Recent images captured by telescopes reveal that the interstellar comet 3I/ATLAS is emitting a significant jet of gas and dust directed toward the sun. This behavior aligns with typical comet activity, as explained by experts.
Discovered in late June and confirmed by NASA in early July, the comet is believed to originate from a distant star system beyond our own. Measuring between 3 and 7 miles (5 to 11 kilometers) in width, it represents the largest interstellar object detected to date and is likely the oldest, possibly dating back billions of years before the sun”s formation.
While a small group of researchers controversially suggests that the object might be an alien spacecraft observing Earth, the overwhelming consensus among scientists is that 3I/ATLAS is simply a high-speed comet behaving as expected. The recent images taken on August 2 by the Two-meter Twin Telescope (TTT) at the Teide Observatory in Spain”s Canary Islands reinforce this natural explanation.
The composite image, which combines 159 exposures of 50 seconds each, depicts the icy nucleus of 3I/ATLAS as a large black dot encircled by a bright glow. A noticeable fan-shaped disturbance in this glowing area indicates where researchers believe a large jet of material, shown in purple, is being expelled in the direction of the sun. This image was shared on October 15 on the transient object monitoring platform The Astronomer”s Telegram, although it has not yet appeared in a peer-reviewed publication.
Comets are well-known for their glowing tails made of ionized gas, which can stretch for hundreds of millions of miles away from the sun. In contrast, comet jets tend to be smaller and can indeed point toward the sun. Miquel Serra-Ricart, an astrophysicist and chief science officer at the Teide Observatory“s Light Bridges research institution, emphasized that this jet is a standard characteristic of comets.
“This is the usual,” Serra-Ricart stated. “Jets are pointing to the sunward direction and the comet”s tail is in the anti-solar direction.” As comets approach the sun, they heat unevenly, causing certain areas to warm rapidly. This heating can lead to geyser-like eruptions, propelling material away from the comet.
As the nucleus of the comet rotates, the expelled jet can appear fan-shaped, similar to formations observed in the famous naked-eye comet NEOWISE during its close encounter with the sun in 2020.
Some of the material from the jet contributes to the comet”s coma, the bright envelope surrounding the nucleus, while other particles may be directed into the tail due to radiation pressure from the solar wind. This duality allows comets to have both sun-facing jets and tails pointing away from the sun simultaneously, negating the need for any extraterrestrial technology.
It remains uncertain how far the newly identified jet extends, but Serra-Ricart estimates it may reach approximately 6,200 miles (10,000 kilometers) from the surface of 3I/ATLAS. The composition of the jet is likely primarily dust particles and carbon dioxide, consistent with observations made by the James Webb Space Telescope, which detected a large gaseous plume around the comet in August.
3I/ATLAS passed by Mars on October 3 and is nearing its closest approach to the sun, known as perihelion, on October 29. Currently located on the far side of the sun, it will not be visible from Earth again until mid-November. When it reappears, astronomers will have a unique opportunity to observe the changes in this mysterious visitor following its encounter with the sun and to assess the growth of its jet and tail.
