Space Facts for Kids
Out-of-this-world facts about the universe
Even though Pluto is about 40 times farther from the Sun than Earth, it has mountains that reach nearly 11,000 feet (3,400 meters) high — about the height of the Rocky Mountains. These mountains are made of solid water ice!
Brown dwarfs are sometimes called 'failed stars' because they are bigger than planets but not quite massive enough to ignite nuclear fusion in their cores like a real star. They glow faintly with heat leftover from their formation.
Mars has the largest dust storms in the solar system. These storms can grow to cover the entire planet and last for months. In 2018, a global dust storm lasted so long that it blocked enough sunlight to drain the batteries of NASA's Opportunity rover, ending the mission.
At the center of our Milky Way galaxy sits a supermassive black hole called Sagittarius A*, which is about 4 million times the mass of our Sun. In 2022, scientists captured the first direct image of it using a network of telescopes around the world.
Astronauts on the International Space Station must exercise for about two hours every day to keep their muscles and bones from weakening in microgravity. They use special exercise equipment that is bolted down so it doesn't float away.
Far beyond Pluto lies the Oort Cloud — a vast, spherical shell of icy objects that surrounds the entire solar system. It extends about 100,000 times the Earth-Sun distance and is thought to be the source of long-period comets.
Uranus has its own set of rings, but unlike Saturn's bright icy rings, Uranus's rings are very dark — almost as dark as coal. They were discovered in 1977, by accident, when Uranus passed in front of a star and the rings were seen blocking its light.
The temperature at the Sun's core reaches about 27 million degrees Fahrenheit (15 million degrees Celsius). This extreme heat is created by nuclear fusion, where hydrogen atoms are fused together to create helium, releasing enormous amounts of energy.
The cosmic microwave background (CMB) is the faint glow of radiation leftover from the Big Bang, still detectable throughout the universe. It was discovered accidentally in 1965 when two scientists noticed a mysterious 'noise' in their radio antenna that turned out to be the echo of creation.
Neptune's largest moon, Triton, is the only large moon in the solar system that orbits its planet in the opposite direction of the planet's rotation. This backward orbit means Triton is slowly spiraling inward and will eventually break apart.