Facts About Meteors and Meteorites

A meteorite is a large particle from outer space that lands on Earth. They range in size from a grain of sand on up. Around 30 thousand meteorites have been recovered in recorded history; about 600 of them are made ..

Cosmic Rays: Features and Sources

Cosmic rays are invisible, high-energy particles that constantly bombard Earth from all directions. Most cosmic rays are protons moving at extremely high speeds, but they can be atomic nuclei of any known element. They enter Earth’s atmosphere at velocities of ..

Facts About Comets

Comets are basically “snowy dirtballs” or “dirty snowballs”—collections of rocky material, dust, and frozen water, methane, and ammonia that move through the solar system in long, highly elliptical orbits around the Sun. When they are far away from the Sun, ..

Asteroids and Asteroid Belt

Asteroids are relatively small, primarily rocky or metallic chunks of matter that orbit the Sun. They are like planets, but much smaller; the largest asteroid, Ceres, is only about 930 kilometers across, and only ten asteroids larger than 250 kilometers across ..

Kuiper Belt and Kuiper Belt Objects

Kuiper Belt or the Kuiper-Edgeworth Belt is a doughnut-shaped region that extends between about three to eight billion miles (5 to 12 billion kilometers) out from the Sun (its inner edge is about at the orbit of Neptune, while its ..

Facts About Neptune

Neptune is the eighth major planet in our solar system, 17 times more massive than Earth and about four times its diameter. The most remote of the four gas giant planets in our solar system, Neptune takes 165 Earth years ..

Facts about Uranus

Uranus is the seventh major planet in our solar system, and the third of four gas giant planets. It is 51,200 kilometers in diameter, just under four times the diameter of Earth. Like the other gas giant planets, Uranus consists ..

Facts About Saturn, Ring System and Moons

Saturn is similar to Jupiter, although about one-third the mass. A day on Saturn is only 10 hours and 39 minutes long; it spins so fast that its diameter at the equator is 10 percent larger than its diameter from ..