NASA Mars Orbiter Captures Dazzling Thermal Image Of Phobos, The Largest Martian Moon


Mars’ moon, Phobos, has been getting a lot of attention from NASA lately. The larger of the two Martian moons, Phobos recently made headlines after the InSight Mars lander spotted the shadow of its eclipse as the moon passed in front of the sun, The Inquisitr covered in March. The following month, it was the Curiosity rover’s turn to set its sights on the tiny Martian moon and to photograph a splendid annular eclipse as Phobos transited the sun, per a previous report from The Inquisitr.

Now, another NASA Mars mission has eyed the intriguing alien moon – and beamed back a stunning set of photos showing a previously unseen face of Phobos, the space agency announced earlier this week. According to NASA, it was the venerable 2001 Mars Odyssey orbiter that cast its diligent eye over the Martian moon, snapping a glorious thermal view of Phobos during a full moon phase.

While the photo in itself is quite extraordinary, the feat is rendered even more significant by the fact that this is the first time Odyssey has managed to snag a snapshot of Phobos during its full moon phase. The Mars orbiter has been closely studying the Martian moon since September of 2017. For the past year and a half, Odyssey has been staring at the 14-mile-wide moon through the lens of its heat-vision camera, the Thermal Emission Imaging System (THEMIS), and has successfully taken photos of Phobos during the half-moon phase, both in 2017 and in 2018.

After all of this time, the spacecraft has finally succeeded in capturing a thermal view of Phobos during the full moon. Unveiled by NASA on Thursday, the glorious photo shows Phobos as it has never been seen before.

Thermal image of Mars' moon Phobos as captured by NASA's 2001 Mars Odyssey orbiter.
Thermal images of Mars' moon Phobos, as captured by NASA's 2001 Mars Odyssey orbiter. Featured image credit: NASA/JPL-Caltech/ASU/SSI

As NASA officials point out, the new Odyssey photo offers a unique perspective on Phobos, portraying the Martian moon “like a rainbow-colored jawbreaker.”

“This new image is a kind of temperature bull’s-eye — warmest in the middle and gradually cooler moving out,” said Jeffrey Plaut, Odyssey project scientist at NASA’s Jet Propulsion Laboratory (JPL) in Pasadena, California.

“Each Phobos observation is done from a slightly different angle or time of day, providing a new kind of data.”

The reason why Phobos “looks like candy” in the latest Odyssey photo – as NASA puts it – has to do with the thermal representation of the Martian moon, as captured by the spacecraft’s camera.

“Each color in this new image represents a temperature range detected by Odyssey’s infrared camera,” notes a statement from NASA.

By design, THEMIS “can detect changes in surface temperature as Phobos circles Mars every seven hours.”

“Different textures and minerals determine how much heat THEMIS detects.”

Color image of Phobos, captured by NASA's Mars Reconnaissance Orbiter on March 23, 2008.Featured image credit: NASA/JPL-Caltech/University of ArizonaWikimedia Commons/Resized

While the previous images snagged by the 18-year-old orbiter – specifically the half-moon views of Phobos – served to offer precious clues about the moon’s surface textures, the latest thermal pic showing the glowing, rainbow-like orb of the full moon could help scientists study the material composition of Phobos.

“With the half-moon views, we could see how rough or smooth the surface is and how it’s layered,” said THEMIS co-investigator Joshua Bandfield, a senior research scientist at the Space Sciences Institute in Boulder, Colorado.

“Now we’re gathering data on what minerals are in it, including metals.”

Two metals that scientists are particularly interested in are iron and nickel. By finding out how abundant these metals are in the composition of Phobos, and how they’re mixed with other minerals, scientists could be one step closer to unlocking the mystery of the Martian moon’s origin. The two main theories regarding the birth of Phobos speculate that the object is either an asteroid captured by Mars’ gravitational pull or an actual chunk of the red planet expelled into space after a massive collision in the planet’s ancient past.

Alongside the new thermal images of Phobos, NASA also released a visible-light version of the three photos. Unveiled in the form of a GIF made up of three panels, the snapshots are stacked in order from the most recent one (April 24) to the oldest one (September 29, 2017) and even offer a glimpse of Mars’ other moon, the 7.8-mile-wide Deimos.

“The apparent motion is due to movement by Odyssey’s infrared camera, rather than movement by the moon,” explained the JPL, which manages the Odyssey mission.