Add Yahoo as a preferred source to see more of our stories on Google. This video takes viewers on a long journey from the diminutive Speck of Horton Hears a Who (diameter 0.9 mm) all the way up to the ...

There’s something about comparing the sizes of unthinkably large objects that’s endlessly intriguing. Looking at a comparison of all the various sizes of stars in the universe, for example, makes for ...

Scientists have discovered over 4,000 exoplanets outside of our Solar System, according to NASA’s Exoplanet Archive. Some of these planets orbit multiple stars at the same time. Certain planets are so ...

NASA's leading planet-hunting spacecraft has spotted its second planet that matches Earth's size and may be able to retain liquid water — and both worlds orbit the same star. NASA's Transiting ...

Want to know how the Millennium Falcon compares in size to an Imperial Star Destroyer? Just watch a Star Wars movie. But if you want to know how that hunk of junk compares to the Battlestar Galactica, ...