Curiosity discovers dazzling white rock on the Red Planet... and suffers another computer glitch

Following last week's announcement that Curiosity had found conclusive evidence that Mars was once capable of supporting life, NASA's rover has made some more discoveries that show that Gale Crater was a "very viable, habitable environment." In other news, Curiosity's plutonium-powered laser has now fired more than 40,000 shots -- and after developing a fault in its primary computer and switching to the backup, Curiosity's backup has now suffered a glitch of its own.

As you may know, Curiosity recently used its percussive drill to become the first ever human-made spacecraft to bore into the surface of another planet. In the process, it discovered that its current location -- Yellowknife Bay -- was once submerged in flowing water. (See: NASA’s Curiosity rover confirms that life could’ve survived on Mars.) What you may not know is that Curiosity has another highly scientific way of breaking rocks: By driving over them. Recently, Curiosity used its one-tonne might to crush a seemingly innocuous rock -- but, instead of finding dull brown-black basalt, a brilliant white mineral was revealed. This white mineral was so bright that it actually blinded the Mastcam, which wasn't prepared (calibrated) for such a sensor-blowing revelation.

While the rock, dubbed Tintina, hasn't been tested with one of Curiosity's more accurate instruments, the bright white is a strong indicator that the rock is made from a hydrated mineral -- probably hydrated calcium sulfate in this case. In scientific terms, the presence of water is dictated by reflectance of near-infrared light; in the image below, taken by Mastcam, you can see how the white parts of the rock are the parts that also reflect near-infrared light. NASA's scientists think that it might be the same white mineral that causes the light-colored veins found in rocks around Yellowknife Bay. In both cases, the deposits were left behind by flowing water -- probably caused by melting water-ice. At this point, it looks like Yellowknife Bay would've been perfect for sustaining life -- but still the search continues for actual evidence that life ever existed on Mars.

In other news, ChemCam -- Curiosity's plutonium-powered laser-induced breakdown spectrometer (LIBS) -- has now fired 44,000 shots at more than 1,000 different locations, producing more than a gigabyte of data. ChemCam operates by melting a target with its laser, and then imaging the gases that are released. By measuring the light radiation produced by the hot gases, the atomic properties of the gases can be accurately divined (spectrometry).

Finally, Curiosity is back in "safe mode" for the second time in as many weeks, due to a software bug. It seems that Curiosity has some kind of built-in protection program that self-checks the rover's filesystem and software -- a lot like an anti-malware tool. The bug caused an unrelated file to be appended to another file that was having its integrity checked, causing the check to fail, seemingly causing the robot to automatically drop into safe mode -- a low-power mode that keeps a communication link open with NASA, but prevents any higher processes (such as moving around or using its instruments). "This is a very straightforward matter to deal with," says Richard Cook, the Curiosity project manager. "We can just delete that file, which we don't need any more, and we know how to keep this from occurring in the future."

The previous glitch, which saw part of the master computer's memory being corrupted, was much more serious, requiring Curiosity to switch over to its backup Rover Compute Element (RCE). The memory corruption bug has since been fixed by NASA, meaning Curiosity yet again has two working computers at its disposal. Due to the successive glitches, the Curiosity mission has essentially been on hold since the start of March, though scientific observations should begin again in the next few days.