Interstellar Comet 3I/ATLAS Unveils Unusual Sunward Wobbling Jets

Interstellar comet 3I/ATLAS continues to intrigue scientists as it departs from the solar system. Recent observations unveiled unexpected behaviors in its sunward jets, revealing a wobbling structure that persists every 7 hours and 45 minutes as the comet inches closer to the sun.

Understanding 3I/ATLAS’s Wobbling Jets

The comet exhibits a unique “anti-tail,” extending approximately 620,000 miles (1 million kilometers) towards the sun. This is in stark contrast to typical comet tails, which generally point away from solar radiation. Comets are known for their tails and halos formed from dust and gas released as solar radiation heats their nuclei.

Historical Context

3I/ATLAS is only the third known object to enter our solar system from another star, following the discovery of the cigar-shaped ‘Oumuamua in October 2017 and the interstellar comet 2I/Borisov in August 2019. While sun-facing anti-tails have been documented before in our solar system, the wobbling jets observed in 3I/ATLAS are unprecedented for an interstellar comet.

Research Details

• Research conducted over 37 nights between July 2 and September 5, 2025.
• Utilized the Two-meter Twin Telescope (TTT) at Teide Observatory, Tenerife.
• Followed the evolution of the comet’s coma from a sun-facing dust fan to a defined anti-solar tail.

These changes occur due to increasing solar radiation as 3I/ATLAS approaches a close encounter with the sun on October 30, 2025, coming within about 130 million miles (210 million kilometers) of the star.

Jet Motion Observations

The comet’s jet structure was detected on 7 nights between August 3 and August 29. The observed wobble indicates that the core of 3I/ATLAS rotates once every 15 hours and 30 minutes—less than previously estimated.

Journey through the Solar System

3I/ATLAS made its closest approach to Earth on December 19, arriving within approximately 168 million miles (270 million kilometers). The comet has since been heading toward the outer solar system, and like its predecessors, it is anticipated to eventually escape our solar system altogether.

Despite its imminent departure, the scientific contributions of 3I/ATLAS are significant and are expected to leave a lasting impact on our understanding of interstellar objects.