Mars May Get Rings Like Saturn

Mars may get a ring system similar to Saturn’s in 20 to 40 million years, new research from the University of California at Berkeley suggests. The new research paper, authored by graduate student Tushar Mittal and planetary scientist Dr. Benjamin Black, theorizes that since Mars’ largest and innermost moon, Phobos, is gradually spiraling closer to the Martian surface, it will eventually break apart and leave a ring of debris around the Red Planet.

In a research paper published this week in Nature Geoscience, Mittal and Black’s team theorize that the gravitational pull of Mars is causing enormous stress on Phobos, and calculate that the moonlet is not likely to survive. Furthermore, its process of total annihilation will form a ring around Mars with a similar density to Saturn’s famous rings. Dr. Black summed up the study to Science Daily.

“While our moon is moving away from earth at a few centimeters per year, Phobos is moving toward Mars at a few centimeters per year, so it is almost inevitable that it will either crash into Mars or break apart,” Black said. “One of our motivations for studying Phobos was as a test case to develop ideas of what processes a moon might undergo as it moves inward toward a planet.”

The researchers believe that a similar process may explain the formation of the rings around other planets in the solar system, including Saturn, which boasts 62 moons of its own (and perhaps more in the past). Collisions between these moons and between other spacial bodies likely formed the materials necessary for its rings. Jupiter and Uranus also boast rings with similar origins. Neptune’s largest moon, Triton, is the only other moon in the solar system known to be moving closer to its planet, and may experience a similar fate to Phobos.

Because Phobos is highly fractured to begin with and has a low density, the resulting rubble would continue to orbit Mars and would eventually encircle the planet in a ring instead of immediately impacting on the surface. Nature reported that, according to Dr. Black, once the break-up of Mars’ moon begins in earnest, the ring will form relatively quickly, taking only weeks or perhaps even days.

“If you were standing on the surface of Mars, you could grab a lawn chair and watch Phobos shearing out and spreading into a big circle,” Black says.

According to estimates from the study, the ring would last anywhere between 1 to 100 million years before raining back down to the surface near the equatorial regions.

Studying the disintegration of moons and the formation of planetary rings is relevant to learning more about the evolution of our solar system. According to the research paper, a moon in orbit around a planet has three possible fates: to slowly drift away like Earth’s moon, to stay in a stable orbit for an indefinite period of time, or to eventually close the space between itself and its parent body. While scientists have known that Mars’ largest moon falls into the third category for decades, this new study paints a clearer picture of what this will look like.

As of right now it is not clear whether the debris ring around Mars would be visible from Earth.

Mars has long been a source of wonder and the subject of intense scientific study. Our sister planet regularly makes the news as new discoveries are made. On September 28, 2015, NASA confirmed evidence of flowing liquid water on Mars.

[Image via NASA]