The planet’s gravitational pull will destroy the moon in 50 million years, producing a ring of dust and rocks.

Phobos, the larger of Mars’ two moons, is slowly spiraling toward the Red Planet and is expected to meet a catastrophic fate within the next 50 million years, according to astronomers studying the Martian system. Due to tidal forces exerted by Mars, Phobos’ orbit is shrinking by approximately 1.8 meters (six feet) every century.

In a study published in the Journal of Geophysical Research, scientists predict that as the moon gets closer, it will either crash into Mars or be torn apart, forming a ring of debris around the planet.

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Phobos, measuring 27 by 22 by 18 kilometers (17 x 14 x 11 miles), orbits Mars three times per day at an extremely close distance. In some regions of Mars, the moon is not always visible due to its proximity. Unlike Earth's Moon, which is moving away from the planet, Phobos is being pulled inward by Mars’ gravity.

As it continues this inward spiral, it will eventually cross the Roche limit - the point at which tidal forces will exceed the moon’s ability to hold itself together.

When Phobos reaches this critical distance, the gravitational pull of Mars will rip it apart. The debris will then spread out and form a ring system, much like those seen around Saturn or Uranus, NASA planetary scientist Dr. Elena Vargas said in a statement.

The process of Phobos’ disintegration is expected to take thousands of years once it reaches the Roche limit.

Over time, the rubble will either remain in orbit as a temporary ring or gradually fall to the surface, bombarding Mars with impacts. The most recent studies suggest that within 50 million years, Mars will either gain a prominent ring or experience a series of meteorite showers from Phobos' remains.

If Phobos survives the tidal forces and crashes into the planet, it will leave a huge crater on the surface. However, it’s unlikely, NASA assures.

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Evidence of Phobos’ instability is already visible in its fractured surface. The moon’s most distinctive feature, Stickney Crater - a 9.7-kilometer-wide (6-mile-wide) impact scar - dominates nearly half of the moon's surface.

Deep grooves and cracks radiate from this crater, likely caused by the moon’s internal stress and past collisions with space debris. Scientists speculate that Phobos was once struck so hard that it nearly shattered, but Mars' weak gravity kept it intact.

Phobos, like its smaller sibling Deimos, is composed of C-type rock, similar to carbonaceous chondrite asteroids. Its surface has been bombarded for eons, covering it in a layer of fine, dusty regolith. This dust is so poor at retaining heat that temperatures on Phobos range from 25°F (-4°C) in direct sunlight to -170°F (-112°C) in the shadows - an extreme contrast for such a small body.

Despite ongoing research, Phobos' origins remain uncertain. Some scientists believe it was once an asteroid captured by Mars’ gravity, while others argue that its composition and orbit suggest a different formation history.

While Phobos is doomed, its smaller counterpart, Deimos, will likely survive. Deimos orbits farther from Mars and is slowly drifting away, much like Earth’s Moon. As a result, Deimos is not subject to the same destructive tidal forces and will likely remain in orbit for billions of years.

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Astronomers continue to study Phobos closely, using spacecraft observations from NASA’s Mars Global Surveyor and other missions. Understanding the moon’s fate could provide insight into planetary rings, tidal forces, and the long-term evolution of moons in our Solar System.

The two moons were discovered in 1877 by American astronomer Asaph Hall. Phobos is named after the Greek god of fear and panic, who is the son of Ares (Mars) and twin brother of Deimos.

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