Ask someone on Earth for the time and they can give you an exact answer, thanks to our planet's intricate timekeeping system, built with atomic clocks, GPS satellites and high-speed telecommunications ...

You know how it goes: You’re trying to get some shut-eye in your bunk after a long shift of scraping samples of prebiotic material from red rocks in Utopia Planitia, and before you know it, your alarm ...

Intuitively, we know what time is, but try to explain it, and we end up tying our minds in knots. When you purchase through links on our site, we may earn an affiliate commission. Here’s how it works.