1. The Solar System What is a solar system and what does it entail?

2. What is a Solar System? A solar system is the region of space that falls within gravitational influence of a star, or more specifically for us, the Sun. Other than the Sun, the most significant objects in a solar system are the planets, a group of assorted rocky, gaseous, and icy worlds that orbit the Sun, followed by moons that orbit these planets, and other rogue objects.

3. History of the Solar System The solar system is thought to have begun forming about 4.6 billion years ago from a gigantic cloud of gas and dust, called the solar nebula. The cloud contained several times the mass of the present-day Sun, and over a million years ago, collapsed into a spinning disk, whose hot central region became the Sun, while planets and other structures formed from the remaining material.

4. Classifying the Solar System There are nine recognized planets in the solar system. They are categorized as either rocky planets or gas planets. There are also over 140 moons and other countless small bodies such as asteroids and comets in the solar system.

5. The Rocky Planets There are four rocky planets: Mercury, Venus, Earth, and Mars.

6. The Gas Planets Outside the rocky planets, and beyond the ring of asteroids known as the Main Belt, there are four gas planets: Jupiter, Saturn, Uranus, and Neptune.

7. Ice Dwarfs and Beyond Following the gas planets, there is a huge region populated by ice dwarfs, or dwarf planets, which consist of Pluto, the Kuiper Belt object Eris, and the asteroid Ceres. The largest dwarf planet is Eris, and is almost 10 billion miles away from the Sun.