odyssey_1stpic_011031 The first image of Mars from NASA's Odyssey spacecraft was released today, showing a strip of the Red Planet as seen by the craft's infrared camera and showing mission managers that the camera works as planned.
The camera, one of two onboard Odyssey, measures heat instead of visible light.
"The image exceeded our expectations," said Greg Mehall, lead engineer for the instrument at Arizona State University. "Everything looked very, very good. The instrument's health and telemetry looked good."
Dust in the Martian wind
The purpose of the image is not to generate science findings, but to test the camera. The instrument would serve as a backup for monitoring dust storms on Mars in the event that a similar camera on the Mars Global Surveyor, also orbiting Mars, were to malfunction.
The MGS camera is in fine health. But watching for dust storms is critical over the next several weeks as Odyssey uses Mars' thin atmosphere to slow itself down, a maneuver called aerobraking that will eventually put the probe into a circular orbit about 250 miles above the surface.
The craft's current egg-shaped orbit dips low into the atmosphere over the north pole of Mars, where its solar panels act like brakes. Extra dust can warm the atmosphere and puff it up, which affects how low Odyssey would be allowed to go. Too much friction could destroy the solar panels.
"If we have a quick development of a dust storm, that can change the dynamic pressure at the north pole where we're doing the drag passes," Mehall explained in a telephone interview.
Dust storms have been raging on Mars for months, at times enveloping the entire planet. NASA officials said last week that the storms were subsiding but could flare up at any time.
Mehall said the storms they worry about typically develop over the south pole and migrate northward. So the image released today is a view of Mars looking up from the south pole, when Odyssey is at its greatest distance from the planet.
The spacecraft was about 13,600 miles (22,000 kilometers) above the planet when the image was acquired. It was in the midst of its ninth orbit around Mars. Odyssey arrived at Mars Oct. 23.
The new picture covers a length of more than 3,900 miles (6,500 kilometers). It has a resolution of approximately 5.5 kilometers per pixel (3.4 miles per pixel), or picture elements, at the point directly beneath the spacecraft, according to officials at NASA's Jet Propulsion Laboratory, which runs the Odyssey mission.
In future scientific mapping, several such images will be combined to form a complete picture of Mars in the infrared. The infrared camera is planned to have a resolution of 100 meters per pixel (about 300 feet per pixel) when it gets into its final mapping orbit. The instrument is so sensitive it can detect temperature differences of as little as 1 degree Fahrenheit -- enough to spot a warm pool of underground water, if one exists.
While the new image is not intended to produce any scientific findings, it could prove useful nevertheless.
"You know scientists," Mehall said. "They're going to find something interesting to pull out of it."
Details of the new image
It is late spring in the Martian southern hemisphere. The extremely cold, circular blue feature is the south polar ice cap, made mostly of carbon dioxide and at a temperature of about -184 degrees Fahrenheit, according to a press statement from JPL.
The cap is more than 540 miles (900 kilometers) in diameter today, but it will shrink as summer progresses.
Clouds of cooler air blowing off the cap can be seen in orange extending across the image to the left of the cap. The cold region in the lower right portion of the image shows the nighttime temperatures of Mars, demonstrating the "night-vision" capability of the camera. The warmest regions occur near local noontime. The ring of mountains surrounding the 540-mile (900-kilometer) diameter impact basin Argyre can be seen in the early afternoon in the upper portion of the image.
The thin blue crescent along the upper limb of the planet is the Martian atmosphere.
Optical image may come soon
Odyssey's visible-light camera was also turned on and appears to be working properly, Mehall said. But it has not been instructed to produce an image yet. The infrared camera is seen by scientists as the more important of the two, and mission managers have their hands full with the aerobraking procedure for now.
Mehall said there is hope that the visible light camera can be allowed to take a small snapshot of the south polar ice cap sometime soon, but there are no firm plans to do that.
The newly released image was taken Tuesday. Normally, images are processed for about two months before they are released for scientific investigation. Computer software adjusts the images, pixel-by-pixel, to remove artifacts such as lines and streaks and to calibrate the appearance of the data based on tests performed in a vacuum chamber on Earth, prior to launch.
Mehall said the image released today has not been fully processed, though many hours of computer time were spent on it.
"If you just want a picture you can show the world, it's not that much work," he said.
Regular mapping of Mars is expected to begin in February and should result in a steady flow of visible and infrared images. Odyssey will use its cameras and other instruments to search for subsurface water and ice, to understand the chemistry of Martian soil, and to measure the deadly radiation environment of the Red Planet.
SPECIAL REPORT: Full Coverage of the Odyssey Mission to Mars
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