“What keeps me up at night is the asteroids we don’t know about," said NASA's planetary defense chief.

NASA astronaut Zena Cardman shared timelapse footage of Earth from space after returning from a mission aboard the ...

Astronomers do not know where thousands of “city-killer” asteroids are, Nasa’s head of planetary defence has admitted.

NASA officials warn thousands of undetected “city killer” asteroids may be circling near Earth. With limited deflection tools ready, are we prepared if one suddenly shifts onto a collision course?

The object is hurtling towards the Earth at a zippy 12,616 miles per hour, according to data from the space agency.

Imagine a rock the size of a football stadium hurtling through space at thousands of miles per hour, heading straight for a major city, and we have no way to stop it. NASA has just issued a sobering ...

"We don’t know where they are,” said NASA’s planetary defense officer Kelly Fast at the AAAS conference in Arizona this week.