New Horizons

A surprisingly gentle merger between two small primordial bodies formed the distant object Ultima Thule, a new study suggests.

Here's how to see three naked-eye planets visible in May's night sky.

Ultima Thule is lumpy, and scientists aren't sure why.

An ethereal track by Queen lead guitarist Brian May accompanies the awe-inspiring time-lapse view from NASA's New Horizons flyby of a distant solar system object.

The New Horizons spacecraft is speeding away from its recent flyby target, a distant icy space rock nicknamed Ultima Thule, but the view from Earth is only getting better.

Researchers have noted a distinct dearth of small craters on Pluto and its largest moon, Charon.

The best-ever photos of Ultima Thule have made it down to Earth, and they heighten the intrigue about the frigid and faraway world.

The final photos that NASA's New Horizons spacecraft snapped of Ultima Thule during the probe's epic Jan. 1 flyby reveal the distant object to be much flatter than scientists had thought.

Astronomers just found an asteroid that zips around the sun every 165 Earth days — the shortest year for any known asteroid.

If you don't like your local weather, perhaps you would prefer the atmosphere on Uranus or Neptune — and the Hubble Space Telescope has an update on each planet's current conditions.

'Oumuamua is long gone, but it's still leaving scientists guessing. A new explanation proposes that the strange object was a "monstrous fluffy dust aggregate" produced by a busted-up comet.

When the moon's in the sky, and Venus goes "goodbye," that's an occultation.

Pioneers 10 and 11, Voyagers 1 and 2, and New Horizons are the only spacecraft currently capable of leaving the solar system. Which one will be the next to go?

NASA's Parker Solar Probe has completed its first loop around the sun and entered the second of 24 planned orbits.