91�ȱ�

Nasa scientists say they've spotted a mysterious object that's darting through space.

The object - which has been named CWISE J1249 - is estimated to be nearly 30,000 times larger than the size of Earth.

It's also thought to be moving at one million miles per hour - at that speed, you could fly to the Moon in less than 15 minutes!

In fact, it's moving so fast through our galaxy, that experts think it could break out of the Milky Way.

The discovery was made by citizen scientists working on Nasa’s Backyard Worlds project.

The project uses the public's help to find new planets and planet-like objects in the sky by studying images that have been taken by the space agency.

Whereas most stars peacefully orbit the centre of the Milky Way, a mysterious faint fast-moving object was spotted zooming out of our galaxy.

One of the people who first spotted the object, Martin Kabatnik, couldn't believe what he had seen.

He said: “I can't describe the level of excitement. When I first saw how fast it was moving, I was convinced it must have been reported already.”

Nasa then used a number of ground-based telescopes to help confirm the discovery.

After tracking the object - named CWISE J1249 - experts calculated that it's moving at roughly one million miles per hour

Astronomers are still trying to figure out what the mystery object is, but they think it could be a 'brown dwarf.'

That's the name given to objects that are too small to be stars but are larger than most planets.

However, Nasa say that no other brown dwarfs are known to be on their way out of the galaxy.

Experts also think CWISE J1249 is quite old, and is likely to have come from one of the first generations of stars in the Milky Way.