Enceladus Focus Group

There is a new discussion group focusing specifically on Saturn's moon Enceladus, where the discovery of water vapour geysers erupting from underground reservoirs was recently announced (see also the Features column on the right side of the blog). There will be an EncFG meeting at Caltech in Pasadena, California on October 8, 2006, plus an official special session on Enceladus titled "Enceladus: Water, Warmth, Organics... and Life?" at the American Geophysical Union (AGU) fall meeting in San Francisco (December 11-15, 2006). The original introductory message is below:

Following on the recent Cassini discoveries of geysers, organics, and excess heat emanating from the south polar terrain of Enceladus, and the exciting implications of these findings for possible subterranean chambers of liquid water, we are forming an Enceladus Focus group to begin a community-wide conversation about this fascinating moon.

The goal is to provide a forum devoted to the dissemination and in-depth discussion of recent Enceladus observations, and their bearing on the interior/thermal structure and history, geologic history, chemistry, geyser mechanisms, and other physical properties and processes, all with an eye towards examining Enceladus as a body of astrobiological interest and a target for future planetary exploration.

This group will also consider the questions:

What future observations should be made with Cassini in its extended mission that would be useful for astrobiological investigations?

What should be the goals and mission scenarios of future robotic exploration of Enceladus?

If you are interested in being a part of this discussion, please send an email to

majordomo@ciclops.org

with the following in the body of the email:

subscribe EnceladusFocus

This will put you on an email list, which is the first step. If there is sufficient interest, the plan would be to hold our inaugural meeting at the upcoming October DPS meeting.

We hope you join us.

Carolyn Porco, CICLOPS/Space Science Institute, Boulder, CO
Chris McKay, NASA Ames Research Center, Moffett Field, CA

Moon-Mars Anagram

An amazing bit of wordplay, this was in a desk calendar I have:

"That's one small step for a man, one giant leap for mankind." - Neil A. Armstrong

becomes...

A thin man ran, makes a large stride, left planet, pins flag on Moon! On to Mars!

Bright Material in Tyrrhena Terra

© NASA/JPL/ASU

Extensive deposits of very bright material in this new Mars Odyssey image released July 28, 2006. More sulfate deposits, similar to those found by Opportunity and Spirit? Ice?

Caves on Titan?

© ESA

An interesting article in New Scientist, regarding the possiblity of caves or caverns on Titan. As a world with methane rains, rivers, lakes and giant sand dunes already discovered, why not caves also?

Interestingly, when the Huygens probe landed on Titan in 2005, the descent images showed some odd-looking possible "hollows or pits" in the hills along the "shoreline" near the landing site (above image); the original context image is here. Caverns or other erosional features from the methane rains and winds?

Methane Rain on Titan

First the discovery of the hydrocarbon (methane / ethane) lakes, and now further confirmation that it also rains liquid methane on Titan, ranging from ongoing drizzles to larger storms.

More information:

www.nature.com/nature/journal/v442/n7101/edsumm/e060727-06.html
planetary.org/blog/article/00000658
tinyurl.com/lzouo
tinyurl.com/s4shx

Cassini Finds Lakes on Titan's Arctic Region

Further information on the lakes of Titan, in this Cassini-Huygens news release.

Cassini Finds Hydrocarbon Lakes on Titan

© NASA/JPL

It seems that the long-sought hydrocarbon lakes on Titan may have finally been found, near the moon's north pole. Scattered across the terrain as seen in the new radar images, they were found during Cassini's 16th flyby of Titan on July 21. A similar, single lake-like feature had been seen previously by Cassini near the south pole. As compared to those on Earth, they would be liquid methane or ethane, due to Titan's very cold surface temperatures.

More information:

www.planetary.org/news/2006/0724_Cassini_RADAR_Reveals_Lakes_on_Titan_At.html
www.space.com/scienceastronomy/ap_060725_titan_lakes.html
www.newscientistspace.com/article/dn9612-titan-may-be-a-land-of-lakes-after-all.html
www.astronomy.com/asy/default.aspx?c=a&id=4420
sciencenow.sciencemag.org/cgi/content/full/2006/725/1
tinyurl.com/lg3ra

Cassini's Search for Lakes Continues

© NASA/JPL

From the Cassini-Huygens web site:

After revealing a land of mountains and river channels near Titan's equator in April, Cassini's radar will illuminate the high northern reaches of Titan during the next flyby on July 21, 2006 (July 22 UTC). In winter's shadow since the arrival of Cassini in 2004, Titan's northern terrain could harbor methane lakes, which shrink in summer and expand in winter.

