Probing the Martian Pole

Mockup of Phoenix (top) and 'Robinson Crusoe on Mars'
(bottom)—both set in Death Valley National Park…
Credit: NASA (top), Paramount Pictures (bottom)It's that time of the Martian year again: when a flying saucer from Earth appears in the skies of Mars. Imagine if there actually were Martians up there: what's science fiction here on Earth would pass for reality on the Red Planet—and a routine occurrence at that!

This time the flavor of the day is the Phoenix Lander, courtesy of NASA, scheduled to land on May 25th at about 4:38 PM PDT. We'll be watching live NASA coverage of the landing at Chabot Space & Science Center that afternoon, if you'd care to join us…

Following somewhat in the footsteps of the Viking landers of the 1970s, Phoenix's primary mission is to look for evidence of life, or at least the chemical conditions that might be suitable for life to exist. The two Viking landers carried small chemical laboratories that analyzed soil samples scooped up from the surface, as does Phoenix.

While its mission parallels that of Viking, one big difference from Phoenix is its destination: the Northern Polar Ice Cap of Mars. The Vikings landed much farther south in the mid latitudes. Phoenix is targeting the ices of Mars' arctic region.

Growing up, one of my favorite sci-fi films was Robinson Crusoe on Mars. Made in 1964, the same year that Mariner 4, the first space probe to Mars, was launched, RCOM made a descent stab at imagining what it was like. So what if the main character walked around in apparent t-shirt weather and with sufficient atmospheric pressure to keep his blood from boilin--he still wore a respirator that doled out oxygen from an ever-dwindling supply tank, a nod to Mars' thin atmosphere.

A couple of other things our astronaut Robinson Crusoe found on that fictional Mars that we are now looking for on the real one: liquid water and life…Our hero found small caches of water (with the help of a monkey) in grottos between the rocks, and, lo and behold, living in that water was a vine-like life form with edible fruit or tubers. He even took a foot-trek, along with his guy Friday, to the polar ice cap…

(I also loved the film because some of its "Martian terrain" scenes were shot in my favorite spot on Earth, Death Valley…)

Though evidence of past liquid water action seems to be all about the planet, Phoenix certainly won't find any brooks or pools or grottos of spring water, owing at least in part to the frigid arctic region it will set feet on--an arctic zone on a world where the warmest temperatures in the tropics might reach levels of the coldest climates on Earth. What's important about landing on Mars' ice cap is that Phoenix is almost certain to dig up some water--albeit frozen.

And it is the chemical compounds either locked up in that ice or preserved by its proximity that Phoenix is interested in. (Similarly, climatologists on Earth study ice cores from Antarctica to analyze the trapped and preserved gases of Earth's atmosphere of past millennia.)

We wish Phoenix a happy landing, and look forward to the first images and discoveries from the Martian North Pole. And I'm fairly confident the epic polar adventure ahead won't resemble in the least another "great" film of 1964: Santa Claus Conquers the Martians….

Benjamin Burress is a staff astronomer at The Chabot Space & Science Center in Oakland, CA.

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