See Mars in wide-screen
Posted: Friday, July 11, 2008 6:10 PM by Alan Boyle
NASA / JPL / UA /TAMU / James Canvin
This is just one small part of a panorama showing Phoenix Mars Lander's
surroundings, produced by weather researcher and former astronomer James
Canvin. Click on the image for a zoomable HD View version (free plug-in required).
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It's prime time for the Mars probes: NASA's Phoenix Mars Lander is at the halfway point of its 90-day primary mission, and the Mars Reconnaissance Orbiter is sending back a flood of images from orbit. The pictures contain an incredible amount of detail - as the latest jaw-dropping panoramas illustrate.
One of the coolest views is a work in progress that's being put together by amateur image wizard James Canvin. He's a weather researcher and former astronomer who often posts his work to Unmanned Spaceflight and Emily Lakdawalla's Planetary Society Weblog. As more raw imagery come in from the Phoenix lander, Canvin adds it to a home-brewed mosaic that shows a 360-degree view of the probe's surroundings in Mars' north polar region.
The latest version of the Phoenix's mission success panorama (a.k.a. the Peter Pan, in honor of Phoenix principal investigator Peter Smith) appears on Lakdawalla's blog as well as on Martian Vistas, Canvin's own home on the Web. With his permission, we've created a zoomable HD View version - but if HD View doesn't work for you, you can still check out Canvin's 10,000-pixel-wide version on Martian Vistas.
"I'd better get working on the final version!" Canvin told me in an e-mail.
In today's posting, Lakdawalla explains why Canvin and other amateurs can get their own versions of NASA imagery on the Web before NASA does. Mission scientists use a more painstaking system for processing their images precisely and scientifically - while the amateurs (and, truth be told, most of us in the outside world) are interested primarily in a good-looking picture.
A thrilling view of Victoria Crater's Cape Verde, based on data from NASA's Opportunity rover, provides a prime example: The wide reddish sky and thin Martian clouds add to the drama of the scene, but they're artistic enhancements rather than the real thing.
Art plus science
Producing pictures of Mars in color is an art as well as a science. Sometimes the technical limitations of spacecraft operating tens of millions of miles from Earth limit what they can do. Even if everything works perfectly, it can take a while to combine the imagery taken through different filters. That's why you'll almost always see the black-and-white versions of Martian scenes first.
A prime example is the stunning picture that Mars Reconnaissance Orbiter captured on May 25, showing the Phoenix lander descending toward its landing spot on the end of a parachute. The black-and-white version of the image was released a day after the landing, but the partially colorized version didn't come out until this week.
NASA / JPL / UA
This partially colorized picture, captured by the high-resolution camera on NASA's
Mars Reconnaissance Orbiter, shows the Phoenix Mars Lander descending on the
end of its parachute. The inset photograph highlights the parachute and lander.
Click on the image for a larger version. Can you spot the heat shield falling away?
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The scientists who control the orbiter's High Resolution Imaging Science Experiment, or HiRISE camera, could get the color data only for a narrow strip of the panorama. Unfortunately, the lander was outside that target strip when the picture was taken.
"For this reason, processing the color bands did not take a high priority in the days following acquisition of this image," the HiRISE team explained.
Nevertheless, the color strips reveal extra information about the crater in the background: There's a slight bluish tint along the right edge of the rightmost strip, indicating that the bowl of the crater contains a dusting of ice or frost.
The high-resolution version of the image holds another surprise: The HiRISE team says the picture appears to show the spacecraft's heat shield falling away, as a tiny black speck below and to the right of the drifting parachute and lander. Can you find it? This detail image from the HiRISE Web site helps you spot the speck.
The heat shield also appears as a speck in HiRISE's latest view of the Phoenix landing site. Check out this high-resolution image to see the lander's parachute and backshell, the black dot of the heat shield, and the lander itself toward the lower right. If you've got your 3-D glasses handy, you'll get a kick out of HiRISE's red-blue stereo pictures.
HiRISE's pictures of the Phoenix site are just the tip of the iceberg. The full image catalog, updated weekly, shows a wide variety of Martian vistas - usually in false shades of blue and orange that are meant to emphasize the subtle differences in surface composition.
But wait ... there's more: Phoenix and the Mars Reconnaissance Orbiter are only the latest probes on the Martian scene. To get the full picture, you'll want to keep tabs on NASA's Mars rovers as well as Mars Odyssey and Europe's Mars Express. And don't forget our special section on Mars exploration, "Return to the Red Planet."
