How big would a telescope need to be to see Earth’s dinosaurs from 66 million light-years away? Think big—and then think ...

Astronomers are closing in on what looks like a rare prize: a world almost the size of Earth, circling a Sun-like star at a distance that gives it a familiar, year-long orbit. The candidate, known as ...

A 'potentially hazardous' asteroid the size of a pyramid will skim past Earth tomorrow, NASA has revealed. The asteroid, called 2014 TN17, is expected to come as close as 0.03404 astronomical units, ...

CAPE CANAVERAL, Fla. -- For the first time ever, astronomers have discovered seven Earth-size planets orbiting a nearby star - and these new worlds could hold life. This cluster of planets is less ...

A NASA mission has spotted an Earth-size exoplanet orbiting a small star about 100 light-years away. The planet, named TOI 700 e, is likely rocky and 95% the size of our world. The celestial body is ...

Add Yahoo as a preferred source to see more of our stories on Google. White dwarf stars, like this one shown shrouded by a planetary nebula, are much smaller than stars like our Sun. NASA/R. Ciardullo ...

the Earth you walk on today might not be the same planet that was born 4.5 billion years ago. Many scientists believe that in its infancy, Earth collided with another world the size of Mars, and that ...