Images and further information should be available soon.

Titan's Xanadu Region is Remarkably Earth-Like

© NASA/JPL

The latest radar images from the Cassini spacecraft of Saturn's moon Titan continue to reveal a remarkably Earth-like, albeit colder, world, with diverse geology including hills, valleys, sand dunes and (methane) rivers as well as possible methane lakes. The newly released images, of the large continent-like Xanadu region, were taken on April 30, 2006. Image highlights are also available here:

photojournal.jpl.nasa.gov/catalog/PIA08604
photojournal.jpl.nasa.gov/catalog/PIA08552
photojournal.jpl.nasa.gov/catalog/PIA08605

More information:

www.planetary.org/blog/article/00000649

Ongoing Titan radar images are also catalogued here:

www.planetary.org/explore/topics/saturn/titan_radar.html
pirlwww.lpl.arizona.edu/~perry/RADAR

Defrosting Sand Dunes at Martian North Pole

© NASA/JPL/Malin Space Science Systems

From the MSSS web site:

This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows a portion of a sand dune field in the north polar region of Mars. The dunes are covered with frozen carbon dioxide which accumulated over the autumn and winter months in the northern hemisphere. During the spring, the time at which this image was acquired, the carbon dioxide begins to sublime away, going directly from solid to gas, just as dry ice does here on Earth. The dark spots, streaked by blowing winds, may be places where the frost has been removed (exposing underlying dark sand), places where the grain size or roughness of the frost has increased (increasing shadowing due to the change in texture), or both.

Exploring Mars with Mini-Probes

© Gus Frederick

At MIT, researchers are testing a new way of exploring Mars - thousands of small, baseball-sized probes which could cover vast areas of the planet. They would be a novel way of investigating interesting but rougher terrain, such as canyons and caves, which would be more difficult for rovers to navigate.

More information:

robots.mit.edu/projects/microbots/index.html
www.newscientistspace.com/article/dn9610-spherical-microrobots-could-explore-mars.html
www.cosmosmagazine.com/node/468

Mars Rovers Still Going After 900 Days

The Spirit and Opportunity rovers are continuing to far outlive initial expectations as to how long they would survive on Mars. Both are now approaching the 1,000 days mark (after a warranty for only 90 days!), and aside from a few glitches, are still functioning well and in good health.

New Insights Into Origin and Makeup of Comets

© NASA/JPL

Results from Deep Impact and Stardust continue to give scientists a better understanding of what comets are made of and their origins, including the surprising finding of carbonates and clays in Tempel 1, the first time seen in any comet studied so far.

Flying Over the Cloudy World

© ESA/MPS, Katlenburg-Lindau, Germany

The Venus Express spacecraft continues its studies of the dynamic atmosphere of Venus, including the huge double-vortex over the south pole and other intriguing features.

More information:

www.newscientistspace.com/article/dn9538-venuss-double-vortex-mystery-deepens.html

Spirit Rover Finds Calcium Sulfate on Mars

In a significant new finding relating to past water on Mars, the Spirit rover has now found calcium sulfate.

According to Steve Squyres in quoted portions of this update from The Planetary Society (June 30, 2006):

At Gusev Crater, Spirit uncovered two more meteorites while working its winter campaign at Low Ridge, near McCool Hill in the Columbia Hills. Even more intriguing, the rover found calcium sulfates in the target Halley, "That's a significant recent finding, and it was a real surprise," said Steve Squyres, rover principal investigator, of Cornell University, in an interview yesterday. It is, in essence, yet another clue that water flowed there in the past.

"The latest thing we've gotten on Halley is that along with the hematite and the high zinc [content], it also seems to have a significant quantity of calcium sulfates in it." The discovery marks the first time Spirit has found calcium in all its work around Gusev. The substantial amount of calcium sulfate with zinc and hematite are "things that would plausibly point toward some form of aqueous alteration," Squyres expounded. "The thing that's interesting is that we haven't really seen calcium sulfates before at the Gusev site. We've seen magnesium sulfates in places and certainly very powerful concentrations of ferric sulfates, but calcium sulfate is something new."

