The Kepler countdown proceeds and, naturally, will preoccupy many of us during the day. I won’t try to keep up with the minutiae, as we’re not set up to be a news site at that level of granularity. Go instead to the Kennedy Space Center’s countdown page, where you’ll find live video feeds, or the Kepler portal. You can track the Kepler feed on Twitter here, although it’s been quiet all morning. The launch is scheduled for 10:49 EST (03:49 UTC) and the clock, as they say, is running. NASA TV should kick in about two hours before launch.
If you want a Kepler diversion, try Astrobiology Magazine‘s story on Ceres as a possible source for life on Earth. What’s not to like about yet another candidate for life in the outer Solar System? Even so, this one seems to be quite a stretch.
The story focuses on a theory from Joop Houtkooper (University of Giessen), who sees the ‘dwarf planet’ (I think that’s the right IAU terminology these days) as a potentially living world, a place a bit like Europa, although lacking the immense tidal force exposure that makes the latter so interesting. You may remember Houtkooper as the man who claimed that the Viking landers found life on Mars. In that controversial 2006 work, he re-examined old data from the Viking gas exchange experiment (GEx) and speculated on life-forms using hydrogen peroxide.
Image: A Hubble image of Ceres. Could the tiny object once have held life? Could it still? Credit: NASA, ESA, J. Parker/SWRI, P. Thomas/Cornell, L. McFadden/Univ. of Maryland.
As to Ceres, the scientist notes that the total volume of water on the tiny object is much greater than can be found in all the oceans of the Earth. “[I]f life is not unique to the Earth and could exist elsewhere, then these icy bodies are the places where life may have originated,” says Houtkooper, who points to the survival of Ceres’ water during the Late Heavy Bombardment, when asteroid impacts wreaked havoc on our own planet. From the story:
If there was life on Earth before this dangerous era, it was most likely eradicated and had to begin again after much of this cosmic debris had cleared out of the inner solar system. Interestingly, evidence indicates that Ceres avoided being pummeled by devastating impacts during this time. If it had been bombarded, it would have completely and forever lost its water mantle, as its gravitational force is too weak to recapture it. This is probably what happened to the asteroid Vesta, which has a very large impact crater and no water.
So we may be looking at an ocean of liquid water under the ice, a small place with a rocky core that could have the kind of hydrothermal vents that produce primitive organisms. In that case, an ancient survivor of catastrophe could have, through rocks blown off its surface that drifted to Earth, become the source of renewed life here. Let’s hope the DAWN mission can tell us more. It reaches Ceres in 2015, at which point we’ll learn whether, like Enceladus, Ceres may suddenly swim into focus as a potential home for living organisms.
Not to pick nits, but what possible power source could there be on Ceres for hydrothermal vents? There are no significant tidal forces, and it’s too small for radiosotope-driven heating.
Doug M.
Doug, I don’t think this is nit-picking at all. The lack of a power source looks to me to be the greatest problem with the idea that Ceres might have life.
Well, it seems like the default model for Ceres would be icy shell -> “mantle” of cold sterile water under pressure -> rocky core.
We can hope it will be more complicated than that — the Solar System has thrown us a lot of surprises — but I have trouble seeing how it could have any sort of active “geology”.
Doug M.
Doug and Paul, the following paper from 2005, (reference #46 on Wikpedia’s page on Ceres), suggests that radiosotope driven heating is quite possible, and an ocean is possible as well:
http://adsabs.harvard.edu/abs/2005JGRE..11005009M
Also see this 2007 version by the same authors (reference #54 on the Ceres wikipedia page):
http://www.lpi.usra.edu/meetings/lpsc2007/pdf/2006.pdf
and finally, just for fun, see this 2007 paper:
http://www.spaceblogger.com/reports/Ceres_As_An_Abode_Of_Life_999.html
Good catch re the McCord/Sotin paper. I see that they talk about a water content between 17% and 27% by mass.
It sounds like Ceres could be an interesting hybrid of Mars and Europa. Certainly much more interesting than Vesta.
Hi Folks;
The interesting about Ceres, being that it is so small, is that a core should be drillable to its very center given the appropriate technologies. My thinking is that the gravity of Ceres is low enough to permit deep drilling to depths at which temperate temperatures exist where perhaps life could be discovered.
It is starting to seem like the number of locations within just our solar system alone where life could exist is starting to abound.
With all of the robotic planetary missions planned or being considered over the next few decades, my guess is that planetary geologists and exobiologists are going to have one heck of a field day. This should also spur the National and Global manned interstellar travel efforts on to develop concrete plans to send humans to other star systems.
Thanks;
Jim
If the “Ceres as an abode for life” link doesn’t work for you, here is an alternative:
http://www.spacedaily.com/reports/Ceres_As_An_Abode_Of_Life_999.html
It is by the always interesting and sometimes controversial Bruce Moomaw.
Neptune’s moon Triton definitely has geysers and Pluto is also
expected to have them, which would mean at least underground
lakes of liquid water if not an entire ocean:
https://centauri-dreams.org/?p=1360
So if they can this, yes keeping in mind that they have other
bodies around them to create tidal forces, perhaps Ceres is
more than just a “dwarf planet” (I do not like that term).
