Introduction to the planets Mercury and Venus, the two planets in our solar system closest to the sun.

Learn about telescopes and observatories: the different types and how they work.

Dwarf planets are smaller than planets and can be found throughout the solar system. So far, five dwarf planets have been officially recognized. Scientists think there may be hundreds more dwarf planets in the solar system.

The fifth planet from the sun, Jupiter is the largest planet in the solar system. Jupiter is a giant planet made up of swirling gases and powerful winds. Learn these facts and more.

The planet closest to the Sun, Mercury is the smallest planet in the solar system. Nicknamed the "Swift Planet," it orbits the Sun faster than any other planet. Mercury is known for its extreme heat and steep cliffs.

The sixth planet from the sun, Saturn is known for its rings. These rings can be seen from Earth using a telescope. Saturn also has dozens of moons, including the only moon in the solar system known to have an atmosphere. Learn these facts and more.