New research suggest Mars' largest moon, Phobos, was formed from Martian debris excised by an ancient impact.

Because Phobos and Deimos are dark in color, some planetary scientists believe the two Martian moons are asteroids pulled into orbit by Mars' gravity. Other researchers argue the shape of the moons' orbits don't support an asteroid-capture origin.

"They say that, given the inclination and the details of Phobos' orbit, it's almost impossible that it was captured," Tim Glotch, a geoscientist at Stony Brook University in New York, said in a news release.

In an effort to solve the mystery of the moons' beginnings, scientists returned to a dataset collected in 1998 by NASA's Mars Global Surveyor mission.

Spectrographic analysis of the Martian moons typically relies on visible and infrared light, both of which reveal signatures similar to the radiation reflected by the surfaces of D-class asteroids. The Mars Global Surveyor data, however, features mid-infrared observations of Phobos, the darker of the two moons.

Mid-infrared light includes body heat. Just like visible light, thermal energy can be broken down into spectral bands, revealing a unique signature.

The mid-infrared analysis -- detailed Monday in the Journal of Geophysical Research -- showed Phobos heat signature is most similar to Martian surface features.

"At these wavelength ranges, the Tagish Lake meteorite doesn't look anything like Phobos, and in fact what matches Phobos most closely, or at least one of the features in the spectrum, is ground-up basalt, which is a common volcanic rock, and it's what most of the Martian crust is made out of," Glotch said. "That leads us to believe that perhaps Phobos might be a remnant of an impact that occurred early on in Martian history."

The match isn't perfect, but Phobos' heat signature suggests the moon is at least partially composed of Martian crust -- perhaps mixed with remnants of the impacting body.

The new research isn't sufficient to settle the debate once and for all, authors of the study acknowledged.

"But it will help keep the discussion moving forward," said Marc Fries, a planetary scientist and curator of cosmic dust at NASA's Johnson Space Center.

"The really cool thing is that this is a testable hypothesis, because the Japanese are developing a mission called MMX that is going to go to Phobos, collect a sample and bring it back to Earth for us to analyze," Glotch said.

Related Links
Mars News and Information at MarsDaily.com
Lunar Dreams and more

Tweet

Thanks for being here; We need your help. The SpaceDaily news network continues to grow but revenues have never been harder to maintain. With the rise of Ad Blockers, and Facebook - our traditional revenue sources via quality network advertising continues to decline. And unlike so many other news sites, we don't have a paywall - with those annoying usernames and passwords. Our news coverage takes time and effort to publish 365 days a year. If you find our news sites informative and useful then please consider becoming a regular supporter or for now make a one off contribution.
SpaceDaily Contributor $5 Billed Once credit card or paypal		SpaceDaily Monthly Supporter $5 Billed Monthly paypal only

NASA Launching Mars Lander Parachute Test from Wallops Sep 7
Wallops Island, VA (SPX) Sep 03, 2018
NASA will conduct the third in a series of parachute tests for possible future missions to Mars during the flight of a Terrier-Black Brant IX suborbital sounding rocket in the morning on Sep. 7, 2018, from the agency's Wallops Flight Facility in Virginia. The launch window for the 58-foot tall rocket is from 9:30 a.m. - 12:30 p.m. EDT. The backup launch days are Sep. 8 - 15. The rocket will carry the Advanced Supersonic Parachute Inflation Research Experiment (ASPIRE) from NASA's Jet Propuls ... read more