Professor Avi Loeb, a theoretical physicist and cosmologist from Harvard University, told MailOnline why he thinks a new interstellar object is really an alien craft.

Over the next few days, astronomers will pull together evidence to determine whether the object is a comet.

An "interstellar object" is speeding toward the inner solar system, where Earth is located, astronomers have confirmed.

The ultra-rare object is travelling at about 245,000 kilometres an hour and will fly deep into the solar system, skimming past Mars.

Until now, astronomers had only spotted two confirmed interstellar objects. The first was ‘Oumuamua, a small, cigar-shaped object that visited our solar system in 2017.

A mysterious visitor from another solar system could be an alien spacecraft, according to a leading Harvard astronomer.

NASA scientists have confirmed that a mysterious object shooting toward us through the solar system is an "interstellar object" — only the third of its kind ever seen.

Astronomers have discovered a new object that originated outside of our Solar System — only the third to be found.

Astronomers on Wednesday confirmed the discovery of an interstellar object racing through our solar system—only the third ever spotted, though scientists suspect many more may slip past unnoticed.

The harmless object is currently near Jupiter hundreds of millions of miles (kilometers) away and moving toward Mars, but it should get no closer to the sun than that, according to scientists. It’s ...

Astronomers are monitoring an object headed our way that may have wandered over from another star system. Scientists have discovered what might be only the third known interstellar object to pass ...