ORIGINAL POST 30 MAY 07
UPDATED (see below) 1 SEP 07
Okay, this has almost nothing to do with nanotechnology, but it's so cool I just have to report it.
From an article by Emily Lakdawalla on the Planetary Society Weblog:
Today's set of image releases from the Mars Reconnaissance Orbiter HiRISE team included this one, of a fairly bland-looking lava plain to the northeast of Arsia Mons. Bland, that is, except for a black spot in the center. What's that black spot? It's a window onto an underground world.
This black spot is one of seven possible entrances to subterranean caves identified on Mars. . . The hope for the HiRISE images was that we could see some details from inside the hole. But as you can see by the [image below], there is absolutely nothing visible inside that hole. It's black black black black black. . .
Think about that. All these orbiters at Mars, and most of them are just seeing the surface and atmosphere. To be sure, there are two instruments up there -- MARSIS on Mars Express and SHARAD on Mars Reconnaissance Orbiter -- that are probing the shape of the subsurface with ground-penetrating radar. But neither of those instruments have the resolution necessary to tell us what the inside of this cave looks like. It might as well be in the greatest depths of space. Here there be dragons. What's down there? Are there stalactites and stalagmites and crystals, or is it just a vast open room or tunnel?
Hat tip to Jamais Cascio, who tells us:
What's particularly exciting about these caves is that they may be the best places to find extant life on Mars. According to USGS scientists [PDF]:Subterranean void spaces may be the only natural structures on Mars capable of protecting life from a range of significant environmental hazards. With an atmospheric density less than 1% of the Earth’s and practically no magnetic field, the Martian surface is essentially unprotected from micro-meteoroid bombardment, solar flares, UV radiation and high-energy particles from space.
Thermal imaging of the voids show that they maintain a relatively constant temperature, remaining relatively warm in the cold Martian night.
Anybody want to go caving?
UPDATE: Found on physorg.com (hat tip to Michael Anissimov)...
The High Resolution Imaging Experiment (HiRISE) camera on NASA's Mars Reconnaissance Orbiter has confirmed that a dark pit seen on Mars in an earlier HiRISE image really is a vertical shaft that cuts through lava flow on the flank of the Arsia Mons volcano.