Starship Asterisk*

Hi all,

Here's a stumper for any Mars experts. While processing my Mars images from last night, I found a strange feature over Acidalia (top left of the animation below). I made this 5-frame animation of the green-light images. The feature appears in all the channels, but is most visible in blue and green and least visible in IR. Also, it moves with the planet (ruling out dust motes on the sensor) and seems to rise over the limb. Fog rolled in after this, so there is no additional data later than this. If anyone caught Mars after 2:15UT last night, please check your images... particularly after 2:51UT.

http://exosky.net/images/Mars-anim_20-March-2012.gif

Any ideas or thoughts on what this might be?

thanks,

Wayne

I would say that it is likely to be a frozen CO2 cloud. Weather circulating over the northern polar region snowing dry ice crystals on the north pole

I think it is similar in appearance to high altitude clouds that have been observed on Mars in the past at a similar location and season. Never seen such a high resolution ground-based image of one though. What observatory is this from?

BMAONE23 wrote:
I would say that it is likely to be a frozen CO2 cloud.

Weather circulating over the northern polar region snowing dry ice crystals on the north pole

Water-ice clouds, rather:

http://www.solarviews.com/eng/marscld.htm wrote:

Click to play embedded YouTube video.

"Clouds scoot across the Martian sky in a movie clip consisting of 10 frames taken by the Surface Stereo Imager on NASA's [Polar] Phoenix Mars Lander." This clip accelerates the motion. The camera took these 10 frames over a 10-minute period from 2:52 p.m. to 3:02 p.m. local solar time at the Phoenix site during Sol 94 (Aug. 29), the 94th Martian day since landing. Particles of water-ice make up these clouds, like ice-crystal cirrus clouds on Earth. Ice hazes have been common at the Phoenix site in recent days.

<<Although not as pronounced as on Earth, clouds are common features on Mars. The Martian atmosphere has only a trace of water vapor; however, the temperature and pressure is such that the atmosphere is usually close to saturation and produces clouds. Even from Earth based telescopes, clouds have been observed by transient brightening on the surface of Mars.

Numerous cloud patterns have been seen from the Marineer and Viking spacecraft and have been classified into various categories (Carr, 1981; French et al. 1981):

• Lee waves. These clouds form in the lee of large obstacles such as mountains, ridges, craters and volcanoes. The air in these regions undergoes wavelike oscillations.
  Wave clouds. These clouds appear as rows of linear clouds. They are common at the edge of the polar caps.
  Cloud streets. These clouds exhibit a double periodicity. They appear as linear rows of cumulus-like, bubble-shaped clouds.
  Streaky clouds. These clouds have a direction without periodicity.
  Fog or ground hazes. Fog usually occurs in low areas such as valleys, canyons and craters. It forms during the coolest times of the day such as dawn and dusk. Sometimes ground haze is caused by dust in the atmosphere; however, if the atmosphere is clear ground fog can be easily identified.
  Plumes. These are elongated clouds. They appear to have a source of rising material and in many case are composed of dust particles.>>

Mars clouds look a little different from earth clouds. I don't think I really understand what makes photos of Earth from space seem like the clouds and atmosphere are glued to the surface while this Mars photo clearly shows the cloud above the surface and the rest of the atmosphere as well. Is Mars's atmosphere proportionally higher than Earth's? Ugh, I'm horrible at explaining what I am trying to ask.

A Cloudy Day (ESP_025914_2540)
http://asterisk.apod.com/viewtopic.php?f=29&t=28031