Last night Perseverance rover captured a set of images featuring Interstellar Comet 3I/ATLAS during the night of Sol 1642 (October 3, 2025). The images have been stacked, aligned, and annotated Simeon Schmauß. The attached animated GIF reveals a very faint smudge located in the constellation ‘Bootes’. The predicted position from Stellarium matches up with the smudge perfectly using the orbit parameters of Mars and the interstellar visitor. The comet was approximately 29 million kilometers (18 million miles) from Mars when these images were acquired.

Observations of the comet’s trajectory show that it is moving too fast to be bound by the Sun’s gravity and that it’s on what is known as a hyperbolic trajectory. In other words, it does not follow a closed orbital path around the Sun. It is simply passing through our solar system and will continue its journey into interstellar space, never to be seen again.

From telescope observations, astronomers can tell that 3I/ATLAS is active, which means it has an icy nucleus and a coma (a bright cloud of gas and dust surrounding a comet as it approaches the Sun). This is why astronomers categorize it as a comet and not an asteroid.

When it was discovered, the interstellar comet was traveling about 137,000 miles per hour (221,000 kilometers per hour, or 61 kilometers per second), the highest ever recorded for a Solar System visitor, and its speed will increase as it approaches the Sun.

Observations by the NASA/ESA/CSA JWST Space Telescope of the coma, or ‘halo’, surrounding the comet already reveal carbon dioxide, water, carbon monoxide, carbonyl sulphide and water ice being released as the comet heats up.

Credit: NASA/JPL-Caltech/ASU/Simeon Schmauß