Our Solar System

Written by Stack Jones © 2017. All rights reserved.

The Sun is at the center of our Solar System. The Sun is a dwarf star.

The Sun is matter called plasma. It is mostly made of hydrogen and helium.

The Sun gives us light and energy. We need the Sun for life on Earth.

There are eight planets in our Solar System. Four inner planets and four outer planets.

Mercury is the smallest planet.

It is the closest planet to the Sun. Mercury has no life.

Mercury has no moon.

Venus is the second planet from the Sun. It is the hottest planet in our solar system.

Venus has no water. Venus has no moons.

Earth is the third planet from the Sun.

Earth is our home. We share this planet with many animals.

Animals live on land and in the sea.

Mars is the fourth inner planet.

It has large mountains and active volcanoes. Mars has two moons.

They are named Phobos and Deimos.

Jupiter is a gas giant.

It is the first outer planet. Jupiter has 67 moons.

Io, and Europa are two of Jupiter’s moons.

Saturn is the second largest planet in our Solar System. Saturn has beautiful rings, and many moons.

Titan is Saturn’s biggest moon. Titan is larger than Mercury.

Uranus is an ice giant.

It has rings, like Saturn and 27 moons. The moons of Uranus are made of rock and ice.

Its largest moon is Titania.

Neptune is the farthest planet from the Sun.

It is an icy gas giant. Triton is Neptune’s largest moon.

Triton orbits in the opposite direction of Neptune.

Moons are called satellites.

Satellites orbit around planets. Not all planets have moons.

Earth has one moon. It is called Luna.

There are five dwarf planets.

Pluto, Ceres, Haumea, Makemake and Eris.

Asteroids are too small to be called planets.

Despite their size, asteroids can be dangerous. Many have hit Earth in the past. More will hit Earth in the future.

Beyond Neptune is a space filled with icy bodies. This place is called the Kuiper Belt.

There are trillions of space objects in the Kuiper Belt. Pluto orbits within the Kuiper Belt.

The Oort Cloud is farther away than the Kuiper Belt. It exists in the outermost reaches of our Solar System. Oort Cloud objects are called Trans-Neptunian objects.

Planetoid Sedna is located in the inner Oort Cloud. Planetoid is another name for an asteroid.

Comets are large masses of rock and ice. Gravity from the Sun pulls comets toward it.

Comets melt as they get close to the Sun. The melted ice becomes a gaseous tail.

Comets originate in the Oort Cloud.

Comets are small solar bodies that orbit the Sun. When a comet gets close to the Sun it has a visible coma and tail. The coma is a visible halo of evaporated gas. The dust tail is the easiest part to see. Asteroids are similar to comets but they do not have a visible coma. Planetoids are another name for asteroids. Meteoroids are small particles of debris in the Solar System. A meteoroid is a space body that burns up as it passes through Earth’s atmosphere. Meteorites are meteoroids that don’t burn up in the atmosphere. They collide with Earth’s surface.