Wednesday, March 11, 2009

Deimos captured in new light

The previously rather drab little Martian moon of Deimos can now be seen in a new light, thanks to the latest pictures shot by the High Resolution Imaging Science Experiment, or HiRISE, on board NASA's Mars Reconnaissance Orbiter. Captured on February 21st, 2009, using near-infrared, and red and blue-green filters, the new images show subtle colour variations on the surface. These are probably caused by the exposure of surface materials to the space environment, which leads to darkening and reddening. Brighter and less-red surface materials have seen less exposure to space due to recent impacts or downslope movement of regolith. The pictures can be seen here.

Thursday, March 05, 2009

Usagi Yojimbo v Martians

Usagi Yojimbo is a rather bizarre comic book written and drawn by its creator Stan Sakai for the last 25 years. Its hero is, wait for it, a Samurai rabbit! But if Sakai has his way, his Japanese Bunny will soon be battling Martians. Usagi Yojimbo is generally set at the beginning of Edo period in Feudal Japan (the early 17th century) and was inspired by the famous Japanese swordsman Miyamoto Musashi, but Sakai has also branched out on occasion, even going so far as to transplant a version of the character into space for a spin off series. Celebrating the 25th anniversary of his character, Sakai spoke at the recent WonderCon convention, and revealed he has plans to pit the Samurai against H.G. Well's Martians. Said Sakai, "It would be set two hundred years before Wells’ time and would involve a very old Usagi fighting a Martian tripod."

Tuesday, March 03, 2009

Drip drip of evidence builds for water

The jury is likely to be out for some time, but intriguing images have come to light that seem to show drops of water that had formed on the landing strut of the Phoenix Mars lander. The "drops" are seen over a period of days to form, drip and merge down the struts. Study leader and Phoenix co-investigator Nilton Renno of the University of Michigan believes that the drops may have started life as saline mud that was splashed up onto the struts during the landing of the Phoenix probe. Salt in the mud would then have absorbed water vapour from the atmosphere to form the watery drops. The "water" might contain a substance called perchlorates, which acts as a powerful antifreeze, so though the drops may have partially frozen at night, they would have been in a liquid state during daylight hours. However, caution is urged, as it would not be likely that this highly salty water would be a good place for life to form.

Recent water on Mars - in a manner of speaking.

Planetary geologists at Brown University have found a gully fan system on Mars that they think was formed about 1.25 million years ago by flowing water. That may seem like an age, but in geological terms it's a blink of an eye, and if ever proven, means Mars had flowing water a lot more recently than previously supposed. The gully system is located on the inside of a crater in Promethei Terra, an area of cratered highlands to be found in the southern mid-latitudes. Mars Daily has an excellent story on the discovery.