'Potentially hostile alien threat' pictured as interstellar object officially declared a 'threat'

The 'potentially hostile alien threat' that scientists have deemed to be a comet from outside our solar system has officially been listed as a threat by a group that focuses on planetary defences.

Ever since it was first spotted in July, 3I/ATLAS has sparked debate among the space community as to what the object is due to its unusual behaviour.

While many were quick to suggest the interstellar object must be some kind of alien spacecraft, it has officially been labelled as a comet, despite not everyone being in agreement.

Harvard professor Avi Loeb remains convinced there's more to the object, and recently suggested there was still a 30 to 40 percent chance 3I/ATLAS is not a naturally formed object.

Now it seems like NASA has been quietly making moves to put protections in place after the International Asteroid Warning Network (IAWN) added the comet to its list of threats.

3I/ATLAS captured by the Hubble Space Telescope in July (NASA)

This is the first time the UN-backed group has even added an interstellar object to its list, as they move to improve detection skills for space objects while preparing the planet for any potential associated threat, the Mail reports.

Earlier this week, the IAWN said 3I/ATLAS was causing 'unique challenges,' when it came to predicting its path, prompting the decision to add it to its Comet Astrometry Campaign.

One of the things that has been baffling scientists most about the extraterrestrial object is that it appears to have an 'anti-tail' of jet particles, which point to the sun instead of away from it, as you'd typically expect from a comet.

According to Loeb, 3I/ATLAS appeared to show a tail reversal, which he believes is a move that is reminiscent of an ‘alien spacecraft’ braking. This later switched to the kind of tail you'd expect from a comet.

"We cannot infer the true nature of 3I/ATLAS from the skin layer it has shed so far," he said.

The object has been showing dramatic colour variations (NASA)

"If the object were an alien spacecraft slowing down, and the anti-tail represented braking thrust, this shift from anti-tail to tail would be entirely expected."

Not only that, the object also appears to show dramatic colour variations, as well as an enormous surrounding coma, which is a cloud of gas and dust around the nucleus.

He explained that in spaceflight, the optimal moment to accelerate or decelerate a spacecraft is when it is nearest to a massive object, as firing the engine at that point - known as the Oberth effect - produces the greatest change in velocity.

"If 3I/ATLAS is a massive mothership it will likely continue along its original gravitational path and ultimately exit the Solar System," the scientist added.

"In that case the Oberth manoeuvre might apply to the mini-probes it releases towards Solar system planets."