On this 30th anniversary of Voyager 1’s flyby of the Jovian system
and its discovery of a very volcanic Io and a mysteriously different
Europa, let us keep our minds open to new possibilities when it
comes to the unknown in space.
http://gishbar.blogspot.com/2009/03/30th-anniversary-of-voyager-1-flyby-of.html
While I am here: Any speculations on what that big white spot
is in the HST image of Ceres?
See the image above and here:
http://www.universetoday.com/2009/03/05/life-on-ceres-could-the-dwarf-planet-be-the-root-of-panspermia/
If I’m reading those papers right, they’re saying “Ceres might have kept enough heat to have a still-liquid ocean below its surface”, not “Ceres has kept enough heat to be geologically active”. Am I wrong?
Doug M.
Doug, I know very little with respect to geology, but I assume the issue here isn’t whether not Ceres is geologically active but rather whether or not of hydrothermal vents could exist in a hypothetical ocean within Ceres. My understanding until today was that to get a hydrothermal vent, you just need water above, heat below, and cracks in the rock for the water to seep in and get heated up. I figured that must be quite oversimplified(!), so I’m so slowly tackling this paper:
Hydrothermal Systems in Small Ocean Planets
by Steve Vance, Jelte Harnmeijer, Jun Kimura, Hauke Hussmann, Brian deMartin, J. Michael Brown. Astrobiology. December 2007
The paper is here: http://earthweb.ess.washington.edu/~svance/WebPresentations/Vance2007.pdf
and the paper is also cached here so you can read it on the web in html:
http://74.125.95.132/search?q=cache:LwAJf99fEVYJ:earthweb.ess.washington.edu/~svance/WebPresentations/Vance2007.pdf
Paul, I hope you won’t mind if I quote the abstract:
We examine means for driving hydrothermal activity in extraterrestrial oceans on planets and satellites of less than one Earth mass, with implications for sustaining a low level of biological activity over geological timescales. Assuming ocean planets have olivine-dominated lithospheres, a model for cooling-induced thermal cracking shows how variation in planet size and internal thermal energy may drive variation in the dominant type of hydrothermal system—for example, high or low temperature system or chemically driven system. As radiogenic heating diminishes over time, progressive exposure of new rock continues to the current epoch. Where fluid-rock interactions propagate slowly into a deep brittle layer, thermal energy from serpentinization may be the primary cause of hydrothermal activity in small ocean planets. We show that the time-varying hydrostatic head of a tidally forced ice shell may drive hydrothermal fluid flow through the seafloor, which can generate moderate but potentially important heat through viscous interaction with the matrix of porous seafloor rock. Considering all presently known potential ocean planets—Mars, a number of icy satellites, Pluto, and other trans-neptunian objects—and applying Earth-like material properties and cooling rates, we find depths of circulation are more than an order of magnitude greater than in Earth. In Europa and Enceladus, tidal flexing may drive hydrothermal circulation and, in Europa, may generate heat on the same order as present-day radiogenic heat flux at Earth’s surface. In all objects, progressive serpentinization generates heat on a globally averaged basis at a fraction of a percent of present-day radiogenic heating and hydrogen is produced at rates between 10^9 and 10^10 molecules cm 2 s 1.
I have no problem with speculating about life occurring elsewhere, or talking about real experiments that look at these possibilities. However, the notion of panspermia or exogenesis (life being transferred to earth) is science fiction to the extreme; not even future science fact.
I think the idea that Ceres may be a site for life is far more interesting and exciting and significant than the notion that life may have evolved elsewhere first and was then brought to Earth. We can examine Ceres and gather empirical evidence regarding life on Ceres. I do not see how we can gather empirical evidence or conduct robust experiments regarding Panspermia or exogenesis as the origin of life on Earth.
-Zen Blade
Have to agree with Zen Blade about the dearth of hard facts regarding Panspermia. The Russians are planning to sent hardy microbes to Mars and back as part of their Phobos mission in a few years, but if the microbes survive, all that will prove is that *Earth* life can survive such a trip. If that’s true and we subsequently find life on other planets and moons in our solar system, unless it’s radically different than Earth life (meaning it couldn’t survive on Earth either now or in Earth’s past environments) then Earth has to be suspect as to its origin.
As for Ceres and other icy bodies, they could be great refueling stations for space vehicles traveling the outer regions. Potable water, hydrogen and oxygen are ours for the taking using relatively simple technologies to create them.
Putting aside the possibility of life, Ceres is a very interesting body in its own right. It is the most accessible planetoid in a pristine state, left over from the formation of our solar system and, as such, is categorically different from the rest of the Asteroid belt.
If we are looking for a site for manned exploration after Mars, Ceres now looks to be the obvious target.
Hi All
An alternative view is that the case for ice on Ceres is over-stated…
Is Ceres Differentiated?
Zolotov, M. Y.
