The Solar System Fourth Grade Science Where are

The Solar System Fourth Grade Science

Where are We? Our Solar System is in the Milky Way Galaxy. We have one star (the Sun), 8 planets, asteroids, comets, meteoroids, moons, rings, and dust in our solar system.

The Sun • We have one star in our solar system. • The difference between a star and a planet is that a star makes its own light. • The Sun is at the center of the Solar System. • The planets orbit the Sun because its gravity is so strong. • The Sun is a medium sized star.

The Inner Planets • They are small, rocky planets that are closer to the sun. • Mercury, Venus, Earth, and Mars are the inner “terrestrial” planets. (terrestrial meaning rocky) • These planets have a metallic core and a rocky crust.

The Inner Planets • Mercury is the closest to the Sun. It is very hot during the day, but freezing cold at night. Mercury is the smallest planet. • Venus is the second planet from the Sun. It is hot and has a lot of craters and active volcanoes. • Earth is the third planet from the Sun. It is not too hot or cold and has liquid water and living creatures. • Mars is the fourth planet from the Sun. Its rocky surface has mountains, canyons, volcanos, and polar ice caps.

• The four outer “gas The Outer Planets giant” planets are • These planets don’t Jupiter, Saturn, have a solid surface Uranus, and Neptune. and are made up of • They are large, gas, liquid, and gaseous planets that sometimes ice. are far from the Sun. • They all have rings, some are just more visible.

The Outer Planets • Jupiter is the fifth planet from the Sun. It has more than 60 moons and a red spot. It is the largest planet. • Uranus is the 7 th planet from the Sun. It lies on its side and has a complicated ring system. • Saturn is the sixth planet. It has 6 rings and around 50 moons. • Neptune is the farthest planet from the Sun. It is extremely far from the Sun so it is very cold. It has 13 moons and 5 rings.

Asteroids, Comets, Meteoroids, and Dwarf Planets • Comets are large pieces of rock or ice that orbit the Sun. They are found in either the Oort Cloud or the Kuiper Belt. • Dwarf Planets are small, spherical objects that circle a star like a planet, but are too small to be considered planets. • Asteroids are large pieces of rock or metal that sit in the asteroid belt and orbit the Sun. • Meteoroids are pieces of asteroid that are thrown off course. When they enter Earth’s atmosphere they’re called meteors.