Sarah Lewin

Researchers have identified a sixth planet orbiting the first star system discovered by the crowdsourcing project Exoplanet Explorers, a system with a unique resonance.

The free Pluto Safari app let New Horizons fans track the probe's flyby of Pluto in 2015, and now it's set to follow the journey past the distant body Ultima Thule on New Year's Day.

A newly discovered object is the most-distant body ever observed in the solar system — and the first object ever found circling at more than 100 times the distance from Earth to the sun.

NASA's new Mars lander isn't quite ready to probe the Red Planet's interior yet, but it's starting to get the lay of the land on the surface — and in the atmosphere.

The Geminid meteor shower will provide a shining backdrop for the approach of Comet 46P/Wirtanen on Thursday (Dec. 13), shortly before the object's closest approach to Earth in 20 years.

Head for dark, clear skies tonight — overnight Dec. 13-14 — to see the shooting stars of the Geminid Meteor Shower overhead.

SpaceX's Dragon spacecraft lifted off into clear blue skies today (Dec. 5), but its first stage spiraled down in a failed landing.

NASA astronaut Nick Hague is set for a second chance at his first trip to orbit.

There will be 36,000 worms heading to space Dec. 4 — and, if all goes well, 2 million to 3 million will come back down.

During its full first day on Mars, NASA's solar-powered InSight lander generated more electrical power in one day than any previous Mars vehicle has, mission team members said.

NASA's InSight Mars lander arrives at the Red Planet today, and NASA will offer live 360-degree views inside its mission control center when it happens.

NASA’s InSight lander is set to touch down on Mars this Monday (Nov. 26). Why do we keep sending robots to the Red Planet?

Monday evening (Nov. 19), National Geographic will air a 1-hour special about Parker Solar Probe, the record-breaking mission currently slinging around the sun.

Why haven't we heard from aliens? Scientists don't know, but they have a couple of ideas.

Retired NASA astronaut Scott Kelly has released a photobook, "Infinite Wonder," chronicling his 340 days on the International Space Station. Here are some selections from Kelly's time there.

The "Ghost of Cassiopeia," a slowly eroding cloud of gas and dust, forms a glimmering haze in this eerie image from the Hubble Space Telescope.

In his new book "Astounding," coming out today (Oct. 23), Alec Nevala-Lee follows four titans of the golden age of science fiction who guided the genre during its formative years.

Alec Nevala-Lee's latest book "Astounding," out Oct. 23, chronicles the interwoven lives of four science fiction titans: Isaac Asimov, Robert Heinlein, L. Ron Hubbard and John Campbell.