Comets-Earth collision likely as 24 stars may deflect space rocks from their actual path

Comets may come crashing on our Earth as no less than 24 stars that are heading towards our solar system may deflect the space rocks, according to scientists. These comets may collide with the Earth in the next million years, Researchers at Max Planck Institute for Astronomy in Germany have said.

The stars stray into the Oort cloud and researchers calculated how often they visit there. Oort cloud is a vast, spherical shell comprising of billions of icy objects that is believed to envelop our solar system.

According to researchers, such close encounters can displace these comets, pushing them into the solar system and thus causing a risk of a collision course with the Earth.

Within the next million years between 19 and 24 stars will come within 3.26 light years of the Sun, the team predicted, saying they will be close enough to deflect comets from their original paths.

"Certainly anything coming within that distance you should worry about," Coryn Bailer-Jones, of the Max Planck Institute was quoted as saying by The Guardian.

However, they said that not all close encounters would result in comets hitting the Earth. The collision would depend on the position of the Earth in its orbit relative to the passing star. However, chances of collision would peak at these time points, they said.

Researchers said that the paper predicts that a further estimate 490 to 600 stars will pass close to the sun within a distance of 16.3 light years within the next million years. 

This is far beyond the predicted outer reaches of the Oort cloud, but in the case of a very large star, still potentially close enough to cause comets to swerve in their tracks, they added.

The study was published in the journal Astronomy and Astrophysics.

ALSO READ | NASA scientist warns surprise comet or asteroid may collide with Earth and humans not prepared for it