A Doomed Martian Moon Has A Story To Tell
Discovered in 1877 by the American astronomer Asaph Hall, the enigmatic duo of Martian moons, dubbed Phobos and Deimos, have both bewitched and bewildered planetary scientists trying to understand their many mysteries. The Martian moons are small and misshapen little objects, frequently considered to be captured asteroids, that were snared by the Red Planet's gravity long ago--after they had both escaped from the Main Asteroid Belt between Mars and Jupiter. Phobos is both the larger of the two moons, as well as the one that is closest to its rust-colored parent-planet, and it orbits a mere 3,700 miles from the Martian surface, closer to its parent body than any other known moon in our Solar System. Indeed, Phobos is so close that it orbits its planet much faster than Mars rotates, finishing an orbit in only 7 hours and 39 minutes. In October 2017, astronomers announced that NASA's longest-lived mission to the Red Planet has obtained its first peek at Phobos, in its quest to gain a deeper understanding by exploring it in infrared wavelengths.
The Thermal Emission Imaging System (THEMIS) camera aboard NASA's Mars Odyssey Orbiter observed the little potato-shaped moon on September 29, 2017. Planetary scientists have now combined visible-wavelength and infrared data to create an image color-coded for surface temperatures on this intriguing tiny moon. Phobos has been considered for a potential future human-mission outpost.
"Part of the observed face of Phobos was in pre-dawn darkness, part in morning daylight, commented THEMIS Deputy Principal Investigator Dr. Victoria Hamilton in an October 4, 2017 NASA Jet Propulsion Laboratory (JPL) Press Release. Dr. Hamilton is of the Southwest Research Institute, headquartered in San Antonio, Texas. The JPL is in Pasadena, California.
Studying the new image from left to right presents a sequence of times of day on the mysterious Martian moon, ranging from before dawn, to sunrise, to increasing quantities of time following the Martian dawn. This provides valuable information about how rapidly the ground on the Red Planet warms up, which is related to the texture of its rust-colored surface. Sand warms or cools much more rapidly than rocks or pavement.
"Including a predawn area in the observation is useful because all the heating from the previous day's sunshine has reached its minimum there. As you go from predawn area to morning area you get to watch the heating behavior. If it heats up very quickly, it's likely not very rocky but dusty instead," Dr. Hamilton continued to explain in the JPL Press Release.
The Thermal Emission Imaging System (THEMIS) camera aboard NASA's Mars Odyssey Orbiter observed the little potato-shaped moon on September 29, 2017. Planetary scientists have now combined visible-wavelength and infrared data to create an image color-coded for surface temperatures on this intriguing tiny moon. Phobos has been considered for a potential future human-mission outpost.
"Part of the observed face of Phobos was in pre-dawn darkness, part in morning daylight, commented THEMIS Deputy Principal Investigator Dr. Victoria Hamilton in an October 4, 2017 NASA Jet Propulsion Laboratory (JPL) Press Release. Dr. Hamilton is of the Southwest Research Institute, headquartered in San Antonio, Texas. The JPL is in Pasadena, California.
Studying the new image from left to right presents a sequence of times of day on the mysterious Martian moon, ranging from before dawn, to sunrise, to increasing quantities of time following the Martian dawn. This provides valuable information about how rapidly the ground on the Red Planet warms up, which is related to the texture of its rust-colored surface. Sand warms or cools much more rapidly than rocks or pavement.
"Including a predawn area in the observation is useful because all the heating from the previous day's sunshine has reached its minimum there. As you go from predawn area to morning area you get to watch the heating behavior. If it heats up very quickly, it's likely not very rocky but dusty instead," Dr. Hamilton continued to explain in the JPL Press Release.
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