What conditions could lead to clashes in space? Is such a situation a given, or can conflicts be short-circuited ahead of time? Space.com asked experts for their thoughts.

If you are perplexed by reports of unidentified aerial phenomena and possible visitations of alien spacecraft, you can take action with do-it-yourself sky-monitoring gear.

Space.com caught up with NASA Planetary Defense Officer Lindley Johnson to discuss recent events and what's on the planetary-defense agenda in the coming year.

There's a rising call for "unidentified aerial phenomena" to be studied scientifically, perhaps even using satellites to be on the lookout for possible future events.

U.S. military officials have increasingly flagged a new role in guarding American assets and interests in Earth-moon space.

The Pentagon just announced the creation of a task force to analyze and understand the "nature and origins" of UFOs. Here's what the much-hyped news means.

Researchers using China's huge new FAST radio telescope are piecing together a technological strategy to carry out a major and sweeping search for extraterrestrial intelligence (SETI).

A glimpse into China's readiness to handle samples from the moon reveals steps to be taken for storage, processing and preparation of the specimens.

A new virus called SARS-CoV-2 is a coronavirus that has caused an outbreak of a disease called COVID-19. But what does that have to do with Mars?

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.