At nearly twice Earth's size with a denser atmosphere, this fictional world hosts creatures that dwarf anything alive today, including a structure-sized organism called the Blitz Spire.

As the peerless "Aliens" turns 40, here are 26 reasons it's still the greatest sci-fi action movie of all time.

The duo perform at Fort York & the Bentway on Sunday afternoon before the final match between Spain and Argentina ...

From The Martian to The Hunger Games, Project Hail Mary to Station Eleven, these sci-fi books have shaped the genre over the ...

Are we alone in the universe? Consider mysterious "extraterrestrial" radio signals. Unexplained gases on other planets.

Eventually, we'll launch a mission dedicated solely to studying an interstellar object. When that day comes, which one should ...

For decades, scientists have searched for worlds beyond Earth that might contain the ingredients for life, and one of the ...

Scientists say new technologies have reopened the debate over whether Mars could someday be terraformed, turning a once ...

Last year, an interstellar traveler entered our solar system. Some speculated that it was an alien spacecraft, but it turned ...

Explaining the passage of time has been a gnarly problem in physics basically forever, but physicist and computer scientist ...

This new group, which is led by Harvard professor Avi Loeb, aims to advise the Trump administration and the U.S. intelligence community, as well as to publish its findings in peer-reviewed journals ...