Earth: The Only Planet with Life
- Nguyen Khoa
- Jun 14
- 2 min read
What makes Earth the only known world with life?
Introduction
Home is planet Earth—and until this point, the sole planet with life that we know of. With liquid water, breathability, and a magnetic shield to keep us safe, Earth is a special world in our solar system. Everything we know about space starts with what we know about our own world.
What is it?
Earth is a planet with vast oceans, arable land, and an atmosphere that supports all manner of life. It is the sole planet known to have liquid on its surface and the only one that's been demonstrated to have life.
What's In the Name?
In contrast to the other planets, Earth's name is not based on a Greek or Roman god. Instead, its name comes from Old English and German words for "ground.
Size and Distance from the Sun
Earth is the largest among the four terrestrial planets and measures approximately 12,760 km in diameter. It is located 150 million kilometers from the Sun—exactly 1 Astronomical Unit (AU). The Sunlight takes a good 8 minutes to reach Earth.
Orbit, Rotation and Seasons
Earth spins on its axis in 23.9 hours, which gives us day and night. Earth revolves around the Sun in about 365.25 days. To keep our calendar fixed, we add an extra day (leap day) after every four years. Earth's tilt of 23.4° gives us seasons: when one half of the Earth is tilted towards the Sun, it is summer, and the other experiences winter.
Earth's Moon
Earth has a single natural satellite, the Moon. It is roughly 384,400 km distant and is the fifth-largest of the solar system's moons. The Moon helps stabilize the tilt of Earth, which our climate requires. It is believed that it was formed following a giant crash in the early history of Earth.
Rings
Earth lacks rings such as those of some gas giants.
How Was Earth Formed
The Earth was formed approximately 4.5 billion years ago from the residual dust and gas of the Sun's formation. Gravity pulled this material together into a collecting planet with layers.
Explore More
Summary
The planet Earth is the only planet known to be able to support life.
It has one moon and no rings.
It orbits the Sun every 365.25 days and rotates every 23.9 hours.
Earth is made up of four layers: inner core, outer core, mantle, crust.
Its name comes from old words for "ground."
Comments