"The national security establishment has already been doing this for five decades but thought that no one could replicate it, ...

Captured just days after its discovery, the images offer the clearest view yet of this rare visitor from beyond our solar system. The European Southern Observatory (ESO) has captured the clearest ...

A rare visitor from another star system has been spotted. It's the interstellar comet 3I/ATLAS, and it was detected on July 1 by the NASA-funded Asteroid Terrestrial-impact Last Alert System, or ATLAS ...

This is the third time an object from outside the solar system has been found. An "interstellar object" is speeding toward the inner solar system, where Earth is located, astronomers have confirmed.

Astronomers believe they have uncovered evidence of a previously unknown ninth planet lurking in the not-too-distant reaches of the solar system. This hypothetical world, dubbed "Planet Y," could be ...

On August 25th, 2012, humanity became an interstellar species. There was no fanfare or galactic welcome party as a humble robotic probe, the Voyager 1 spacecraft, crossed an invisible threshold. It ...

The outer solar system is a vast and mysterious place that could be harboring hidden objects we know almost nothing about — from the elusive Planet Nine and baby black holes to interstellar visitors ...