'Starshade' Could Help Find Other Earth-Like Planets

A giant "starshade" space shield, used with an orbiting telescope, could be used to help find other Earth-like planets in other solar systems, and even identify features such as oceans, continents, polar caps, cloud banks and biomarkers like methane, oxygen and water, according to a new study at the University of Colorado at Boulder.

To date, over 150 planets have been found in other solar systems so far, using other techniques, primarily larger worlds ranging from about Neptune-size to ones larger than Jupiter. As new search methods are used and improved, Earth-size or even smaller planets are expected to be found in the near future.

More information:

www.nature.com/nature/journal/v442/n7098/edsumm/e060706-01.html
www.space.com/scienceastronomy/060705_space_shield.html

Alien Rain?

© Dr. Godfrey Louis (Mahatma Gandhi University)


© Cardiff University

While not a planetary exploration-related subject per se, the recent "red rain" debate is certainly interesting, and if a panspermia origin was to be verified, would be an important finding in terms of possible planetary or even inter-planetary biology (the theory being that simple microsopic life forms could be found in comets and "seeding" any planets that they happen to collide with).

The "red rain" which appeared over Kerala, India in 2001, has been postulated by some scientists as possible evidence of such alien microbial cells (the original scientific team led by Dr. Godfrey Louis at Mahatma Gandhi University in India in particular, who first studied the samples), although there is certainly no consensus on this, and much controversy and debate. The rainwater had been coloured red by an unknown material immediately after a witnessed "airburst" in the area (possible cometary or meteorite impact in the upper atmosphere?). Dust, pollen, algae, unknown microbes, etc. were all possibilities.

As of this writing, further studies are finally being conducted by two additional research teams, at Cardiff and Sheffield universities in the UK. So far, these new studies have reportedly confirmed that the "cells" really are still-unidentified biological cells, with thick cell walls and "daughter cells" (evidence of reproduction?). Louis' team had reported finding no DNA in the cells, which would be very unusual, as all known earthly cells do, except for red blood cells. The two other UK teams have tentatively identified DNA in the samples however, but this is not confirmed yet. The additional findings have also ruled out blood cells as the answer however, despite a superficial resemblance. The cells also reportedly have been observed reproducing at high temperatures. Further details are expected to be published later this year.

Below is a summarized list of related articles and findings to date, including from Dr. Godfrey Louis (Mahatma Gandhi University), Cardiff University, New Scientist, Astronomy, Popular Science, astronomer David Darling and others. See also the print issues of New Scientist (March 4-10, 2006) and Popular Science (June, 2006).

www.newscientist.com/contents/issue/2541.html
www.newscientistspace.com/article/mg19025453.100-red-rain-puzzle-is-still-up-in-the-air.html
www.newscientist.com/data/av/podcast/newsci-20060303-raining-aliens.mp3 (MP3)
www.astronomy.com/asy/default.aspx?c=a&id=4337
www.popsci.com/popsci/science/2c21c0f98d07b010vgnvcm1000004eecbccdrcrd.html
www.daviddarling.info/encyclopedia/R/red_rain_of_Kerala.html
www.astrobiology.cf.ac.uk/redrain.html
www.bsn.org.uk/view_all.php?id=11615
www.earthfiles.com/news/news.cfm?ID=1103&category=Science
www.geocities.com/iamgoddard/Sampath2001.pdf (PDF)
iangoddard.net/redrain.htm
education.vsnl.com/godfrey
arxiv.org/pdf/astro-ph/0601022 (PDF)
arxiv.org/ftp/astro-ph/papers/0312/0312639.pdf (PDF)
www.cnn.com/2006/TECH/science/06/02/red.rain/index.html

Prebiotic Chemistry on Titan?

An interesting new article (in-press abstract) in the International Journal of Astrobiology; new evidence from Cassini for cryovolcanism on Titan which may have provided the conditions for prebiotic chemistry for long time periods.

Rock Coatings May Help Answer Question of Life on Mars

Desert varnish, a dark shiny coating on rocks and common in deserts on Earth, may contain preserved traces of ancient Martian microbes, as it does terrestrial ones, if it is also found on rocks in Martian deserts (essentially the whole planet!).

Desert varnish had already possibly been seen on Mars by the Viking and Pathfinder landers. Similar coatings were also seen and analyzed more recently
by the Spirit rover, early in the mission. In that case, on the volcanic rock Mazatzal, they seemed to be associated with past liquid water.