Asteroid Enters the Solar System

For the first time ever, astronomers have discovered an alien guest – a fast-moving asteroid – in our Solar System. In the future, telescopes will track any other space rocks passing by.

ASTRONOMY For years, astronomers believed that asteroids from other solar systems were able to pass into our Solar System. But it was only recently that the theory was proved, when astronomer Rob Weryk from the US University of Hawaii spotted a bright dot in the sky, which he had never observed before.

The bright dot proved to be an asteroid, which was briefly passing by from another solar system. Scientists have calculated that the asteroid sped almost vertically down through the Solar System – instead of following a flatter path like other asteroids.

The Sun’s gravitational field made the asteroid take a hairpin bend only to eventually disappear in the direction of the Pegasus constellation.

Astronomers measured the asteroid’s eccentricity, which describes how circular its path is. 0 indicates a perfect circle, whereas 1 is elliptical. The visiting space rock was estimated to be 1.9, so its form is extremely elongated.

The interstellar guest has a diameter of 400 m and has been named A/2017 U1. According to astronomers, the rock has travelled for millions or billions of years.

Ongoing observations will show if the asteroid was alone or accompanied by other space rocks.