Into the depths of a Martian canyon

Valles Marineris is a huge rift valley on Mars, a canyon system dwarfing the Grand Canyon on Earth. A portion of it, Melas Chasma, is featured in new images from the Mars Express spacecraft. In this spot, the canyon is about 9 kilometres (5.6 miles) deep, and sulphate deposits are evidence of a former lake. There are also other water-cut channels in the immediate vicinity. There are additional and larger images, including 3D perspectives, here.

Credit: ESA/DLR/FU Berlin (G. Neukum)

Perhaps the proposed Martian airplane will fly over this area for even better views…?

Extensive carbonate deposits reported on Mars

According to a new paper published in Nature Geoscience, large deposits of carbonates have been found buried about six kilometres (four miles) below the surface of Leighton crater (exposed by the original impact), near the huge shield volcano in the Syrtis Major region. Small deposits have been found before on the surface, including recently by the rover Spirit, but much larger amounts would be additional evidence of a warmer, wetter ancient Mars, with a thicker atmosphere of carbon dioxide. Notably, carbonates are formed in non-acidic (alkaline) liquid water. So this finding would again reinforce the idea of ancient lakes, seas or oceans on the surface. But were those waters cold or warm? What about those icebergs? It seems like every time another piece of the puzzle is found, it just raises more questions…

Ingredients for life in Titan’s atmosphere?

There have been some interesting findings from a research team led by the University of Arizona, indicating that amino acids and other complex building blocks of life may be present in Titan’s atmosphere, and that the processes involved can occur in the upper atmosphere of a planet or moon, without the need for liquid water as has long been presumed.

Simulations of Titan’s atmosphere, subjected to UV radiation (like from the sun, as happens in the upper Titanian atmosphere) produced complex organic molecules such as amino acids and nucleotide bases, the primary building blocks of life on Earth. The Cassini spacecraft has already confirmed organic molecules there, but there are some more complex ones in the atmosphere which haven’t been identified yet.

As has been reported previously, there has has been a growing interest lately in the possibility of primitive life on Titan, despite the very cold temperatures, given the hydrological cycle of rain, rivers, lakes and seas, but with liquid methane instead of water. If prebiological molecules are being massively produced, as seems to be the case, could anything be alive in those alien lakes and seas…?

More information here, here, and here.

Asteroid dust found in Hayabusa?

JAXA, the Japanese space agency, has reported finding, as hoped for, particles inside the Hayabusa spacecraft’s sample collecting capsule which it believes are from the asteroid Itokawa. Hayabusa returned to Earth last June after a seven-year journey to the asteroid and back.

According to different articles though, there seems to be some confusion as to what was found. Popular Science, The Daily Galaxy and The Telegraph are saying that the particles might be evidence of extraterrestrial life… but other articles from Japan such as this one mention only that the particles are likely to be extraterrestrial (from the asteroid itself) and not Earthly contaminants and might simply provide clues to the origin of the solar system and life. Two very different things.

So which is it? Going by past experience, it is most likely the latter, information which was misinterpreted and distributed by other media. But we should learn more as the analysis continues and more specific details are made public.

Addendum (October 9, 2010):

Another new article in The Mainichi Daily News in Japan indicates that the particles are mostly rocky in nature, but are diverse in composition.

A “Perrier ocean” on Enceladus?

A new study suggests that the water-ice geysers on Saturn’s moon Enceladus originate from a bubbly, salty subsurface sea or ocean, a variation of previous theories.

New image of the plumes, released October 1, 2010. Credit: NASA/JPL/Space Science Institute

From the article:

“Matson and his colleagues came up with a computer model that accommodates much of what is known about the geysers of Enceladus. Their findings support the supposition that a salty sea flows under the moon’s surface.

This ocean has gases dissolved in it, the theory goes. As the seawater flows up to and through the tiger stripe fissures, its pressure drops and the gases bubble up, Matson said — making the ocean fizzy, like Perrier. The relatively warm water and expanding gas feed the jets.

When the bubbles pop, they throw off a fine spray that contains salt and other materials, which Cassini spotted in Enceladus’ plumes. Then the seawater, having dumped much of its warmth on the moon’s surface ice, cools and sinks back through cracks, rejoining the ocean and its heat-transferring circulation system.”

Perrier, anyone?


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