Harvard astrophysicist suggests interstellar object shows possible signs of artificial propulsion

In a recent paper, Loeb claimed that the recorded acceleration, along with the object’s bright blue appearance, could indicate that it is an artificially constructed craft. “Alternatively, the non-gravitational acceleration might be the technological signature of an internal engine,” Loeb wrote in Medium on Friday. “This might also explain the report on 3I/ATLAS getting ‘bluer than the Sun.’”

“It could potentially be explained by a hot engine or source of artificial light,” he claimed, adding that it could be a natural signature for a comet as well.

Loeb speculated that if no cloud of gas is observed around the object when it reaches its closest approach to Earth on December 19, about 167 million miles away, he said it could suggest a "propulsion system.”

The object was discovered in July by the Asteroid Terrestrial-impact Last Alert System (ATLAS) in Chile. As the object recently came within 172 million miles of the sun, Earth’s telescopes were unable to directly measure it. Crafts orbiting the sun, however, were able to take measurements. Data from the US Naval Research Laboratory show that 3I/ATLAS brightened rapidly as it neared the Sun and appeared “distinctly bluer than the Sun."

Loeb has criticized NASA for not providing images that were taken by the Mars Reconnaissance Orbiter’s HiRISE camera when the object passed the planet in October. However, according to the New York Post, the images will not be shared by NASA until the government shutdown ends.

NASA officials have dismissed claims that the object could be artificial and reiterated their belief that it is a comet. Acting Administrator Sean Duffy said on X, “NASA’s observations show that this is the third interstellar comet to pass through our solar system. No aliens. No threat to life here on Earth.”