Arizona stargazers, mark your calendars because on Friday, Sept. 19, the night sky will host a celestial conjunction. Not to be confused with an alignment, a conjunction occurs when two or more ...

On August 24, 2006, our solar system lost a planet. It wasn't by cataclysmic destruction, but rather by the vote of the International Astronomical Union, which declared that Pluto, considered the ...

The universe has quasi-moons, mini-moons, and moonlets, but no official definition of what counts as a moon.

Saturn is the planet of discipline, boundaries and structure — its influence will challenge you to grow. Here's everything ...

It's an evocative idea that has long bedeviled scientists: a huge and mysterious planet is lurking in the darkness at the edge of our solar system, evading all our efforts to spot it. Some astronomers ...

Mike Brown is convinced that beyond Neptune, at the far reaches of our solar system, there's an unseen giant planet. "This is the 5th largest planet in our solar system, lurking out there, waiting to ...

In a startling new observation, the James Webb Space Telescope (JWST) has detected a planet with an atmosphere made almost ...

Astronomers using the James Webb Space Telescope have made the first 3D map of an alien planet's atmosphere, revealing ...

Scientists from the University of Cambridge announced this week what they believe is the strongest evidence so far of extraterrestrial life. The place in question is not within our solar system, but ...

A celestial conjunction featuring the moon, Venus, and the star Regulus will be visible on Friday, Sept. 19. This event will be bright enough to be seen without a telescope, though clouds could ...