In the wake of the failure of the Mars Polar Lander in 2001, all Mars missions on NASA's docket were canceled. Engineers went over the lander tech from the canceled mission piece by piece, fixing all known problems. The Phoenix Lander is a rejuvenated form of that technology, something Mars Program Director Doug McCuistion characterized as, "reusing money that NASA and the American taxpayers already invested in this mission." The landing site is farther north than any previous Martian lander mission - it's roughly analogous to landing in the Canadian north. It won't land on the actual polar ice of Mars, but nearby, where scans have revealed the soil is made of 30-60 percent permanent ice.

Once in place, the lander will extend a 6-foot robot arm to dig down a foot and a half into the Martian soil. It can analyze samples with a microscope or an oven that will reveal the chemical and mineral makeup of the material. The form that the subsurface ice takes will reveal if a warmer Martian climate in the past allowed for liquid surface water. And if the retro thruster method of landing works, it could pave the way for larger, heavier landers in the future. It represents an updates pulse thrust version of the thruster technology last used on the Viking landers of the 1970s. Image by: NASA.

Plants use chlorophyll instead of some other pigment to drive photosynthesis because it is more efficient to absorb red and blue photons, based on the output of our sun and the light filtering attributes of our atmosphere. When they took these variables into account, the researchers found that planets around Class F and Class K stars, which are somewhat similar to our sun (Class G), would tend to have plants with either blue or red pigment, depending on the intensity of the starlight. Class M stars, aka red dwarfs, are cool stars that don't give off any ultraviolet radiation late in their lives. The relatively small amount of light available could result in black plants that try to absorb all the photons they can.

When advanced telescopes look at distant planets seeking life, they will need to know what colors to look for. If the planet has insufficient landmass, or all plants there live in the oceans, they will need to study the composition of the atmosphere with spectroscopy to determine if plant life may be present. Image by: Kenn Brown and Scientific American.

The Color of Plants on Other Worlds. [Scientific American]

1. Titan is the only moon with a thick, stable atmosphere. It's mostly made of nitrogen, with a decent helping of methane and other hydrocarbons. It's not exactly a breathable atmosphere, but it's still pretty cool. Even better, Titan has Earth-like weather. Wind and rain sweep the surface of Titan, shaping its geography and producing seasonal effects. Some scientists say Titan is a lot like a young Earth, only much colder.

2. Titan has dune seas. As much as 40 percent of the equatorial region might be covered by "sand" dunes hundreds of meters high. They probably aren't made of silicate particles the way Earth sand is. Rather, Titan's sand could be precipitated from the atmosphere. The dunes are sort of like semi-permanent snow drifts.

3. Titan has cryovolcanoes. There are mountains on Titan, along with evidence of volcanic activity. The interior of Titan probably doesn't support the same kind of heat and pressure that we find within the Earth. Instead, Titan's volcanoes might be the result of highly pressurized ice fracturing and spewing liquid water and ammonia into the atmosphere.

4. Titan has liquid features on the surface, like the hydrocarbon lakes pictured in the computer rendering above. Earlier Cassini data found proof of methane lakes in Titan's polar regions. Even more interesting, there might be an entire ocean lying beneath Titan's surface. This leads us to the best reason that Titan is awesome...

5. Titan might be our best bet for finding extraterrestrial life within our solar system. If the subsurface ocean exists, it would be made of liquid water and ammonia and would be warmer than the surface. The chemical makeup of the atmosphere and the active weather and geology have lead some scientists to propose that the conditions on Titan are right for the formation of primitive life. That's exciting. Image by Steven Hobbs via NASA.

The Drake Equation is a series of decreasing fractional probabilities that end up estimating the chance that there are other intelligent civilizations somewhere in the universe. The enormous scale of the universe virtually guarantees that a decent probability will come out of that equation. Professor Andrew Watson of the University of East Anglia has recalculated the odds, factoring in the age of the Earth. He claims that Earth is in the latter stages of its life as a planet, meaning that it took a long time for intelligent life to develop here. Therefore, such life doesn't happen easily, and must be quite rare.

I say bollocks. Watson fails to take into account a number of factors. For one thing, not every solar system follows the same life pattern as ours. Other planets may have far longer habitable periods than Earth, increasing the odds of intelligent life developing there. He also fails to consider that different environments could lead to very different evolutionary rates.

In the end, it comes back to the scale of the universe (how many galaxies can you spot in the Hubble image above?). It doesn't matter how improbable the odds of intelligent life evolving are. We know for a fact it happened once. It is almost inconceivable to think that among the unfathomable numbers of stars and planets scattered across the universe, it happened only once. Photo by: ESA and NASA.

Is there anybody out there? [University of East Anglia]

According to an early release about her scientific paper:

Scientists have long known that most compounds in living things exist in mirror-image forms. The two forms are like hands; one is a mirror reflection of the other. They are different, cannot be superimposed, yet identical in their parts.

When scientists synthesize these molecules in the laboratory, half of a sample turns out to be "left-handed" and the other half "right-handed." But amino acids, which are the building blocks of terrestrial proteins, are all "left-handed," while the sugars of DNA and RNA are "right-handed." The mystery as to why this is the case, "parallels in many of its queries those that surround the origin of life," said Pizzarello.

Years ago Pizzarello and ASU professor emeritus John Cronin analyzed amino acids from the Murchison meteorite (which landed in Australia in 1969) that were unknown on Earth, hence solving the problem of any contamination. They discovered a preponderance of "left-handed" amino acids over their "right-handed" form.

"The findings of Cronin and Pizzarello are probably the first demonstration that there may be natural processes in the cosmos that generate a preferred amino acid handedness," Jeffrey Bada of the Scripps Institution of Oceanography, La Jolla, Calif., said at the time.

The new PNAS work was made possible by the finding in Antarctica of an exceptionally pristine meteorite. Antarctic ices are good "curators" of meteorites. After a meteorite falls — and meteorites have been falling throughout the history of Earth — it is quickly covered by snow and buried in the ice. Because these ices are in constant motion, when they come to a mountain, they will flow over the hill and bring meteorites to the surface.

"Thanks to the pristine nature of this meteorite, we were able to demonstrate that other extraterrestrial amino acids carry the left-handed excesses in meteorites and, above all, that these excesses appear to signify that their precursor molecules, the aldehydes, also carried such excesses," Pizzarello said. "In other words, a molecular trait that defines life seems to have broader distribution as well as a long cosmic lineage."

ASU Researcher May Have Discovered Key to Life Before Its Origin on Earth [Eurekalert]