A Picture of our Solar System

Solar System Facts for Kids

This web page contains Solar System facts for kids and is a great resource for anyone researching our Solar System. We're going to provide you with the latest and most accurate facts about the Solar System from scientific sources. Alongside Solar System facts, you'll get to see some awesome diagrams of our Solar System.

The star facts below will help you understand what our Solar System is, how many planets are in our Solar System, how old the Solar System is, and other useful facts about our Solar System. We hope the below facts about our Solar System are helpful and make researching it fun, while you explore our Solar System.

If any of the below Solar System facts are inaccurate or out of date, please contact us and let us know.


18 Solar System Facts for Kids

  1. The Solar System is a system bound by gravity that contains Earth, the Sun, planets, natural satellites (moons) and other astronomical bodies and objects.
  2. Our Solar System formed about 4.6 billion years out of huge interstellar molecular cloud.
  3. The mass of our entire Solar System is 1.0014 solar masses. One solar mass is equal to the size of our Sun. This means our Sun makes up over 99% of the mass in our Solar System.
  4. The Sun in our solar system is a G2-type main-sequence star and is around 4.6 billion years old.
  5. There are eight planets in our Solar System.
  6. There are four inner planets (terrestrial planets), and they are Mercury, Venus, Earth and Mars.
  7. There are four outer planets (gas giants), and they are Jupiter, Saturn, Uranus and Neptune.
  8. Between 1930 and August 2006 Pluto was the fifth outer planet and brought the total of planets in our Solar System to nine. However, in September 2006, the IAU demoted Pluto to a dwarf planet.
  9. Mercury is the smallest planet in our Solar System and has the least amount of mass of any planet.
  10. Jupiter is the largest planet in our Solar System and has the most mass of any planet.
  11. The last confirmed planet to be discovered was Neptune.
  12. There are 575 known natural satellites (moons) in our Solar System.
  13. There are 796,354 minor planets in our Solar System as of 2019.
  14. The asteroid belt in our Solar System separates the inner and outer planets.
  15. The total mass of the asteroid belt in our Solar System is equal to about 4% of the Earth's moon.
  16. The nearest star to our Solar System is Proxima Centauri at 4.24 light-years away.
  17. Humans have explored every planet in our Solar System with surfaced based telescopes, space based telescopes and space probes.
  18. Humans have only physically visited one astronomical body in our Solar System, and that was the moon.

Additional Resources to Research the Solar System