Mysterious and beautiful seasonal patterns in Martian sand dunes: geysers, microbes, or something else?

Landscapes of Mars

Since 2006, NASA's Mars Reconnaissance Orbiter (MRO) has been orbiting Mars, currently circling approximately 300 km (187 mi) above the Martian surface. On board the MRO is HiRISE, the High Resolution Imaging Science Experiment camera, which has been photographing the planet for several years now at resolutions as fine as mere inches per pixel. Collected here is a group of images from HiRISE over the past few years, in either false color or grayscale, showing intricate details of landscapes both familiar and alien, from the surface of our neighboring planet, Mars. I invite you to take your time looking through these, imagining the settings - very cold, dry and distant, yet real.

Bit slow to load, but well worth the wait!

Mountaineers measure lowest human blood oxygen levels on record.

The expedition found the average arterial oxygen level to be 3.28 kilopascals or kPa (with the lowest value being 2.55 kPa); the normal value in humans is 12-14 kPa and patients with a level below 8 kPa are considered critically ill.

Cool!

Also, a landslide the size of the U.S., though it disappointingly happens to be on Mars.

Hat tips for both to The Adventure Blog.

Plasma rocket!

Scientists in Costa Rica have run a plasma rocket engine continuously for a record of more than four hours, the latest achievement in a mission to cut costs and travel time for spacecraft.

The Ad Astra Rocket Company, led by Costa Rican-born former

NASA astronaut Franklin Chang-Diaz, said on Wednesday it hopes to use its rocket engines to stabilize space stations in a few years, and then to power a trip to Mars within two decades.

Evidence for a once wet Mars.

"This is some of the best evidence Spirit has found for water at Gusev," said Albert Yen, a geochemist at NASA's Jet Propulsion Laboratory, Pasadena, Calif. One possible origin for the silica could have been interaction of soil with acid vapors produced by volcanic activity in the presence of water. Another could have been from water in a hot spring environment. The latest discovery adds compelling new evidence for ancient conditions that might have been favorable for life, according to members of the rover science team.

I will just note that the reasoning used to speculate about Martian 'terrain' is precisely that used by Lyell.