The First Radio Signal From Comet 3I/Atlas Ends the Debate About Its Nature

More proof has emerged to help the pure origin of comet 3I/Atlas. After a number of weeks of conspiracy theories, social media debates, and hypothesis on in style podcasts similar to Joe Rogan’s, this interstellar object continues to be a comet. The most up-to-date affirmation got here from an observatory in South Africa that detected the primary radio sign from 3I/Atlas.

But how? A radio sign? That must affirm the item is technlogical in nature, would not it? The factor is, this is not a radio sign like a transmission emitted by a spacecraft. It’s as an alternative a radio frequency sample detected by MeerKAT, a radio telescope composed of 64 antennas—every with a diameter of 13.5 meters—operated by the South African Radio Astronomy Observatory. And what did it detect? “OH absorption was detected on the 1665 MHz and 1667 MHz lines,” according to the researchers.

What MeerKAT particularly detected have been traces of radio absorption by hydroxyl radicals, that’s, OH molecules, a sample that may be according to typical comet exercise. The traces seem as absorption as a result of 3I/Atlas was very near the solar and the observing geometry favors absorption over emission. This is the phenomenon defined in WIRED a number of days in the past when the controversy about non-gravitational acceleration arose: When comets attain their closest level to the solar, they sublimate ice into area and obtain a better quantity of radiation. This additionally causes them to change their trajectory.

The hydroxyl radical (OH) can take up or emit radiation at particular frequencies (such because the 1665 and 1667 MHz traces) attributable to transitions in its vitality ranges. These OH spectral traces have been detected in nebulae, comets, and star-forming areas. OH helps astronomers map the star- and water-born areas of the universe as a result of it might probably “glow” brightly at radio frequencies beneath sure circumstances.

Is There Still Hope That It’s More Than a Comet?

The detection was doable on October 24, 5 days earlier than 3I/Atlas reached its closest level to the solar. MeerKAT tried to detect radio alerts earlier, on September 20 and 28, though it was unsuccessful. “Five weeks ago, I encouraged radio observatories like MeerKAT to search for radio emission from 3I/ATLAS given that the arrival direction of 3I/ATLAS coincided to within 9 degrees with the arrival direction of the Wow! Signal detected in 1977 at a frequency of 1.4204556 gigahertz,” astrophysicist Avi Loeb wrote in a Medium post. “In response, I was assured that 3I/ATLAS will be monitored by radio observatories like MeerKAT.”

Loeb acknowledged that “no radio detection of 3I/ATLAS has been reported so far, other than the OH absorption signal.” Of course, continued monitoring of the item would should be carried out to find out whether or not the OH manufacturing is fixed or intermittent, together with components such because the extent and construction of the tail, to succeed in extra strong conclusions about its nature.

Loeb has been has been among the many most vocal advocates the of speculation that 3I/Atlas has a technological origin. (And he has already invited Kim Kardashian to hitch his analysis workforce.). The MeerKAT findings haven’t dampened his drive to probe the comet’s nature. “On March 16, 2026, 3I/ATLAS is expected to pass within 53 million kilometers from Jupiter. At that time, the Juno spacecraft will use its dipole antenna to search for a radio signal from 3I/ATLAS at low frequencies ranging from 50 hertz to 40 megahertz,” he wrote.

Will the MeerKAT detection be sufficient to place an finish to conspiracy theories about 3I/Atlas? Likely not, and a minimum of the debates have heightened most of the people’s consciousness of and curiosity in astrophysics. In the meantime, you’ll be able to dwell the trajectory of comet 3I/Atlas right here. And remember to mark December 19 on the calendar—that is when the interstellar visitor will attain its closest level to Earth.

This story first appeared on WIRED en Español and has been translated from Spanish.