The surface of Mars' BIGGEST moon, Phobos, covered in the groove That May Have Been Huge caused by massive boulders rolling budgets across surface following an asteroid impact.
Other Planets and moons are theres With SIMILAR ditches and scratches, says Kenneth Ramsley at Brown University in Rhode Island, none pocket as Completely covered in them as Phobos – the-moon's groove are up to 30 kilometers long and 200 meters wide.
Ramsley and James Head, ALSO at Brown, Used a SIMULATION of-the Mars Phobos system to examine WHETHER From These Groove Could come rolling stones.
The pair says These stones would Have Been From STICKNEY ejected crater, Which Was whens formed a rock about one kilometer across smashed Into Phobos around 150 million years ago.
Phobos the small and close to Mars, so the-planet's gravity would have acted on-the boulders, Causing some way to roll for around-the-the-the moon and Creating Intersecting lines we see on budgets That surface today. The whole process would have Taken Less Than 12 hours an after-the impact, Ramsley says.
There's the one area are on the moon With Almost no lines at all. The SIMULATION That showed because That Has lower elevation zone and Phobos Has low gravity, would have-the boulders rolled Simply Into space before returning to the-surface, like a cartoon character running off a cliff and landing THENI On the other side.
But theres's a problem: we do not see ANY boulders are on the surface. That Ramsley said this, too, May BE explained by debris from The STICKNEY impact. "All of That extra Rubble That doesnt stay-on-the-surface gets trapped in orbit around Mars and returns to the-the-Scenes of Crime WITHIN hits and Phobos in 1000-years again," he says. That bombardment Could have smashed up boulders and hidden-the-the-the smallest of Groove Under a layer of dust.
Journal reference: Planetary and Space Science, DOI: 10.1016 / j.pss.2018.11.004
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