Arizona's dark skies are a haven for astronomers and photographers. Some communities are fighting to keep them that way.

In January 2025, Venus, Mars, Jupiter, Saturn, Uranus and Neptune were all visible in the night sky. And in February, 2025, ...

An amateur astronomer discovered Pluto 95 years ago today. The former planet will complete an orbit in another 153 years.

The controversy endures over Pluto's true status, but the solar system underdog continues to capture hearts across the globe.

Updates on Asteroid 2024 YR4 have been slower during the full Moon, but experts say the precision of the object’s orbit is ...

Clyde Tombaugh discovered Pluto in 1930 at Lowell Observatory in Flagstaff. Here's how Pluto won - and lost - its planetary status.

Pluto may not be a planet any more, but you still have a chance to see the distant dwarf planet at one of Michigan's ...

“New Horizons shattered a major paradigm of planetary science,” says Alan Stern, the mission’s principal investigator. “Pluto ...

The annual event celebrates the discovery of the little planet with a big heart and other scientific advances at Flagstaff, ...

On today’s date 95 years ago, everyone’s favorite not-quite-a-planet, Pluto, was discovered by astronomer Clyde W. Tombaugh ...

Feb. 18 marks the 95th anniversary of the discovery of our outermost planet-not-planet. Here's what to know about the short ...

Trans-Neptunian objects (TNOs) are icy bodies that vary widely in size, from large dwarf planets like Pluto and Eris—each ...