Mercury's fragments that scattered billions of years ago might be buried on Earth: Report

Mercury, the smallest planet in our solar system, has been looming close to the sun for billions of years and has conditions impossible to support life. And it is this extreme vicinity to the sun that birthed this doomed planet, experts have said. According to a new theory presented at the Lunar and Planetary Science Conference, few astronomers have claimed that Mercury used to be much bigger in size but continuous impacts stripped its outer layers. In fact, the impacts, coupled with intense solar radiation, were so strong that some of Mercury's fragments scattered into outer space and ended up on Earth. 

Was Mercury a super-Mercury?

Planetary scientist at the University of Lorraine in France, Camille Cartier, who presented this new theory, and her colleagues strongly support the argument that there was a super-Mercury that existed billions of years ago. In her work, Cartier noted that there are over 70,000 pieces of meteorites that have been collected from across the world and have been housed in museums. Cartier said that while most of these fragments arrived on Earth from the Moon, Mars and the asteroid belt, some of them might belong to a super-Mercury or a proto-Mercury double the planet's current size. 

In the new paper, the experts have underscored the properties of aubrites. These rare space rocks, which have been named after a French village Aubres, are pale in color and contain small amounts of metal. Notably, about 80 aubrites have been discovered on Earth so far. 

How did Mercury's fragments reach Earth?

Since scientists do not have any samples from Mercury, there is no concrete evidence that the aubrites discovered on Earth really do belong to the dreaded planet. However, Cartier said that studying the fragments has revealed that their properties are similar to what Mercury might have been in its early days. Explaining how they must have landed on Earth, the expert said that after Mercury collided with a massive object, about a third of the planet's mass scattered into space and reached the asteroid belt past Jupiter to form the E-type asteroids. 

These asteroids then must have undergone collisions of their own and with contributions from the solar wind, the fragments produced post-collision might have reached planets of the inner solar system including the Earth. "I think aubrites are the shallowest portions of the mantle of a large proto-Mercury,” Dr. Cartier said as per The New York Times. “This could resolve the origin of Mercury.” This hypothesis, however, was met with some resistance as few experts argued that the aubrite meteorites indeed emerged from the E-type asteroids but these asteroids have nothing to do with Mercury.