All about planet Earth
Our blue home!
Planet Earth is the only place in the universe where life is known to exist. It is the third planet from the Sun and is home to millions of species, including us humans.
Reason for Seasons
About 70% of the Earth's surface is covered with oceans; the remaining 30% is land. Planet Earth has a tilted axis. The tilted axis is responsible for the northern and southern polar ice caps. It is also what causes the year-round seasonal changes. Mars also has a tilted axis and goes through seasonal changes, which is why scientists believe there may have been life on Mars at one point, or even still today!
Our planet's atmosphere is made up of mostly Nitrogen. Only about 21% of our atmosphere is Oxygen. Even though our planet has water, which is necessary to sustain life, we would have not existed if our atmosphere contained other gases, such as helium and methane like Neptune and Uranus.
Layers of Protection
The atmosphere also protects us from space. Hundreds of asteroids and meteors collide with our planet daily, most of which burn up in the atmosphere and never reach land. Harmful solar radiation is also filtered out by the many layers of our planet's protective shield.
Orbit & Our Lunar Neighbor
It takes the Earth 23 hours and 56 minutes to turn on its axis, so one day on our planet is not exactly 24 hours, but very close to it. A complete orbit around the Sun is about 365 days.
Our planet has one natural satellite, the Moon, which is the only other place in the universe which has been explored by humans. Did you know the Moon's gravitational pull is what causes our seas to have tides? You can learn all about the Moon and its effects on planet Earth here
Return to the kids Solar System page!