If Ceres does in fact
have as much water as the Earth, then we have a natural impactor for Venus able
to deliver sufficient water to cool down the hot surface rocks and begin the
oxidation processes that makes life viable.
Even better there may be enough water to saturate the crust itself
fairly quickly and promote the beginnings of plate tectonics.
I do not think though
that we would have to wait for geological time to allow us to use the
planet. The water would almost
immediately absorb the latent heat in the atmosphere and in the process provide
the torrential rain needed to strip heat from the surface crocks
themselves. At least everything would
fall below water’s boiling point quickly including the upper layers of rock.
Once that has happened,
locales near the poles will open up upon which landings can be established and
a base built. Ongoing steaming will
continue to dump heat back into the atmosphere continuously for a long time and
that heat will then be dumped into space or possibly absorbed chemically as
well. The oceans will be long lasting
hot pots for a long time.
We are at least going
to know for sure in early 2015.
Water Detected on
Dwarf Planet Ceres
Jan. 22, 2014: Scientists using the Herschel space observatory have made the first definitive detection of water vapor on the largest and roundest object in the asteroid belt, dwarf planet Ceres.
"This is the first time water vapor has
been unequivocally detected on Ceres or any other object in the asteroid belt
and provides proof that Ceres has an icy surface and an atmosphere," said
Michael Küppers of ESA in Spain, lead author of a paper in the journal Nature.
Herschel is a European Space Agency (ESA)
mission with important NASA contributions. Data from the infrared observatory
suggest that plumes of water vapor shoot up from Ceres when portions of its icy
surface warm slightly.
The results come at the right time for NASA's
Dawn mission, which is on its way to Ceres now after spending more than a year
orbiting the large asteroid Vesta. Dawn is scheduled to arrive at Ceres in the
spring of 2015, where it will take the closest look ever at its surface.
"We've got a spacecraft on the way to
Ceres, so we don't have to wait long before getting more context on this
intriguing result, right from the source itself," said Carol Raymond, the
deputy principal investigator for Dawn at NASA's Jet Propulsion Laboratory in
Pasadena, Calif. "Dawn will map the geology and chemistry of the surface
in high resolution, revealing the processes that drive the outgassing
activity."
For the last century, Ceres was known as the
largest asteroid in our solar system. But in 2006, the International
Astronomical Union, the governing organization responsible for naming planetary
objects, reclassified Ceres as a dwarf planet because of its large size. It is
roughly 590 miles (950 kilometers) in diameter. When it first was spotted in
1801, astronomers thought it was a planet orbiting between Mars and Jupiter.
Later, other cosmic bodies with similar orbits were found, marking the
discovery of our solar system's main belt of asteroids.
Scientists believe Ceres contains rock in its
interior with a thick mantle of ice
that, if melted, would amount to more fresh water than is present on all of
Earth. The materials making up Ceres likely date from the first few million
years of our solar system's existence and accumulated before the planets
formed.
This graph shows variability in the intensity of
the water absorption signal detected at Ceres.
Until now, ice had been theorized to exist on
Ceres but had not been detected conclusively. It took Herschel's far-infrared
vision to see, finally, a clear spectral signature of the water vapor. But
Herschel did not see water vapor every time it looked. While the telescope
spied water vapor four different times, on one occasion there was no signature.
Here is what scientists think is happening: when
Ceres swings through the part of its orbit that is closer to the sun, a portion
of its icy surface becomes warm enough to cause water vapor to escape in plumes
at a rate of about 6 kilograms (13 pounds) per second. When Ceres is in the
colder part of its orbit, no water escapes.
The strength of the signal also varied over
hours, weeks and months, because of the water vapor plumes rotating in and out
of Herschel's views as the object spun on its axis. This enabled the scientists
to localize the source of water to two darker spots on the surface of Ceres,
previously seen by NASA's Hubble Space Telescope and ground-based telescopes.
The dark spots might be more likely to outgas because dark material warms
faster than light material. When the Dawn spacecraft arrives at Ceres, it will
be able to investigate these features.
Credits:
More
information:
This research is part of the Measurements of 11
Asteroids and Comets Using Herschel (MACH-11) program, which used Herschel to
look at small bodies that have been or will be visited by spacecraft, including
the targets of NASA's previous Deep Impact mission and upcoming Origins
Spectral Interpretation Resource Identification Security Regolith Explorer
(OSIRIS-Rex). Laurence O' Rourke of the European Space Agency is the principal
investigator of the MACH-11 program.
Herschel is a European Space Agency mission,
with science instruments provided by consortia of European institutes and with
important participation by NASA. While the observatory stopped making science
observations in April 2013, after running out of liquid coolant, as expected,
scientists continue to analyze its data. NASA's Herschel Project Office is
based at JPL. JPL contributed mission-enabling technology for two of Herschel's
three science instruments. The NASA Herschel Science Center, part of the
Infrared Processing and Analysis Center at the California Institute of
Technology in Pasadena, supports the U.S. astronomical community.
Dawn's mission is managed by JPL for NASA's
Science Mission Directorate in Washington. Dawn is a project of the
directorate's Discovery Program, managed by NASA's Marshall Space Flight Center
in Huntsville, Ala. UCLA is responsible for overall Dawn mission science.
Orbital Sciences Corp. in Dulles, Va., designed and built the spacecraft. The
German Aerospace Center, the Max Planck Institute for Solar System Research,
the Italian Space Agency and the Italian National Astrophysical Institute are
international partners on the mission team. Caltech manages JPL for NASA.
Dwarf Planet Ceres – 'A
Game Changer in the Solar System'
http://www.astrobio.net/exclusive/5648/dwarf-planet-ceres-%E2%80%93-a-game-changer-in-the-solar-system
of
the smaller class of planets to be discovered and the closest to Earth. 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.
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 PlusHangout 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."
The innermost icy body
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.
"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.
Studying
the surface
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.
Telescopes
on Earth have also been able to study the light reflecting from the planet and
read its spectra.
"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."
A prime site for life?
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.
The
future of Ceres
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
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