(News from NASA’s Jet Propulsion Laboratory)
Three new views of the Martian moon Phobos have been captured by NASA’s Mars Odyssey orbiter. Taken this past winter and this spring, they capture the moon as it drifts into and out of Mars’ shadow. Combined with three previous images, these observations represent waxing, waning and full views of Phobos and show how the moon warms and cools.
The orbiter’s infrared camera, the Thermal Emission Imaging System (THEMIS), has been used to measure temperature variations across the surface of Phobos that provide insight into the composition and physical properties of the moon.
Further study could help settle a debate over whether Phobos, which is about 16 miles (25 kilometers) across, is a captured asteroid or an ancient chunk of Mars that was blasted off the surface by an impact.
The Odyssey team plans to observe crescent phases in coming months, providing a comprehensive view of how Phobos’ surface warms and cools as it rotates.
Odyssey has been orbiting Mars since 2001. It takes thousands of images of the Martian surface each month, many of which help scientists select landing sites for future missions. Learn more about Mars Odyssey here.