See amazing images of the night sky and cosmos in Space.com's gallery of cosmic images posted in August 2018.
Learn more about NASA's New Horizons mission, which performed history's first flyby of the Pluto system on July 14, 2015.
The weirdly clustered orbits of some far-flung bodies in our solar system can be explained without invoking a big, undiscovered "Planet Nine," a new study suggests.
Set your timers for 10 hours, 33 minutes and 38 seconds — scientists have finally figured out how long a day lasts on Saturn, cracking a lingering mystery about the ringed gas giant.
Saturn has not always had rings — the planet's haloes may date only to the age of dinosaurs, or after it, a new study finds.
The distant object Ultima Thule spins into view in a dramatic new video captured by NASA's New Horizons spacecraft.
Solar systems are messy places, but the tools astronomers use to understand these systems can re-create that chaos with surprising beauty.
The proposed "Interstellar Probe" mission would aim to reach 90 billion miles (145 billion kilometers) from the sun, pushing the limits of engineering know-how and space technology.
Kuiper Belt objects like the one New Horizons just flew past are a dime a dozen, but scientists have detailed spacecraft observations of just three such distant, frozen worlds.
The most distant celestial object ever explored may well have moons, and astronomers are trying hard to find them.
The newest snowman-like image of Ultima Thule (2014 MU69), a pristine object from the dawn of the solar system, is already revealing insights into how planets form.
Names matter, even when they're temporary nicknames for objects 4.1 billion miles (6.6 billion kilometers) away from Earth.
Only moments before New Horizons flew by the most distant solar system object ever visited, astrophysicist and Queen guitarist Brian May released his new single based on the mission.
Ultima Thule, the weird Kuiper Belt object that NASA's New Horizons spacecraft visited in a historic flyby on Jan. 1, 2019, looks like a cosmic bowling pin, scientists say.