These 80 space trivia questions are great to play with friends, challenge your family with or play by yourself. See how much ...

The beautifully illustrated — aimed at children and middle-schoolers, but just as fascinating for adults — manages to answer questions you've... Time travel, asteroids, planets and urban legends ...

How far it is from the sun: 886 million miles (1.4 billion kilometers), on average How big it is: 72,400 miles (116,500 km) across, or almost 10 times the size of Earth. How many moons it has: At ...

Ah, Earth. We may not think about our planet on a day-to-day basis, but the world we live in is a pretty interesting place. The third rock from the Sun—and to this day, the only one with known ...

Earth is our home planet, and it's the only place in the universe where we know for certain that life exists. Earth formed over 4.5 billion years ago from a swirling cloud of gas and dust squished ...

Discover the order of planets in the solar system. From Mercury to Neptune, explore our solar system and learn more about our cosmic home. The solar system is our cosmic neighborhood, made up of the ...

Today, April 22, is Earth Day, a time to appreciate our planet and the two-way relationship we have with it. It’s easy to take Earth for granted, since we see it every day. It becomes—it is—part of ...

Dwarf planets are worlds that are too small to be considered full-fledged planets, but too large to fall into smaller categories. In recent years, there's been a lot of hubbub about Pluto losing its ...

CAPE CANAVERAL, Fla. (AP) — Talk about an Earth-shattering discovery. Scientists have spotted seven Earth-size planets around a nearby star, some or all of which could harbor water and possibly life.