A newly discovered celestial object may be a starless cloud that could change how astronomers understand dark matter.

A prominent Harvard astrophysicist has claimed that a mysterious object moving through our solar system could be a nuclear-powered spacecraft. Professor Avi Loeb, director of the Galileo Project, ...

3I/ATLAS has passed its closest point to Earth, meaning we will soon lose sight of it for good. Some scientists want to send a spacecraft to chase down the alien comet — or the next interstellar ...

Those concerned that 3I/ATLAS' arrival to our solar system meant that some sort of alien invasion was imminent can breathe a ...

"These images are not just pretty." When you purchase through links on our site, we may earn an affiliate commission. Here’s how it works. It was 4 a.m. on Nov. 25 at the top of Hawaii's dormant ...

I/ATLAS is old news; NASA's discovery of the mysterious starless object Cloud 9 is rewriting cosmic theory. Here is what scientists know so far.