Solar system

Our galaxy and its nearest large companion, Andromeda, may be headed for a collision on a cosmic scale. What happens then?

The asteroid will swing by Earth on Monday and be close enough to be visible using an amateur telescope

The rare isotope helium-3 is one of Earth’s most precious commodities—so precious, in fact, that it might prove profitable to mine from the moon

NASA’s moon exploration plans call for nearly 80 launches, nearly 75 landers, 10 moon buggies and one nuclear reactor

Lindy Elkins-Tanton, principal investigator of NASA’s Psyche mission, explains in her new book how lessons from interplanetary exploration can help people solve problems together

The problem with Pluto isn’t its planetary or nonplanetary status—it’s our insistence on declaring the world must be one or the other

An almost unkillable fungal strain isolated from NASA’s ultrasterile clean rooms hints at “critical gaps” in interplanetary quarantine

The Kardashev scale is an interesting but flawed gauge of a civilization’s growth

The NASA administrator’s latest remarks in support of reexamining Pluto’s status come 20 years after the orb was downgraded to a dwarf planet by the International Astronomical Union

Rather than slowly condensing over millions of years, the first building blocks of Earth and other planets may have formed rapidly in a chaotic disk at the dawn of the solar system

All the sun’s planets are oddballs. But some are more so than others

After all these years, Dream Chaser—a commercial U.S. space plane—is still chasing the dream of spacecraft that can fly from orbit to airports