The object 3I/ATLAS has performed a maneuver as it approaches the Sun, demonstrating the first evidence of non-gravitational acceleration, according to a report from NASA's Jet Propulsion Laboratory.
„The radial acceleration from the Sun is 135 kilometers (=9x10^{-7} AU) per square day. The transverse acceleration relative to the Sun is 60 kilometers (=4x10^{-7} AU) per square day“, the report says.
This unusual maneuver was recorded at a distance equivalent to 203 million kilometers.
Harvard University scientist Avi Loeb suggested that an unknown force was acting on the space object, causing it to deviate from its trajectory as it approached the Sun. He also suggested that ATLAS could be propelled by jet propulsion.
If so, the scientist explained, the object would lose half of its mass over a period of time.
“Such a colossal loss of mass should be detectable as a large gas cloud around 3I/ATLAS in November and December“, he concluded.
The interstellar object 3I/ATLAS was discovered on July 1. Scientists later determined that it was a comet from another star system. The cloud of gas and dust around its nucleus is approximately 24 kilometers in diameter. A computer model estimated its age at over seven and a half billion years - three billion years older than the Sun. This may be the oldest comet ever observed.
In September, Avi Loeb reported that the interstellar object 3I/ATLAS, while passing through the Solar System, had undergone an “anomalous evolution“, starting to change its color. In August, the scientist reported that 3I/ATLAS was emitting its own light, similar to the glow of car headlights, although the source of the glow was not identified. He suggested that 3I/ATLAS might be an artificial object with a powerful energy source capable of generating light visible from millions of kilometers away.