* Astronomy

Blobrana · L

RE: Martian clouds

Blobrana · L

Mars Water-Ice Clouds Are Key to Odd Thermal Rhythm

Researchers using NASA's Mars Reconnaissance Orbiter have found that temperatures in the Martian atmosphere regularly rise and fall not just once each day, but twice.
Temperatures swing by as much as 58 degrees Fahrenheit (32 kelvins) in this odd, twice-a-day pattern, as detected by the orbiter's Mars Climate Sounder instrument.
The new set of Mars Climate Sounder observations sampled a range of times of day and night all over Mars. The observations found that the pattern is dominant globally and year-round. The report is being published in the journal Geophysical Research Letters.
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Blobrana · L

Martian Snow

Blobrana · L

Researchers calculate size of particles in Martian clouds of CO2 snow

In the dead of a Martian winter, clouds of snow blanket the Red Planet's poles - but unlike our water-based snow, the particles on Mars are frozen crystals of carbon dioxide. Most of the Martian atmosphere is composed of carbon dioxide, and in the winter, the poles get so cold - cold enough to freeze alcohol - that the gas condenses, forming tiny particles of snow.
Now researchers at MIT have calculated the size of snow particles in clouds at both Martian poles from data gathered by orbiting spacecraft. From their calculations, the group found snow particles in the south are slightly smaller than snow in the north - but particles at both poles are about the size of a red blood cell.
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Blobrana · L

Martian clouds

Blobrana · L

Mysterious cloud spotted on Mars

Amateur astronomers are puzzling over a seemingly anomalous cloud that has shown up on images of Mars taken over the past few days. Is it really a cloud, or a trick of the eye? Does it really extend 150 miles up from the surface, as some of the observers suggest? And what churned up all that stuff, anyway? The amateurs and the pros will be trying to resolve those questions before the phenomenon fades away.
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Blobrana · L

ESA orbiter discovers water supersaturation in the Martian atmosphere

New analysis of data sent back by the SPICAM spectrometer on board ESA's Mars Express spacecraft has revealed for the first time that the planet's atmosphere is supersaturated with water vapour. This surprising discovery has major implications for understanding the Martian water cycle and the historical evolution of the atmosphere.
Although numerous spacecraft have visited Mars over the past half a century, very few direct measurements of the vertical structure of the planet's atmosphere have been made. Since most of the spacecraft instruments have looked down at the surface, it has only been possible to infer the horizontal distribution of gases in the atmosphere, leaving the question of how water vapour is being mixed into the atmosphere almost unexplored.
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Blobrana · L

Martian clouds in motion

The images that compose this animation were taken on October 14, 2010, on Mars Express' 8676th orbit, and show an area within Noachis Terra to the west of Hellas basin, around 45 degrees south, 38 east. There are two components to the apparent motions of the clouds. One is real west-to-east cloud motion over the two-minute period of the animation (readable from the motions of the shadows along the ground). The other component has to do with the different look angles of the different channels of HRSC and the significant thickness of the cloud layer. In the first frame, HRSC was looking forward (northward) along its south-to-north orbital path; in the last frame, it was looking backward (southward). Because of this changing perspective, the upper-level clouds appear to move southward with respect to the lower-level clouds.
The colour comes from red, green, and blue channels of the HRSC channel and is an overlay applied to the animation, so the colour information is actually not animated -- only the brightness information moves. This works visually because Mars is relatively monochromatic.