Scientists baffled by 'interstellar object' spotted hurtling towards our solar system

A mysterious object from outside our solar system has just been spotted by astronomers heading towards our planet.

Harvard physicist Avi Loeb revealed that the object is expected to pass by Earth on December 17, speeding through the solar system at more than 41 miles per second (roughly 150,000 miles per hour).

That means the unidentified object, which scientists are calling A11pl3Z, is moving too fast for it to get caught in the gravitational pull of our sun or any other planet.

A11pl3Z's unusual course and speed was first spotted by astronomer Sam Deen in late June, however, it has just been flagged by the International Astronomical Union after its interstellar origins were confirmed.

Loeb believes A11pl3Z could be a large space rock or a comet, but astronomers are still figuring that out.

It's estimated to be about 12 miles wide. That makes it much larger than the last two otherworldly objects that flew through our solar system, Oumuamua and the comet Borisov.

Oumuamua was only about 300 to 1,300 feet long and Borisov's core was about half a mile in diameter.

Like Oumuamua in 2017, A11pl3Z could soon start stirring more speculation that the object is man-made and sent here from another solar system with intelligent life.

In 2021, Loeb, the Frank B. Baird Jr. Professor of Science at Harvard, theorized that Oumuamua could have 'been meant to scan signals from all viewing directions,' looking for sensors from a long-lost receiver previously placed on Earth.

The first recorded interstellar object set off alarm bells among UFO researchers after scientists discovered Oumuamua was not a known comet or asteroid.

'It was inferred to have a disk-like shape and to exhibit non-gravitational acceleration, raising the possibility of an artificial origin,' Loeb wrote in an article on Medium Wednesday.

If A11pl3Z is a space rock, it's surprisingly massive compared to the other two interstellar objects that have passed by Earth.

However, scientists don't project that the mystery object will get anywhere near Earth. On its current trajectory, it'll come within 2.4 astronomical units of the planet (223 million miles).

An astronomical unit (AU) is equal to the distance between Earth and the sun, 93 million miles. Technically, A11pl3Z is already in the solar system, and is currently 3.8 AU away from Earth as of July 2.

In October, the object from outside the solar system is expected to make its closest pass to a planet, coming within 0.4 AU (37 million miles) of Mars.

Scientists don't believe A11pl3Z poses any threat to Earth. At 12 miles in length, that's good news because the object would fall into the category of a 'planet killer' - likely causing an extinction-level event if it struck the Earth.

However, there is a chance that A11pl3Z is not as big as it currently appears. Loeb explained that the interstellar visitor could be a comet, just like Borisov in 2019.

The physicist said that it could have a smaller core surrounded by a bright cloud of gas and dust. This would reflect sunlight and make the mass appear larger to our telescopes.

A11pl3Z's extreme speed will only give astronomers a short window to study the mysterious object before it leaves the solar system in 2026.

In that time, scientists will look to gather information on its trajectory using telescopes like the Rubin Observatory in Chile, and possibly the James Webb Space Telescope in space. 

They'll hope to confirm A11pl3Z is staying on its expected route, passing the sun in later October, swinging by Earth at a safe distance in December, and then flying past Jupiter in March 2026.

Once it gets closer, scientist should be able to determine what A11pl3Z actually is - an asteroid, a comet, or something else entirely.

Mark Norris at the University of Central Lancashire told New Scientist: 'They really do whip through the solar system at ridiculous speeds. They're really fleeting and you are severely limited in what you can learn about them.'