Tag: Mars

New data from Curiosity has confirmed that the winds of Mars have been the primary force shaping the red planet’s landscape for billions of years.

The new data suggests that Mount Sharp once filled Gale Crater, and it was the winds that eroded it away to create the impression that it is the crater’s central peak. Instead it appears that it is the crater’s original floor!

Below the fold is the video from the link showing a number of dust devils imaged by Curiosity.

This link provides a gif animation showing the surprisingly significant changes to the ripples in the sand dunes directly below Curiosity that take place in only one day. The changes are astonishing, and show that even though Mars’ atmosphere is far thinner than Earth’s, it is capable of moving things quickly across the Martian surface.
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The uncertainty of science: Despite substantial evidence by Curiosity that Gale Crater once had running water and even lakes, the rover has also found no evidence that the atmosphere ever had enough carbon dioxide in its atmosphere to warm the climate enough to allow that water to flow as a liquid.

Mars scientists are wrestling with a problem. Ample evidence says ancient Mars was sometimes wet, with water flowing and pooling on the planet’s surface. Yet, the ancient sun was about one-third less warm and climate modelers struggle to produce scenarios that get the surface of Mars warm enough for keeping water unfrozen.

A leading theory is to have a thicker carbon-dioxide atmosphere forming a greenhouse-gas blanket, helping to warm the surface of ancient Mars. However, according to a new analysis of data from NASA’s Mars rover Curiosity, Mars had far too little carbon dioxide about 3.5 billion years ago to provide enough greenhouse-effect warming to thaw water ice.

The same Martian bedrock in which Curiosity found sediments from an ancient lake where microbes could have thrived is the source of the evidence adding to the quandary about how such a lake could have existed. Curiosity detected no carbonate minerals in the samples of the bedrock it analyzed. The new analysis concludes that the dearth of carbonates in that bedrock means Mars’ atmosphere when the lake existed — about 3.5 billion years ago — could not have held much carbon dioxide.

Does anyone but me see the faulty scientific reasoning here? Basically, these scientists appear to be assuming that the only global warming atmospheric molecule that exists is carbon dioxide. And because Mars has little carbonates in its surface, meaning it had little past CO2 in its atmosphere, there thus no way Mars’ atmosphere could have been warmed enough to allow water to flow as a liquid.

Balderdash! On Earth, the most important global warming component in the atmosphere is water, not carbon dioxide. Moreover, there are other atmospheric components, such as methane, that are also more important than CO2 in warming the climate. In fact, carbon dioxide as a trace gas in the atmosphere plays only a tiny global warming role. On Mars it is just as likely that other atmospheric components, such as water and methane, provided the necessary warming. To assume it has to be carbon dioxide suggests to me that these scientists have become so caught up with the human-caused global warming scare here on Earth that they have lost the ability to consider other possibilities on Mars.

Nonetheless, this remains the fundamental scientific mystery of Mars. We have found enormous evidence on Mars that water once flowed on its surface. We have also found no explanation so far that would explain how that was possible.

In a science update on Curiosity’s research in Gale Crater, this Science journal article today gives a good overall update on Curiosity’s technical condition.

Since early December 2016, Curiosity hasn’t been able to drill. The problem, likely a stuck brake on the mechanism for extending the drill bit, is serious. “There is apprehension,” says Ashwin Vasavada, Curiosity’s project scientist at the Jet Propulsion Laboratory in Pasadena, California. But the drill still responds intermittently. “We’re not in a situation where it’s completely dead.”

Still, the clock is ticking for the aging rover, and some outside scientists regret not having used a wet chemistry cup. Rocks have punctured its wheels, and the output of its decaying radioactive power source has dropped by 15%. Jack Mustard, a planetary scientist at Brown University, says he understands the team’s hesitancy. But he wished the “mission had moved more quickly with the wet chemistry experiments,” he says. “I am eager to see what we can learn.”

The wet chemistry cup, designed to look for organic life, is an experiment that requires use of the drill but the science team has held off doing. Now it might be too late.

At the moment Curiosity is approaching [see Sol 1598-1599] the small hill that had been to its southwest in my January 18, 2017 update and shown in the image above. I had thought they might make a side trip there on their way up Mount Sharp, and they have, with their actual route taking them around the backside of the hill.