New calculations by astronomers in Spain and the UK suggest that not one, but two unknown planets might exist in our solar system, beyond Pluto's orbit.
An alarm indicated a possible leak of toxic ammonia. Astronauts evacuated the U.S. side of the station. Later, NASA said the problem might have been a faulty sensor.
It was an M-class flare, and it might have produced a brief communications blackout on Monday night. But no CME - coronal mass ejection - is headed our way.
The SpaceX Dragon cargo spacecraft successfully docked with the International Space Station on January 12, bringing needed supplies to the six astronauts aboard.
Scientists measure the space-time warp in the gravity of a binary star and find the mass of a fast-spinning pulsar -- just before the pulsar disappears.