Phobos, the larger of the two moons that orbit Mars, is reportedly “cracking under pressure” and could be destroyed in the future, a new study revealed. According to Science News, a study conducted by Terry Hurford, a planetary scientist at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, seems to indicate that Phobos is being ripped apart by the force of Mars’s gravity. He added that the small moon is also gradually changing its shape and is being turned into the shape of a football. His findings were revealed on November 10 during the meeting of the American Astronomical Society’s Division for Planetary Sciences.
“As Phobos gets closer… it gets pulled out into a football shape,” Hurford said on Monday.
When the pull of the martian gravity reaches a certain point, Hurford predicts that the moon will break apart into tiny pieces of rock. He added that the grooves observed on the surface of Phobos are most likely caused by the stress that the moon endures as it changes it shape due to Mars’ gravitational pull.
“The changing shape causes stresses that we think form the grooves,” he added.
According to Earthsky, scientists initially thought the grooves had some connection with a large crater on the surface of Phobos known as crater Stickney. This crater is quite huge — almost accounting for half the surface area of Phobos. The assumption was that the grooves seen on the surface of Phobos were the creation of the crater. However, a more recent study revealed that the grooves should have in that case radiated from the large crater. Instead, they figured out the presence of a “focal point” that was separate from the crater. On further analysis, they deduced that the grooves are the early signs of structural failure that is threatening to destroy Phobos in the future.
In many ways, Phobos, along with its smaller counterpart Deimos, are unique natural satellites. Phobos, for example, is believed to be the closest satellite orbiting its parent planet Mars. It is on an orbit just 3,700 miles (6,000 kilometers) from Mars. Just to compare, our own moon lies nearly quarter of a million miles away from the Earth. According to estimates, Mars is pulling Phobos towards itself at a rate of over 6.6 feet every 100 years. At this rate, we can expect Phobos to be destroyed between 30 and 50 million years.
— NASA (@NASA) November 10, 2015
— Discovery News (@DNews) November 11, 2015
While that is an insanely long period of time considering the fact that us humans have only been on Earth for the past 100,000 years, it is still a relatively short period of time if you look at it on a galactic perspective.
Alan Harris, a scientist at the Space Science Institute in Boulder, Colorado, was among the group of scientists that initially studied Mars, Phobos, and its mysterious grooves. Back then, he blamed the presence of the grooves on the gravity of Mars. However, his theory, like that of many others, did not find much support from other members of the scientific community.
“It all fits together pretty well,” says Alan Harris now.
Meanwhile, in a statement, NASA announced that Phobos is perhaps not the only body in the solar system that is being pulled apart by gravity. Triton, the largest moon of planet Neptune, also gets a similarly fractured surface and is thought to be collapsing inwards.
[Image Via Wikimedia Commons Via NASA/JPL-Caltech/University of Arizona]