Stunning Image Shows Interstellar Comet 3I/ATLAS 'Photobombing' Distant Galaxy, Revealing Multiple Tails

Astrophotographer captures dramatic view of interstellar visitor

An astrophotographer in New Mexico has captured a striking image of the interstellar object 3I/ATLAS appearing beside the barred spiral galaxy NGC 4691, while clearly showing the comet's multiple tails.

Satoru Murata, who has collaborated on several astronomical research projects, used a 0.2-meter (0.7-foot) telescope shortly before sunrise on Nov. 16 to take the photograph. The frame reveals a green coma, a long ion tail, and the reappearance of a shorter anti-tail likely produced by dust being blown off the object's surface. Earlier reports that the comet had lost its tails were due to an optical illusion caused by the comet's viewing geometry from Earth.

Careful inspection of Murata's image also shows several small jets of gas streaming from the coma. These jets are caused by outgassing: solar radiation heats volatile ices inside the comet, forcing gas through fissures in the surface. Outgassing can impart small, non-gravitational accelerations to the object and was the origin of an erroneous claim that 3I/ATLAS had exploded.

Galaxy in the frame and public imagery

The barred spiral galaxy NGC 4691 appears in the upper-left of the photograph; it lies about 70 million light-years from Earth. Seeing the interstellar comet together with NGC 4691 prompted Murata to say on social media that the scene "really gave the impression of the object being from another world." To be clear, the comet originated in another star system within the Milky Way, not from another galaxy.

Ahead of this ground-based shot, NASA's Mars Reconnaissance Orbiter (MRO) captured higher-resolution images of 3I/ATLAS during the object's close flyby of Mars on Oct. 3. Those images were scheduled for public release on Nov. 19 after a temporary delay related to a recent government shutdown. The European Space Agency also shared Mars observations that helped refine the comet's trajectory through the solar system.

What we know about 3I/ATLAS

3I/ATLAS is the third confirmed interstellar object discovered to date. First observed in early July, it was moving toward the Sun at more than 130,000 mph (210,000 km/h). Some researchers estimate the object could be as old as ~7 billion years, suggesting it formed long before our solar system.

The comet recently emerged from behind the far side of the Sun as seen from Earth after reaching perihelion on Oct. 29. Its passage was eventful: astronomers reported an unexpected brightening and a temporary color change, along with signs of a highly irradiated surface and unusual abundances of some chemical species compared with typical Solar System comets.

These unusual traits have prompted speculation in some quarters that 3I/ATLAS could be artificial. However, the majority of the astronomical community regards the object as a natural comet. Murata emphasized this view on Instagram: "No, it's not an alien mothership, and the probability that it's any type of object created by extraterrestrial civilization is close to zero. As people have said, if it looks like a duck and behaves like a duck, it's a duck."

Observers can expect 3I/ATLAS to make its closest approach to Earth on Dec. 19, when it will be about 168 million miles (270 million km) away. In the meantime, both amateur and professional astronomers continue to study its changing appearance and await higher-definition images to better understand this rare interstellar visitor.

Credit: Photo by Satoru Murata; NASA and ESA provided supporting spacecraft observations.