NASA's Space Launch System is a heavy-lift rocket designed to carry astronauts to an asteroid and Mars.
Stars are giant, luminous spheres of plasma. Galaxies consist of stars, stellar remnants, dust, gas, and dark matter, bound together by gravity. Learn more about stars and galaxies.
A black hole is a location in space that possesses so much gravity, nothing can escape its pull, even light.
At SpaceKids on SPACE.com, you'll find big questions and answers about everything from the moon to Mars to our Milky Way.
Each day we highlight a spectacular picture from space. See space exploration photos, astronaut pictures and more in our Image of the Day galleries.