Children's Guide to Our Solar System
The solar system consists of the sun and everything that orbits around the sun. The sun is the central piece of the system, with all of the planets, moons, asteroids, comets, and other space objects orbiting around it. The way the solar system works makes life on Earth possible, as we need gravity to hold us in place. Our proximity to the sun also makes it possible for plants to grow, creating food sources for insects, reptiles, humans, and other animals. Learning about the solar system is one of the most important activities in science.
- The sun contains more than 99.8 percent of the total mass of the entire solar system. (PDF)
- The sun is a very large star that is close to the earth.
- The sun is 149,597,900 km from Earth. It has a radius of 695,508 km.
- The temperature of the sun’s surface is 5,700 degrees Celsius. This means that its temperature is more than 10,000 degrees Fahrenheit.
- Without the sun, life on Earth would not be possible. The sun helps plants grow, giving animals and humans the food they need.
- The sun is made mostly of hydrogen and helium. It also contains oxygen, iron, nickel, magnesium, sulfur, neon, chromium, calcium, and other metals.
- The sun holds all of the planets in their rightful places. This is because the sun has a very strong gravitational pull.
- The sun has three major parts: the solar core, a convective zone, and a radiative zone. It takes thousands of years for light particles to leave the solar core and reach the sun’s surface.
- Mercury is the closest planet to the sun.
- Mercury does not have any known moons.
- Mariner 10 was the first spacecraft to ever get close to Mercury. In 2008, the Messenger flew within 124 miles of Mercury.
- Mercury rotates every 58.647 days. Its orbital period is 87.97 days.
- Mercury is 57 million km from the sun.
- The glare from the sun makes it difficult to study Mercury’s features.
- Mercury contains an iron core.
- This planet is covered with craters that are similar to the craters of the moon.
- The gases floating above mercury are very thin, so scientists say that Mercury has an exosphere instead of using the term atmosphere.
- Mercury’s exosphere contains helium, hydrogen, potassium, sodium, oxygen, and calcium.
- Venus is 107 million km from the sun.
- It takes Venus 224.701 days to orbit around the sun.
- It takes 243.16 days for Venus to make a complete rotation.
- Venus has no moons.
- Venus has a varied landscape, with valleys, mountains and volcanoes making up much of the planet.
- Venus has a metal core, an outer crust of solid rock, and a mantle that is made of liquid rock.
- Venus is too hot to support life.
- The average temperature on Venus is 850 degrees Fahrenheit.
- It takes Earth 365.3 days to orbit around the sun. This is why one year is equal to 365 days.
- Earth is 150 million km from the sun.
- It takes only 23 hours and 56 minutes for Earth to make a complete rotation.
- Earth has an average temperature of 45 degrees Fahrenheit.
- Earth has one moon, which is 384,400 miles from the planet.
- This planet’s atmosphere is made up for argon, nitrogen, and oxygen.
- Earth is composed mostly of magnesium, oxygen, iron, sulfur, magnesium, nickel, aluminum, and calcium. It also contains other elements.
- The atmosphere of Mars is more similar to Earth’s than any of the other planets.
- Scientists believe that Mars once had lakes, streams, rivers, and other bodies of water.
- Mars has two moons, Phobos and Deimos.
- Mars is 229 million km from the sun.
- It takes Mars 686.98 days to orbit around the sun.
- Mars makes one complete rotation in just 24 hours and 37 minutes.
- The atmosphere of Mars is composed of argon, nitrogen, and carbon dioxide.
- Mars has a core made of iron and sulfur.