NASA has confirmed a small extra 'kick' moving the mysterious visitor dubbed 3I/ATLAS off its predicted path, which can't be explained by the sun's gravity.

The sun contains almost all of the solar system's mass, meaning its weight pulls all the planets together in a predictable motion scientists can measure, but these new movements by 3I/ATLAS appear to defy our laws of gravity.

The object, which many scientists claim is a comet, set a record as the fastest space rock entering the solar system ever detected by humans at more than 130,000mph.

After reaching its closest point to the sun on October 29, known as perihelion, its speed has now soared to approximately 152,000mph.

While NASA believes the sun's gravity is mainly responsible for the speed boost, scientists are having a harder time figuring out what has caused 3I/ATLAS to noticeably shift away from our home star.

If it were an ordinary comet, the heat of the sun would be causing the icy cold space rock to melt and shoot out jets of gas trapped inside, potentially pushing the comet in a different direction.

However, Harvard physicist Avi Loeb has revealed that astronomers are still awaiting evidence that 3I/ATLAS has released anywhere close to enough gas to prove the object is really a comet.

3I/ATLAS is now just six weeks from reaching its closest point to Earth, and Loeb added that not detecting a cloud of gas coming from the object would be a clear sign that this latest speed boost was powered by an extraterrestrial rocket engine.

NASA's latest readings found the mystery push got significantly weaker in the days after 3I/ATLAS reached its perihelion with the sun, but it was still noticeable and unrelated to the star's gravitational pull.

For a natural space rock to pull off this strange maneuver, scientists examining the NASA data have estimated that 3I/ATLAS would have had to suddenly lose at least 13 percent of its total mass as it approached the sun.

That's the only way enough of the comet would have been transformed into a gas that blasted the object away like a thruster on a spacecraft.

If this happened while 3I/ATLAS was hiding in the sun's blind spot from our viewpoint on Earth, a huge cloud of dust and gas from that event would have formed around the rock.