Astronomers Have Identified a Space Rock From Outside Our Solar System

In a first, scientists have shown that a mysterious object that flew by our sun last month is, in fact, not native to our solar system.

’Oumuamua, Hawaiian for “messenger” or “scout,” is similar to some of the comets and asteroids in our own solar system—a landmark finding, since it suggests that there could be many, or countless, solar systems out there containing the building blocks of life. In addition, since asteroids accumulate in space to form planets, this not-so-little emissary (it’s about 130 feet long) could tell us more about how planets elsewhere in the universe get made.

An artist’s impression of interstellar asteroid ’Oumuamua

Here’s Stuart Clark, writing for The Guardian:

It is thought to be an extremely dark object, absorbing 96% of the light that falls on its surface, and it is red. This colour is the hallmark of organic (carbon-based) molecules. Organic molecules are the building blocks of the biological molecules that allow life to function.

It is widely thought that the delivery of organic molecules to the early Earth by the collision of comets and asteroids made life here possible. ’Oumuamua shows that the same could be possible in other solar systems.

One of the teams—led by David Jewitt of the University of California, Los Angeles—that published the paper estimated how my other asteroids like ’Oumuamua are passing through our solar system right now. They’ve estimated that another 10,000 could be closer to the sun than Neptune. “If this estimate is correct, then roughly 1,000 enter and another 1,000 leave every year,” writes Clark, “which means that roughly three arrive and three leave every day.”