The great distances covered by visiting "aliens" may be ones of time rather than space, a recent book argues.

An unidentified astronaut aboard the International Space Station had a deep vein thrombosis — or blood clot — in the jugular vein of their neck, according to a new case study.

China's farside rover, Yutu 2, has broken the longevity record for working on the surface of the moon.

Is 2020 the celestial payoff year, in which astronomers finally confirm a "technosignature" coming from an advanced alien civilization?

See the moon through the eyes of the legendary moonwalker for the first time.

We still don't know what the X-37B is doing up there, however.

The UFO-investigating group MUFON turns 50 next month. What have we learned over the past five decades?

The Soviet Union launched the Cosmos 482 Venus probe on March 31, 1972. But the failed Venus craft is crashing back to Earth soon.

The secretive mission of a U.S. Air Force X-37B miniature space plane just winged past 500 days in Earth orbit.

The latest mystery mission of the U.S. Air Force's robotic X-37B space plane has now passed the 400-day mark.

China’s Tiangong-1 space lab will likely fall to Earth between March 30 and April 2, according to the latest prediction by the European Space Agency’s (ESA) Space Debris Office in Darmstadt, Germany.

NASA's Mars rover Curiosity has found intriguing structures on Mars that look like tiny, fossilized worm burrows — but mission team members aren't claiming that the finds are evidence of life.

Communication between Earthlings and intelligent aliens should be based on mathematics — exo-arithmetic greetings that form a shared lingo, some researchers say.

Astrobiologists ponder sending gene sequencers, weather stations, drilling rigs and more to the Red Planet

A new plan for the "terraformation" of Mars has been scripted by a research team – a blueprint for the red planet to terraform a site on Mars in 2036.

The U.S. Air Force's mysterious X-37B space plane has now spent 600 days in Earth orbit on the vessel's latest mission and is nearing a program record for longest time spent in space.

China's Information Office of the State Council on December 27 released an expansive white paper on that country's space activities in 2016, and projected looks at its space agenda in coming years.

The envisioned colony will be a permanent base for science, business, mining and even tourism on the moon, European Space Agency officials said.

More than 20,000 newly released documents reveal intriguing details about the U.S. Air Force's MOL program, which ran from December 1963 until its cancellation in June 1969.

Mum's the word: The secretive X-37B space plane has winged its way past the 200 day mark, carrying out a classified agenda for the U.S. Air Force.

Lunokhod 1 last trekked across the lunar surface more than four decades ago.