Interstellar 'Spaceship Comet' 3I/ATLAS Approaches Earth Within 300 Million Kilometers

The interstellar comet 3I/ATLAS, known as the “alien ship,” has approached Earth to less than 300 million kilometers, according to a report posted on Telegram by the Solar Astronomy and Heliophysical Instrumentation Laboratories of the Space Research Institute of the Russian Academy of Sciences and the Institute of Solar-Terrestrial Physics.

Comet Crosses the 300-Million-Kilometer Threshold

On Sunday at around 07:30 Moscow time, the interstellar “spaceship comet” crossed the psychologically significant boundary of 300 million kilometers from Earth. It continues to draw closer by roughly two million kilometers each day. This convergence is driven primarily by Earth itself, whose orbital motion is currently directed almost exactly toward the point in the sky where 3I/ATLAS is traveling.

The comet, meanwhile, is moving largely along a tangent. When considered in relation to the Sun, it is already traveling outward from the solar system, even as it continues to move closer to Earth.

Four Weeks of Converging Trajectories Remain

Earth and 3I/ATLAS will remain on converging paths for almost four more weeks, until December 19, when the distance between them will reach its minimum of about 269 million kilometers. After that, the two bodies will begin to move apart in space.

Distance estimates have changed several times over the past month because the comet exhibits noticeable nongravitational acceleration, requiring frequent recalculations of its orbit. Nevertheless, the object is not expected to cross the next psychological marker of 200 million kilometers under any scenario.