its smaller mass would make it easier to land on--and leave--than Mars, which could make it a good site for manned missions.

"We have such a big planet bias, we have such a bias for things that look exactly like us," Schmidt said.

"In this kind of special place in the Solar System, we have a very unique object that might be telling us a lot about what we don't know about building a habitable planet."

NASA's Dawn mission launched September 27, 2007. It traveled to the asteroid Vesta, where it remained in orbit from July 2011 to July 2012 before heading to Ceres. It is slated to spend five months studying the dwarf planet, though Schmidt expressed hope that the craft would continue working beyond the nominal mission, allowing the team to study the icy body even longer.

Castillo-Rogez pointed out that not only will Dawn reach Ceres in 2015, the European Space Agency's Rosetta spacecraft will be escorting the comet Churyumov-Gerasimenko around the Sun that year, while NASA's New Horizons mission will be reaching Pluto and its moon Charon.

"'15 is going to be a great year for icy bodies," Castillo-Rogez said.

"I think when we get to Ceres, it's just going to be an absolute game changer, a new window into the Solar System that we wouldn't have without going there," Schmidt said

The Daily Galaxy via Nola Taylor Redd/NASA Astrobiology Magazine


How about getting to work and outfit Ceres with giant Solar Sails and crash it into Mars. Toss in a few odd comets and the red planet isn't quite as parched. Terraforming writ large.

we`re not even capable to move a small asteroid, no use thinking about a planet On the other hand, if we will be able to move asteroids, they will be good enough to warm Mars.

Interesting thought "farticustheelder" posted above, about crashing Ceres into Mars.

I'd like to see that played out in a sci-fi movie on the big screen, in 3D!

However, in reality, I think we might end up just destroying 2 worlds, perhaps?

I suspect crashing an object as large as Ceres into Mars would have the power to turn 30 to 50 percent of Mars' surface into a molten mess for a long time.

The Mars sky would also fill with dust and debris for a long time.

The impact would almost certainly and permanently alter Mars' spin rate, and axis tilt in some way.

Wouldn't it even send shock waves and large fractures on the opposite side of Mars?

Also, not sure what would happen to all the water thrown out in that impact?

There would probably be some rain/precipitation following the impact... but all the extra water might simply drain and find it's way down below the crust of Mars, in the new giant hole/crater/fracture formed at the point of impact?


Rather than crashing Ceres into Mars, a better way might be to simply and gently export Ceres water to Mars.

Ceres low gravity would make it relatively "easy" for a semi automated robotic factory to send water into space, using a space-elevator on Ceres.

Because of Ceres low gravity, we actually already have the materials/technology today, to build a space elevator on Ceres.

Once in space, the blocks of water-ice would simply be "flung" on an intercept path towards Mars, were it could be captured into Mars orbit, and then brought down to Mars.

You wouldn't even need much energy to "fling" blocks of ice to Mars. Just a gentle boost is all it would take.

Of course, if you fling them "lightly and gently" without putting too much energy into it, it would then take a while to arrive at Mars.

But once the first block of ice to arrives at Mars, there would be a steady non-stop stream of blocks of ice.

Essentially it would become a river in space, flowing from one planet to another!

In fact if we find that the ice-ocean-moon known as Europa is devoid of life, then we could export it's ocean over to Mars.

I heard Europa may have as much water as Earth's oceans, so that alone would be more than enough for Mars, most likely.

Again, you could just fling the ocean from Europa to Mars, one block at a time.

Europa is in a deep gravity well, gotta be too expensive to export water from there. But a slow capture of Ceres' water would need a space waterfall. Split the difference, speed up mountain sized chunks, if sized properly, might melt/vaporize during impact. At Mars' surface temperature it might quite a while to melt Ceres gently delivered.

The importance of Ceres is remarkable. 18 months seems like such a long time to wait for this.

On Ceres a space elevator would work with existing materials. It is the largest such body. Because of this sending things from Ceres to almost anywhere above its equator would be zero cost as long as you didn't care how long it took. You could throw ice cubes at the Earth every nine hours.

Cannot wait to see what Ceres secrets are revealed.

It would be a long time before we could create a "space river", simply because first we must study Ceres to kind if there's ANY trace of life in there. If there is, we can't just "steal" the water from there.
And another problem: what's the point of bringing water to Mars, when Mars lost most of the water it had? It will probably loose water again.

I agree with Stefan. Mars' lower mass caused the core to cool long ago. When the core was no longer molten the magnetosphere ceased to exist. This allowed radiation from the sun to carry away much of the atmosphere, and subsequently, much of the surface water. Reintroducing more water won't do any good unless we can "jump start" the magnetosphere.

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