The answer has been debated for a long time, and using different techniques, has wavered between 500 million years ago to almost 1.5 billion years ago.
Humans settling Mars or living in a space colony might evolve into a new species much faster than they would have on Earth, assuming they can avoid the dangers of inbreeding.
Jupiter has such powerful auroras because they come from volcanoes erupting on its moon Io, rather than the sun’s storms that create northern lights on planet Earth.
A new telescope is trained on the moon to capture meteors crashing as part of an effort to understand asteroids and other space rocks that could strike Earth.
Scientists figured out how old beetle fossils were to learn about the prehistoric climate of Los Angeles, and it looks like it was the same as it is today.
A couple of average Joes helped scientists find a supernova, an exploding star so bright that it casts light upon the universe and shows us the answers to its biggest mysteries.
NASA launched some student-designed Mars rover robots into space on a rocket to see how well they would travel in Earth’s atmosphere.
Earth was really hot when it was younger, but a recent lava and rock analysis suggests that it’s still bringing the heat deep down in its mantle.
New Zealand is hoping to send a rocket into space every week, carrying satellites into low-Earth orbit and joining the other countries that have launched into the atmosphere.
Black holes are notorious serial starkillers, so good at what they do that we don’t even have photos of them, just the NASA version of police sketches.
The rivers on Titan, Saturn’s biggest moon, flow across its landscape the way they used to on Mars before it dried up, so Titan may not be as similar to Earth as we thought.
Comets may have delivered Earth’s atmosphere while it was forming and made it the planet we love today.
Humans affected space weather, in a way usually reserved for the sun when the U.S. and the Soviet Union exploded nuclear bombs in the atmosphere during the Cold War.
A human space colony on Mars or another planet may evolve into a different race if we leave inhabitants alone to breed.
Young Earth did not have the surface shape it has today. Scientists say it was probably pretty flat and almost completely covered in ocean.
NASA is testing its new telescope in a frigid vacuum to prep it for launch and its search for aliens on planets in other solar systems.
Researchers from McGill University in Canada argued in a new study that the silica-rich minerals in Earth's crust may have been deposited by a “silicate rain.”
The Mars rover Curiosity is carrying dirt in its hand as it scales a mountain and continues exploring another planet.
Jupiter’s enormous swirling red storm, its Great Red Spot, is shrinking so much that it is changing shape and could soon be the size of Earth.
Stephen Hawking says humans have to leave Earth in the next 100 years and colonize another planet if we want any hope of surviving extinction.
When NASA’s Cassini spacecraft went on a dive between Saturn and its rings, scientists heard whooshes and squeaks instead of pops and cracks, showing that the gap is emptier than they expected.
Life adapts and survives in even the most unforgiving environments on Earth.