Cognitive Labs

According to the story published in the Proceedings of the National Academy of Sciences and covered in Space.com, it appears that some of the landforms in dry valleys on Mars are the result of glaciation...advancing and retreating of glaciers, formed from the accumulation of snow into compacted ice over tens or hundreds of thousands of years.

There is no return to the perchlorate discussion yet. However, this implies that the climate was far more earth-like than it is now, since it supported H-2-0 precipitation, which mean atmospheric pressure was much higher than it is now, and temperatures must have been in the narrow band (relatively speaking) when snow falls.

The thicker atmosphere would have deflected ultraviolet radiation.

If it's too hot, there will only be water vapor and maybe liquid water, if it's too cold - it won't snow. On earth, snow does not fall below temperatures of -40 C. Heaviest accumulations of snow occur when there is significant atmospheric mixing of low and high temperatures and surface temperatures may be anywhere from around 0 C (32 F) to -30 C or so. Glaciers form from yearly accumulation of snow that doesn't melt completely. On earth the glacier accumulation range at present is sea level in the arctic to 6000 meters high at the equator.

This has varied in the past. So, possibly Mars would have been habitable by forms of organisms recognizable on the earth today. With all the ice and snow, water - and cloud cover - Mars would have been much brighter in the sky than it's present iron-rich desert appearance and would have looked more like earth, an azure marble, through a small telescope.

Labels: astrobio, dry, mars, perchlorate, valleys

A Thor Intercontinental Ballistic Missile

Perchlorate, the substance present in the recent soil sample analyzed on the surface of Mars, is not obstructive of life. However, it is a common ingredient in explosive arms and is in the same category as RDX and white phosphorous as an environmental hazard.

In fact, NASA's Tuesday press conference to clarify the perchlorate information released on Monday discloses that perchlorate can occur naturally and does on earth-for example, in Chile's atacama desert.

Researching a little further, as recently as 2006, a scientist showed in the lab how perchlorate can be precipitated in playas with chloride rich soils, such as found in California's Death Valley or Nevada's Black Rock Desert, through exposure of the soils to ultraviolet radiation. These salty, chloride-rich soils are usually the remnant of old lakes and oceans. In the case of Death Valley, this was the giant Lake Manly, Nevada was covered by the large Lake Lahontan, and Lake Bonneville covered Utah, which was more of an inland sea than a lake. This would suggest that liquid water on Mars was widespread at one time (which has been theorized for some time).

Perchlorate's main impact on human life is interference in the function of the thyroid gland in the case of overexposure, which is unlikely on Mars.

It is also true that perchlorate is a main ingredient in solid rocket fuels (although not of hydrazine, the type of fuel used by the Martian lander).

Perhaps more significantly, perchlorate is a key ingredient in diverse celebratory combustibles such as roman candles, firecrackers, launched fireworks, and flares, and also has extensive military uses: bullets, artillery shells, missiles, rockets, bombs, and blasting caps.

In fact, perchlorate is classified as a hazardous material in several government publications (here are two references: 1 | 2 ) and component of military munitions, defined as

"confined gaseous, liquid, and solid propellants, explosives,pyrotechnics, chemical and riot control agents, smokes, and incendiaries used by DOD components, including bulk explosives and chemical warfare agents,chemical munitions, rockets, guided and ballistic missiles, bombs, warheads, mortar rounds, artillery ammunition, small arms ammunition, grenades, mines, torpedoes, depth charges, cluster munitions and dispensers, demolition charges, and devices and components thereof"

If it is not naturally occurring, which is the likelier scenario, what else could explain it? if it turns out to be distributed across the surface, this would indicate either vast oceans sometime in the past or perhaps some kind of planetwide cataclysmic event involving the discharge of weaponry.

Either way, the finding is curious.

Labels: nasa, perchlorate, phosphorous, rdx, thor

While one test showed soil on Mars contained some of the minerals seen on earth, such as magnesium, potassium, and sodium, in addition to the repeat confirmation of frozen water on the surface of Mars - a later test found a substance called perchlorate, which can be naturally formed or artificially distilled but is an ingredient in rocket fuel. While it is indicated as non-supportive of life, perchlorate exists on earth.

Speculation amongst other scientists and science journalists is that the sample could have been contaminated by the rocket thrusters of the descending probe. It appears that any additional announcements on this topic will have to wait until some point in the future.

Labels: perchlorate