By Day and Night, New Mars Images Reveal Lots of Ice

March 1 -- New images taken by NASA's Mars Odyssey spacecraft reveal the distant planet both by day and, for the first time, by night.

So far even these earliest images indicate the planet is chock-full of ice.

"The signal we've been getting loud and clear is there's a lot of ice on Mars," said William Boynton, principal investigator for the gamma ray spectrometer instruments on the craft, during a press conference today.

Scientists have already concluded that water exists on Mars, but these images, showing that ice may be abundant on the planet, bolster theories that life exists or once existed on Mars.

Looking for Hydrogen

Gamma ray spectrometers "read" the abundance and distribution of chemical elements and minerals on the planet's surface by measuring characteristic gamma rays reflected from different minerals and elements as cosmic rays strike the surface.

Researchers found ice on the planet's surface by detecting hydrogen, which is the main element in water. Large amounts of hydrogen were detected within the upper three feet of the planet's surface. And early assessments suggest that water ice may be distributed even beyond the planet's polar regions, where researchers had already concluded ice exists.

The images indicate that water ice is mixed in with dust and rocks under the surface for a broad region of the planet, stretching from the frozen southern polar cap north to about 60 degrees south latitude.

Jim Garvin, lead scientist of the Mars Exploration Program at NASA headquarters in Washington, D.C., emphasized the images and results are still "preliminary" and that another month or so of analysis will be needed to confirm their observations.

The Odyssey spacecraft reached Mars' orbit on Oct. 23 and began activating its scientific instruments for mapping the planet on Feb. 19.

Among its other instruments is a thermal emission imaging system that reads the range of temperatures on the planet's surface. The infrared technology on the 1,600-pound Odyssey craft doesn't depend on visual light to see and so has been able to capture the first images of Mars during nighttime.