AirSpaceMag.com

Phobos as viewed (in false color) by NASA's HiRISE camera in 2008.

Mars has not been a happy place for the Russian space program. The nation’s attempts to explore the Red Planet, going back more than 50 years, have produced a long litany of failures. The most recent misfire came 15 years ago, when the instrument-laden Mars 96 probe, instead of heading out into the solar system, burned up in the atmosphere and scattered pieces over Chile and Bolivia.

That crash effectively put the Russian planetary program out of business — until now.

On Tuesday a Zenit rocket is scheduled to lift off from Kazakhstan to start the Phobos-Grunt spacecraft on its 10-month voyage to Mars. If all goes well, on Valentine’s Day of 2013, after several months of circling the planet, the lander will touch down on the surface of the moon Phobos to start collecting samples of dirt (“grunt” in Russian). Four days later, a return vehicle will lift off in the moon’s low gravity and bring the samples back to Earth.

We’ll have more details on the Phobos-Grunt mission next week. Meanwhile, here’s some background from Anatoly Zak, the author of our 2008 article, and an animation (with Russian subtitles) from the Roscosmos space agency that shows how it’s all supposed to go.

Cue the Lawrence of Arabia theme. Actually, I prefer the soundtrack that the Mars Exploration Rover team used for this time-lapse video showing Opportunity’s 13-mile trek from Victoria crater to Endeavour crater. They took accelerometer data from the rover and converted it to audible sound, which gets louder when the robot is moving over rocky ground, and quieter when it’s crossing sand dunes. The trip to Endeavour took three years, compressed here to three minutes. Here’s a view from Opportunity‘s navigation camera, taken just last Monday.

What draws me to Titan is the mystery. After 50 years of robotic exploration most other objects in the solar system have given up their secrets, at least to a first order. But Saturn’s largest moon is hidden by a perpetual cloud cover, so we have to work harder to see what’s underneath.

Which is why I find maps like this so appealing. A research team led by the University of Nantes in France stitched together six years’ worth of infrared images taken by the Cassini spacecraft over the course of 70 Titan flybys to produce a global mosaic. Because infrared penetrates the clouds, the surface is revealed. In this false-color composite, highlands appear bright and equatorial dune fields appear dark.

The mosaic varies in resolution, depending on how close Cassini was to the surface at the time a particular image was taken. But some of the fuzzy areas will get sharper. Another 48 Titan flybys are planned between now and 2017.

Among the things one expects to find while sifting through former President Bill Clinton’s stuff, a lost moon rock might be low on the list.  The half ounce piece, one of the Goodwill Moon Rocks brought back on Apollo 17, was given to Arkansas three decades ago and reported missing sometime last year. Wednesday morning, reports the AP, an archivist who was looking through the former governor’s papers opened a box and discovered it. No one knows how it got in there, but the archivist, Bobby Roberts, who directs the Central Arkansas Library System, seems content to set ‘em up and knock ‘em down, “I guess it’s one more Arkansas mystery solved.”

Apollo 11 moon rocks. Photo credit: NASA

This recently found moon rock is one of about 200 small fragments presented as gifts to foreign nations, U.S. states and territories. All were sliced from a single Apollo 17 sample, number 70017, and many are unaccounted for today. Various investigations have been pursued over the years to track down these and other missing moon rocks, including Operation Lunar Eclipse, the joint sting operation between NASA, the U.S. Postal Service and U.S. Customs that recovered the Goodwill Moon Rock originally given to Honduras.  Another somewhat famous escapade includes the interns at Johnson Space Center who smuggled out a 600 pound safe containing samples from all the Apollo missions (the F.B.I. caught them).

NASA’s Office of the Inspector General keeps tabs on any information surfacing about moon rocks, both to collect missing pieces and to sweep counterfeit rocks off the market. Updates are published in the office’s semi-annual reports — just last year they recovered a Goodwill Moon Rock intended as a gift to Cyprus (pdf), however, “The plaque had been intended for delivery by a U.S. diplomat to the people of Cyprus as a gift when hostilities broke out in that country. The plaque had remained in the custody of the diplomat until his death and was recovered from his son.”

Wikipedia’s moon rocks page collects more stories, such as the ill-fated gift to Ireland: the Apollo 11 rock ended up in a landfill. (Their Apollo 17 rock is safe in a museum, at least.) Clearly, some of these will never be recovered.  But sometimes, every once in a while, you can just open a box.

Over the years, spacecraft have seen plenty of dried-up riverbeds on Mars, along with rocks that formed in watery environments eons ago. No question about it, the Red Planet used to be wet. NASA can stop sending press announcements about water in the Martian past. We got it.

Now scientists are reporting something much more exciting: the first strong evidence of liquid water currently on Mars.

Pictures taken by the HiRISE camera on the Mars Reconnaissance Orbiter show dark streaks at the foot of steep slopes, which scientists say are probably the traces of salt water that reaches the surface. We’re not taking about rushing streams. In their paper in Science magazine reporting the findings, Alfred McEwen of the University of Arizona and his co-authors write: “We assume [the streaks] are usually dry at the surface, perhaps wet only in the subsurface and perhaps in small surface areas while moving.” So maybe it’s like damp beach sand after a wave has just retreated. The streaks, which range from 2 to 15 feet in width, appear by the hundreds in seven different places (20 more locations are under investigation) during the Martian summertime, when temperatures can reach as high as 80° F. The seasonal flows, if that’s what they are, have been traced in the HiRISE images for as long as three Martian years.

HiRISE pictures of Newton Crater, spanning more than a year, show dark streaks interpreted as being traces of flowing salt water. (Image: NASA/JPL-Caltech/U of Arizona)

As often happens, the scientists can’t be 100 percent sure. McEwen says the best way to nail down the case for liquid water is through laboratory studies on Earth. Part of the problem is that water on Mars doesn’t behave like water on Earth, and is unlikely to last very long on the surface due to the planet’s cold temperatures and the weak atmospheric pressure. That makes it difficult to observe from afar unless you happen to be looking at just the right time.

Best of all would be to visit those locations with a lander. Unfortunately, the Curiosity rover planned for launch to Mars in November—the most sophisticated lander ever sent to the planet—won’t go anywhere near the newly found streaks. And even if it could, NASA wouldn’t send it there. Watery environments may be the best places to look for signs of life, but Mars scientists face an ethical Catch-22: By the rules of “planetary protection,” you can’t send an unsterilized rover to a place where it might contaminate native Martian life. And sterilizing a rover like Curiosity is time-consuming and expensive.

It’s a dilemma.