On Valentine's Day 1990, NASA's Voyager 1 spacecraft snapped what would become one of the most iconic images ever taken: a view of Earth from 3.7 billion miles (6 billion kilometers) away.

Perhaps the most famous of these photos is the "pale blue dot" image taken by Voyager 1 in 1990. That image shows Earth as a tiny fleck on a beam of sunlight from more than 4 billion miles away.

"They were able to see a blue speck," said Suzanne Dodd, Voyager's project manager at NASA's Jet Propulsion Laboratory in Pasadena, Calif. "And this image represents the Voyager radio signal as ...

If you’ve texted on your Android phone, you may have noticed that some contacts have a small blue dot or a chat bubble on the bottom right of their profile picture. RCS messaging also likely ...