Monday, March 21, 2011

Postcards from Mars

The First Photographer on the Red Planet

This is as close to Mars as most of us will get, a coffee table book with photos taken by the two Mars Rovers that arrived there in January of 2004. You may remember the event, especially the landing procedure, which involved bouncing the airbag-encased landers across the Martian surface.

Jim Bell, the book's author, is the lead scientist for the Pancam colour imaging system on the Rovers. He gives an interesting behind-the-scenes account of the mission -- launch preparations, technical problems, communication challenges -- but book's main attraction is the 150 or so photos. Postcards he calls them, but not because of their size. You'll actually need a coffee table to spread out the double-page fold-outs. There are four of them, each almost four feet long.

The two rovers, Spirit and Opportunity, arrived on opposite sides of the planet, Gusev Crater and Meridiani Planum -- not the most exciting places visually or scientifically, but for landing purposes they were a necessary trade-off. Nearly half of spacecraft send to Mars in the last 40 years have failed.


Gusev Crater was thought to have once have been a lake, but Spirit found no sedimentary rocks, only a rugged lava plain with "dry, primitive volcanic basalts." It therefore set out for the Columbia Hills, 3-4 km distant, where it discovered evidence of layering in outcrops.

Along the way it overcame a wonky wheel and power problems caused by dust on the solar panels. By utilizing slopes oriented toward the sun, and with the fortuitous intervention of the wind, NASA scientists were able to keep the rover alive.

The panoramas are mostly flat desert-like expanses littered with rocky rubble. The light is dim, and the sky is a paler shade of the rust-coloured terrain.


Meridiani turned out to be very different from Gusev -- darker soils, prominent sand dunes, and weathered outcrops that reminded me of the Canadian Shield. More importantly there were BB-sized hematite "blueberries," and a mineral called jarosite in layered sedimentary deposits -- "key evidence that there was once liquid water on Mars...either on the surface in a lake or shallow sea, or just below the surface in extensive underground aquifers or groundwater systems."

The presence of water, however, does not guarantee an environment hospitable to life. On Mars the abundance of sulfur might have resulted in water too acidic for organic molecules to form.

More Mars

A cool companion to this book is the documentary film, Roving Mars. It recreates the Rovers' journey with a combination of actual images and computer-animated graphics. A delightful bonus is the hour-long episode, "Mars and Beyond," that aired in 1957 on the TV program "Disneyland," and is introduced by Walt himself.

When the book and the film came out in 2006, the two rovers were still functioning, having far exceeded their expected travelling distance of 600 meters and life expectancy of 90 Martian days (aka "sols," 39 minutes longer than Earth days). In 2009 Spirit got mired in soft sand, but Opportunity is still carrying out its mission. Current info on the rovers, including updates from Opportunity, is available at the following sites:

Mars Exploration Rover Mission
NASA - Mars Exploration Rovers

Finally, more info about the book can be found on the author's website, including a few images from the book.