NASA releases images of comet 3I/ATLAS, rejects alien spacecraft 'rumors'

NASA released new images on Wednesday of 3I/ATLAS, an interstellar object that astronomers have determined is a comet probably even older than our solar system.

First spotted in July by an Asteroid Terrestrial-impact Last Alert System (ATLAS) telescope in Chile, its unusual trajectory indicated that it was passing through our solar system from parts unknown.

The object is only the third interstellar object ever observed by astronomers traveling through the solar system. The others were comets called 1I/'Oumuamua detected in 2017, and 2I/Borisov discovered in 2019.

Comets are small solid celestial bodies that are a combination of rocky and icy material that evaporates as they warm when getting close to a star like our sun.

The new NASA images showed 3I/ATLAS with a blurry appearance but with the clear presence of a telltale coma – the hazy cloud of gas and dust around its nucleus – and a trailing dust tail.

3I/ATLAS has attracted particular attention because of one scientist's suggestion that it is not a comet but rather alien technology due to its trajectory, composition and other factors. However, NASA dismissed the rumors, confirming it behaves like a typical comet.

"It's natural to wonder what it is. We love that the world wondered along with us," Nicola Fox, associate administrator of NASA's Science Mission Directorate, told a news briefing in Greenbelt, Maryland, referring to the comet as "our friendly solar system visitor."

"We were quick to be able to say, yup, it definitely behaves like a comet. We certainly haven't seen any technosignatures or anything from it that would lead us to believe it was anything other than a comet."

At the outset of Wednesday's briefing, NASA Associate Administrator Amit Kshatriya said, "To start with, I'd like to address the rumors" about the nature of 3I/ATLAS.

"I think it's important that we talk about that. This object is a comet," Kshatriya said. "It looks and behaves like a comet. And all evidence points to it being a comet."

Kshatriya noted that NASA missions are actively searching for signs of possible life beyond Earth, pointing to research published in September showing that a sample obtained by NASA's Perseverance rover of rock formed billions of years ago from sediment on the bottom of a lake contains potential signs of ancient microbial life on Mars.

"We want very much to find signs of life in the universe," Kshatriya said.

NASA said 3I/ATLAS poses no threat to Earth and will get no closer than about 275 million kilometers to our planet.

It is now on its way out of the solar system, according to University of Hawaii astronomer Larry Denneau, co-principal investigator for ATLAS. Its closest approach to the sun came in October, and its closest approach to the Earth will come in about a month, Denneau said.

(With input from Reuters)