Mars' Largest Moon Phobos Shows Ripping Signs Due to Extreme Gravitational Force

As shown in recent research, Mars' biggest moon Phobos is being torn apart by the Red Planet's strong gravitational forces. The peculiar patterns spanning Phobos' surface, which have been originally thought to be scarring from an ancient asteroid collision, are dust-filled canyons that have become larger as the moon is stretched out by gravity forces.

Phobos is on a collision path with Mars, having been gouged and nearly broken by a massive impact crater and pummeled by millions of meteorite strikes. Phobos is the bigger of Mars' two moons, measuring 17 by 14 by 11 miles or 27 by 22 and 18 kilometers.

Phobos is approaching Mars at a pace of six feet (1.8 meters) per hundred years; if it continues at this rate, it will either collide with Mars within 50 million years or fragment into a ring. The 6-mile (9.7-kilometer) crater Stickney is its most noticeable feature, with its impact producing stripe patterns throughout the moon's surface. Stickney was discovered during Mars Global Surveyor to also be covered in fine dust and to have rocks tumbling down its sloping surface, as stated by NASA.

Phobos Mysterious Stripey Surface

The most peculiar characteristic of Phobos, though, is its cryptic stripey surface. The moon is covered in parallel grooves, often known as surface striations. The most commonly recognized explanation holds that the striations developed when an asteroid collided with Phobos in the past, leaving behind a 6-mile (9.7-kilometer) wide crater known as Stickney on the moon's side.

Now, a recent research published Nov. 4 in The Planetary Science Journal reveals that the grooves are the consequence of the moon being progressively torn apart by Mars' tremendous gravity as Phobos rounds the planet's surface.

The study proposes that when one object, in this example Phobos, approaches a wider base, like Mars, the weaker body begins to expand out in a line more toward the larger body. The tidal force is what causes this.

Throughout the instance of Phobos, the tidal pressure generated on the moon is expected to rise as Phobos approaches the Martian surface, eventually exceeding the gravity keeping the satellite together. According to the study, at that moment, Phobos will be entirely split apart, and the debris will most likely create a thin ring from around the planet, similar to Saturn's rings.

Prior and Future Studies

Despite previous studies claiming that tidal pressures caused Phobos' tiger stripes, this idea has been generally discounted due to the moon's powdery or "fluffy" structure, which makes such fissures impossible to develop.

The new study employed computational models to test the theory that perhaps the moon's fluffy exterior is supported by a fairly cohesive sub-layer. The simulation discovered that a subsurface hard shell might have generated deep canyons into which surface dust could have fallen, resulting in the apparent grooves on the surface.

Considering Phobos as just a rubble-pile interior covered by a cohesive layer, the researchers discovered that tidal strain might form parallel cracks with regular spacing. At its present pace of decay, Phobos will reach Mars in roughly 40 million years. However, if tidal forces are already pulling the moon apart, the satellite might be fully destroyed far sooner, according to the experts.

The Japanese Space Agency (JAXA), will embark on a brand-new mission called Martian Moons eXploration (MMX) in 2024, to land a spacecraft on both Phobos and Deimos, as reported earlier by Science Times. The specimens returned in 2029 would have to provide light on what's up with Phobos' striped surface.

Check out more news and information on Phobos in Science Times.