Mystery alien object spotted passing through Solar System

A mystery alien object that has come from interstellar space has been spotted travelling through the Solar System.

The object, thought to be about 12 miles in diameter, is likely to be a comet or asteroid and is heading towards the Sun.

It is only the third time that an interstellar object has been seen inside the Solar System and experts are hoping it might give clues about alien star systems.

The object, originally called A11pl3Z and now known as 3I/Atlas, will make its closest approach to the Sun about Oct 30 but amateur astronomers on Earth should be able to pick it up from August.

The object was discovered by amateur astronomers at the Asteroid Terrestrial-impact Last Alert System (Atlas) – a network of four telescopes in Hawaii, Chile and South Africa – which was set up to give an early warning of dangerous asteroids.

Nasa confirmed the object poses no threat to Earth and will remain at a distance of about 150 million miles.

Current estimates show that it will get about 40 per cent further from the Sun than the Earth is, before heading back out into the galaxy.

Dr Mark Norris, a senior lecturer in astronomy at the University of Central Lancashire, said: “If confirmed, it will be the third known interstellar object from outside our Solar System that we have discovered, providing more evidence that such interstellar wanderers are relatively common in our galaxy.

“As it gets closer, it’s expected to brighten, especially if it turns out to be a comet rather than an asteroid. By the time it makes its closest approach, it will be a relatively easy target for amateur astronomers to observe.

“Even with our fastest rockets, it would take tens of thousands of years for us to reach nearby stars. Thanks to these visitors from outside our Solar System, we may not have to travel that far to sample star systems beyond our own.

“They might hold vital information about the building blocks of planets, or even life elsewhere in the universe. But to unlock those secrets, we’ll need the technology to catch up and reach them before they pass through our Solar System.”

The object is arriving from the direction of the constellation Sagittarius, and is currently located about 420 million miles from Earth.

Astronomers realised that the object was unusual because of its strange hyperbolic trajectory through the Solar System. The curve of its orbit is so flat and far away from being a circle that it must have come from interstellar space.

Only two other interstellar objects have been spotted in our Solar System previously.

The first, called Oumuamua (pronounced oh MOO-uh MOO-uh) was a bizarre cigar-shape rock, which passed through the Solar System in 2017 and appeared to be accelerating away from the Sun, suggesting it had an internal power source.

Some speculated it might be an alien spacecraft, but scientists later found its course was being altered by the tiny push created as hydrogen gas spurted out of its icy surface, acting like a thruster.

The second was 2I/Borisov, a comet which was spotted in 2019 and thought to have originated near to a red dwarf star.

The new space rock is currently very dim but amateur astronomers with sensitive equipment may still be able to capture it using a long exposure.

Next month the new comet should become brighter allowing more astrophotographers to capture on camera the rare visitor.

Experts say it should remain visible to ground-based telescopes through September, after which it will pass too close to the Sun to observe, but will reappear in early December.

The European Space Agency said its Planetary Defence team were continuing to observe the object.

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