‘Oumuamua: The First Interstellar Asteroid Skyrockets To Earth

Is the appropriately tiled Oumuamua the first interstellar visitor ever welcomed to our own solar system? It looks like this is the case. Ever since astronomers spotted an asteroid floating through our solar system in September this year, it’s put the sky watching community into a serious spin. While there are an estimated 750,000 space rocks somewhere in our solar system, after closer observation the team of astronomers found that this was unlike any other we’ve seen so far. The orbit of this particular object, now officially named ‘Oumuamua (meaning ‘messenger from afar’ in Hawaiian), does not match any orbits from our own solar system, therefore originating from deep space.

‘Oumuamua was initially spotted by the Pan-STARRS1 robotic telescope in Hawaii. The 400-meter oblong-shaped rock was detected flying away from the sun back into outer space at a phenomenal speed of 40,000 miles per hour, causing researchers to further investigate the provenance of this asteroid. Asteroids are born when planets are formed, meaning that the existence of this space rock tells us that there is a high likelihood of other planetary compositions similar to our own somewhere in the galaxy.

Following on from the discovery of ‘Oumuamua, the astronomy community estimate that there are up to 10,000 other similar interstellar objects passing through our solar system, each holding their own clues about the formation of planets like Earth; it is believed that this asteroid may have been formed at the same time that our solar system created planets that lie beyond the asteroid belt such as Jupiter, Saturn, Uranus and Neptune, in an explosion of large pieces of metal and dense rock.

If these calculations of our interstellar visitors are correct, up to 1,000 enter and leave our solar system every year. As the technology of telescopes and other astronomy tools continues to improve, we will be able to find smaller and harder to detect objects, and hopefully learn more about what lies beyond.


An initiative backed by billionaire Yuri Milner will use a radio telescope to listen for signals from this strange interstellar object. Mr Milner’s Breakthrough Listen programme released a statement which read: “Researchers working on long-distance space transportation have previously suggested that a cigar or needle shape is the most likely architecture for an interstellar spacecraft, since this would minimise friction and damage from interstellar gas and dust.”