Is time travel possible? Are the past and future set or can they be changed? Sci-fi books and films have long explored these ideas.
In the film "The Martian" (2015), an astronaut played by Matt Damon has to improvise when his crew leaves him behind by accident. Here's a look at what Watney would need to stay alive on Mars.
After decades of speculation, scientists now know for sure that liquid, salty water flows on the surface of Mars. See what the discovery means in our infographic.
A series of four total lunar eclipses in a row is called a tetrad, or four Blood Moons. See how lunar eclipse tetrads work in this Space.com infographic.
Daredevil sungrazing comets risk annihilation every time they skim the surface of our star. Here's how the Solar and Heliospheric Observatory tracks these comet interlopers.
Amazon founder Jeff Bezos leads Blue Origin, a commercial aerospace firm that hopes to send people on suborbital and orbital space trips.
How Solar Eclipses Work: When the moon covers up the sun, skywatchers delight in the opportunity to see a rare spectacle.
A planet only 20 million years old and still hot from its creation has been photographed in a solar system 96 light-years from Earth.
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