As of 2015, scientists define dwarf planets as bodies that are similar to planets in that they orbit a star, are large enough to form a round shape and are not moons. However, dwarf planets do not have sufficient gravity... More » is a website that offers online learning resources for teachers and educational games for kids. Owned by Planet Interactive, Inc., the website is available to members for a yearly fee. More » Technology Internet & Networking

The names of the inner, or terrestrial, planets are Mercury, Venus, Earth and Mars. The outer planets are Jupiter, Saturn, Uranus and Neptune. Pluto was once designated a planet but has now been demoted to a dwarf planet... More » Science Astronomy Planets

Gravity is the force that keeps all of the planets, dwarf planets, moons, asteroids and comets orbiting the Sun. The force of gravity is inversely proportional to the distance of any two objects. This means that objects ... More »

According to NASA, none of the planets in the solar system are known to have exactly four moons. It is noted that Jupiter has four large moons, known as the Galilean Satellites, but the gas giant might have up to 46 addi... More »

Many other planets have moons. There are 166 natural satellites in the solar system orbiting six different planets, including Earth. Jupiter has 63 orbiting moons, followed by Saturn's 60. Uranus has 27 moons, Neptune ha... More » Science Astronomy Planets

The number of moons is constantly changing for some planets as they are discovered, but at the last official count there are 166 moons, with more than 20 waiting to be recognized as moons. This count is only of the moons... More » Science Astronomy Planets