Europa has an ocean, hidden beneath its icy crust. The discovery of sodium chloride - aka table salt - on the moon's surface might be strong evidence that Europa's ocean is very similar to Earth's.

A new study suggests that many exoplanets - worlds orbiting distant stars - might have an overabundance of toxic gases in their atmospheres. If so, that would make the evolution of complex life forms more difficult.

Liftoff is targeted at 11:30 p.m. EDT, with a 4-hour launch window. SpaceX is calling the launch its most difficult ever, because the rocket must release 24 satellites into 3 different orbits.

Scientists have discovered a massive subsurface deposit of dense material - probably metal - beneath the largest crater on the moon. Did it result from a huge asteroid impact or a former lunar ocean of molten rock?

New research suggests that superflares - massive bursts of energy from a star's surface - can happen on stars like our sun. What might that mean for us on Earth?

The Mars Helicopter will launch with Mars 2020. It'll be the first vehicle in history to attempt to establish the viability of heavier-than-air vehicular flight on another planet. Plus ... space engineers celebrate with a selfie after attaching the Mars 2020 rover's remote sensing mast.

People have reported seeing Transient Lunar Phenomena - unusual flashes and other lights on the moon - for at least 1,000 years. Yet they're still mysterious. Now a scientist in Germany is using a new telescope to try to solve the mystery.

The American Astronomical Society - chief organization for US astronomers - said it is in conversations with SpaceX about the impending launch of 12,000 Starlink satellites. The astronomers worry the satellites will interfere with their work of understanding the universe.

Nearly 100 countries have already signed up to organize national campaigns, to provide the public with an opportunity to vote. The deadline is July 30 to express interest in organizing a national campaign. The IAU will announce results in December.

The search for life on Mars usually involves looking for past or present microbes, invisible to the eye. Scientists at University of Illinois suggest searching instead for a type of rock formation known on Earth to be created by microbes.