American Geophysical Union, Fall Meeting 2008, abstract #P51C-1424
Abstract
The dwarf planet Ceres is the largest body in the asteroid belt, and has a density of 2.0-2.3 g/cm3, and a dark non-icy surface with signs of hydrated minerals [1-3]. As opposed to a differentiated internal structure with a nonporous rocky core and a water ice mantle [1-3], there are arguments for a slightly differentiated or undifferentiated porous interior with a mineral composition similar to CI/CM carbonaceous chondrites. Ceres’ shape and dimensions reported in [3] may imply a slightly differentiated or even undifferentiated interior. Ceres’ internal pressures (< ~150 MPa) are insufficient to significantly reduce porosity and microporosity of accreted chondritic materials. Thus, there is no need for abundant ice to be present to account for the density of Ceres. An existence of a rocky layer atop a water mantle is unfavorable owing to gravitational instability [1]. Observed hydrated surface materials are not consistent with the unaltered nature of the rocky layer modeled in [1]. If such a layer sunk into the water mantle, subsequent sublimation of an icy shell would have led to abundant surface salt deposits, which are not observed. Later accumulation of a layer of hydrated minerals at the surface may not be consistent with the ice-bearing surfaces of such bodies as Callisto, and with cosmic dust accumulation rates on inner solar system bodies. Therefore, the surface material could represent hydrated planetesimals from which Ceres accreted, and/or reflects in situ aqueous alteration, which is less likely. Ceres could have formed from pervasively aqueously processed low-density asteroids (largely C- and G-types) in which 26Al had largely decayed. Abundant water ice may not have been accreted. The weak heat from 40K and 232Th decay would not have caused mineral dehydration and density stratification of the interior [1]. However, evaporation of limited aqueous solutions and warm ice sublimation caused water redistribution in the porous interior, some re-condensation and escape to space. Corresponding formation of light-toned salts may account for Ceres’ elevated albedo compared to carbonaceous chondrites [cf. 1]. It is also possible that Ceres and spectrally similar asteroids are rich in low-density C-H-O-N species compared to CI/CM chondrites, which are depleted in them compared to comets.
Refs.:
[1] McCord T.B., Sotin C. (2005) J. Geophys. Res. 110, E05009.
[2] Thomas P.C. et al. (2005) Nature 437, 224-226.
[3] Carry B. et al. (2008) Astron. Astrophys. 478, 235-244.
And, of course, there’s the idea that the small bodies might be warmed by primordial black-holes as well as the usual sources of heat.
Ceres appears to be an abandoned Imperial Death Star. The white spot is the large concave disc containing the planet-destroying superlaser, now filled with cometary debris after millions of years of neglect.
Careful when approaching; though nothing living could have survived the eons since the station was last active (when it was used to pulverize the rebel stronghold planet formerly orbiting between Mars and Jupiter) there may be residual defense systems lying dormant, waiting to awaken and strike at hapless space probes that pass too closely.
Mark, you think this is funny?
Well, considering level of wishful thinking displayed by many comments and even may posts here…
A non-icy composition for Ceres would make it less anomalous when considered along with the compositions of the other asteroids.
Andy, good point.
Adam, thank you for the alternative view.
On the other hand, I saw a very speculative article suggesting that if Ceres does have a differentiated icy composition, that could be xplained if it was formed in the Kuiper Belt:
blogs.discovery.com/cosmic_ray/2008/07/an-escapee-from.html
Goldstein Hovercraft, thanks for posting the link re “Hydrothermal Systems in Small Ocean Planets,” an interesting source I hadn’t encountered before.
How about Ceres as a giant radio telescope:
http://www.opennasa.com/2009/03/08/the-benac-orbit-keplers-follow-on/
The Benac Orbit, Kepler’s Follow On
Once Kepler finds the other Earths, it time to listen to their radio stations!
So here is the next big thing: Craters as huge satellite dishes for antenna feeds orbiting above them.
Think Arecibo, but a bagillion times bigger, and instead of that little white thing hanging on cables with winches you have a satellite flying above the dish.
Ceres, you big ball of radio wave reflective ice and rock, this is what you–and your equatorial craters–were made for! Orbital parameters copy write. (But if you must know: http://www.twitter.com/johnbenac)
September 13, 2009
Craters on Vesta and Ceres Could Show Jupiter’s Age
Written by Nancy Atkinson
Scientists use crater distributions to tell the ages of planetary surfaces on rocky bodies. But how can the ages of gas planets be determined? Believe it or not, possibly from craters.
Scientists from the National Institute of Astrophysics in Rome say that crater patterns on the two largest asteroids in the asteroid belt, Vesta and Ceres, could help pinpoint when Jupiter began to form during the evolution of the early Solar System.
Their study modeling the cratering history of the two asteroids – which are believed to be among the oldest in the Solar System — indicates that the type and distribution of craters would show marked changes at different stages of Jupiter’s development.
The study explored the hypothesis that one of the asteroids, or perhaps both objects, formed at the same time as Jupiter, and that studying their cratering histories could provide information about the birth of the giant planet.
Full article here:
http://www.universetoday.com/2009/09/13/craters-on-vesta-and-ceres-could-show-jupiters-age/
Images of planetoid 2 Pallas from HST here:
http://nasawatch.com/archives/2009/10/smd-is-sitting.html