Charles Q. Choi

In the wisp-thin sky of Jupiter's moon Ganymede, the largest satellite in the solar system, astronomers have for the first time detected evidence of water vapor, a new study finds.

Mysterious flares of X-rays from Jupiter's auroras suggest that the giant planet's "northern lights" may possess unexpected similarities with those of Earth, a new study finds.

A cluster composed of thousands of stars may dissolve to become a mob of dozens of black holes in a billion years.

Mysterious human may have been the ancestor of Neanderthals.

Tendrils of galaxies up to hundreds of millions of light-years long may be the largest spinning objects in the universe, a new study finds.

Boulders on asteroids can be three-quarters hollow or more, a discovery that could help yield insights on the way in which Earth and other planets formed, a new study finds.

A UN report suggests that AI drones attacked human targets without any humans consulted prior to the strike.

Evidence of what may be the youngest eruption seen yet on Mars suggests the Red Planet may still be volcanically active, raising the possibility it was recently habitable.

Cats like boxes so much, they will even climb into the illusion of a box, scientists find.

When a white dwarf star explodes as a supernova, it may be detonating like a nuclear weapon on Earth, a new study finds.

The first known interstellar comet to visit our solar system may be the most pristine ever found, never passing near a star until visiting our own, researchers say.

What might life be like then if everyone lacked an appendix? That organ may not be a useless artifact of evolution after all.

Oceans' worth of water may remain buried in the crust of Mars, and not lost to space as previously long thought, a new study finds.

Temperature-dependent sex is found in certain reptiles and fish. Could it happen in humans?

The haze shrouding Pluto might be made up of ice crystals possessing cyanide hearts, a new study finds.

If humans had green skin, for instance, what if it granted us the ability to perform photosynthesis, which plants use to live off of sunlight?

Earth is the only planet traveling within its nearly circular orbit around the sun. But what if Earth shared its orbit with another planet?

What might the world be like if everyone on Earth had albinism, from prehistoric times until now?

A viable nuclear fusion reactor — one that spits out more energy than it consumes — could be here as soon as 2025.

Remnants of water once found on the surface of Mars may be hidden in a handful of small lakes below the Red Planet's south pole, and more could exist, according to new research.

Unusual flashes of gamma rays could reveal that what appear to be giant black holes are actually huge wormholes, a new study finds.

What might Earth be like crowned with rings? Space and science- fiction illustrator Ron Miller created extraordinary images of how the sky might look if Earth possessed such rings.

Will the majestic redwoods of California's coast survive the lightning-sparked fires raging across the state?

Astronomers might detect black holes falling into wormholes via ripples in space-time called gravitational waves, a new study finds.

Scientists have generated an exotic form of matter in the unique microgravity environment aboard the International Space Station and are using it to explore the quantum world, a new study finds.