An amateur astronomer in West Chester, Penn. took a picture of a curious Martian cloud several nights ago that has the community of Mars observers abuzz. Wayne Jaeschke photographed Mars on the evening of March 19 with a 14-inch telescope and noticed the plume after processing his images.
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.
When I first started processing these images,I was ready to smash my telescope because of the terminator "defect!". But thanks to Wayne's great work my scope was spared. This "cloud" on the morning limb is truly extraordinary. Evening limb orographics are never this high. This feature reminds me of the SL-9 impact plumes that were carried over the limb of Jupiter in July of 1994. Moreover,it is prominent on the red as well as the blue channel. At the risk of sounding daft,perhaps it is of impact and not meteorological origin. I agree with Roger Venable that one must take the terminator into account when determining the height of this cloud. However Mars is 98.4% illuminated now,so the terminator effect is minimal -- the cloud still has dramatic altitude. Furthermore I have never seen a cloud like this even when the Tharsis orographics are on the evening terminator during perihelic apparitions. Who said that Mars is boring this year??
The cloud is located at Longitude 190.5º and Latitude 43.7ºS (measured from Wayne's March 19th, 0255ut image.)
I measured the cloud on Don Parker's image and find it on the order of 250 km above the limb. That is well outside the sensible atmosphere of Mars, so it cannot be a water based cloud which tend to be no more than 10 to 15 km altitude. The only thing that makes any sense to me is either a huge volcanic eruption or an asteroid impact. The color is also dark, unlike water based clouds. Clif Ashcraft
I imaged Mars last night March 23rd between 4:30 and 6:00 UT with above seeing condition. At this point, I'm not sure yet if I detect anything limb cloud of the same place. I was tired but I will process the images tonight.
Perhaps it is settled down whatever it was? I do not believe it was the meteorological activity that took place that high in the atmosphere. It is much, much higher than Olympus Mons. Something that was being "forced" to have the clouds that shot upward. It must be some kind of volcanic-like activity. But I would leave up to the experts or even the MRO scientists.
I will post my images later on.
Frank J M
Originally posted by Phage
Ice cloud...that's my vote.