เฉลย ใบงานที่ 14.1 เรื่อง Know about Earth

Our home planet Earth is a rocky, terrestrial planet. It has a solid and active surface with mountains, valleys, canyons, plains and so much more. Earth is special because it is an ocean planet. Water covers 70% of Earth's surface.

Explore Earth! Click and drag to rotate the planet. Scroll or pinch to zoom in and out. Credit: NASA Visualization Technology Applications and Development (VTAD)

Our atmosphere is made mostly of nitrogen and has plenty of oxygen for us to breathe. The atmosphere also protects us from incoming meteoroids, most of which break up in our atmosphere before they can strike the surface as meteorites.

Since we live here, you might think we know all there is to know about Earth. Not at all, actually! We have a lot we can learn about our home planet. Right now, there are many satellites orbiting Earth taking pictures and measurements. This is how we can learn more about weather, oceans, soil, climate change, and many other important topics.

Structure and Surface

Earth is a terrestrial planet. It is small and rocky.
Earth's atmosphere is the right thickness to keep the planet warm so living things like us can be there. It’s the only planet in our solar system we know of that supports life. It is mostly nitrogen, and it has plenty of oxygen for us to breathe.

Time on Earth

A day on Earth lasts a little under 24 hours.
One year on Earth lasts 365.25 days. That 0.25 extra means every four years we need to add one day to our calendar. We call it a leap day (in a leap year).

Earth’s Neighbors

Earth has just one Moon. It is the only planet to have just one moon.
Earth has lots of spacecraft watching it. There is still a lot we can learn about our home planet.
Earth is the third planet from the Sun in our solar system. That means Venus and Mars are Earth’s neighboring planets.

Quick History

We have known about our planet since ancient times, of course. But we didn’t know our place in the solar system for a long time.

What does Earth look like?

This Apollo 11 picture taken by an astronaut in 1969 shows the Earth rising over the Moon. Doesn't it look small?

This is a view of Earth looking just at the northern portion.

A NASA camera on the Deep Space Climate Observatory satellite took this picture of the entire sunlit side of Earth from one million miles away.

For more information visit:

NASA Solar System Exploration

Real World: A-Train
Our World: A-Train
Real World: Earth Systems

article last updated September 1, 2021

Overview

Our home planet is the third planet from the Sun, and the only place we know of so far that’s inhabited by living things.

The Latest

While Earth is only the fifth largest planet in the solar system, it is the only world in our solar system with liquid water on the surface. Just slightly larger than nearby Venus, Earth is the biggest of the four planets closest to the Sun, all of which are made of rock and metal.

The name Earth is at least 1,000 years old. All of the planets, except for Earth, were named after Greek and Roman gods and goddesses. However, the name Earth is a Germanic word, which simply means “the ground.”

Go Farther: Explore Our Home Planet In Depth ›

Ten Things to Know About Earth

10 Need-to-Know Things About Our Home Planet

Measuring Up

If the Sun were as tall as a typical front door, Earth would be the size of a nickel.

Third Rock

Earth orbits our Sun, a star. Earth is the third planet from the Sun at a distance of about 93 million miles (150 million km).

As the World Turns

A day on Earth is 24 hours. Earth makes a complete orbit around the sun (a year in Earth time) in about 365 days.

We're On It

Earth is a rocky planet with a solid and dynamic surface of mountains, canyons, plains and more. Most of our planet is covered in water.

Breathe Easy

Earth's atmosphere is 78 percent nitrogen, 21 percent oxygen and 1 percent other ingredients—the perfect balance to breathe and live.

Our Cosmic Companion

Earth has one moon.

Ringless

Earth has no rings.

Orbital Science

Many orbiting spacecraft study the Earth from above as a whole system—observing the atmosphere, ocean, glaciers, and the solid earth.

Home, Sweet Home

Earth is the perfect place for life as we know it.

Protective Shield

Our atmosphere protects us from incoming meteoroids, most of which break up in our atmosphere before they can strike the surface.

Pop Culture

Storytellers explore the nature of our planet and possible alternate realities in many books, movies, and television shows. The iconic film "Planet of the Apes" (and its sequels) takes place in a future in which astronauts "discover" a planet inhabited by highly intelligent apes and primitive humans, only to realize later, much to their dismay, that – spoiler alert! – it was Earth all along.

In the long-running and re-booted television series "Battlestar Galactica" – tired survivors of a war with highly evolved robots called Cylons are on a quest to find Earth, a long-lost colony.

In other stories, Earth has been abandoned or destroyed, such as in the Joss Whedon series "Firefly," or the book and its film adaptation "The Hitchhiker's Guide to the Galaxy." In the animated feature "Titan A.E." – Earth has been destroyed by an alien species, but a well-placed planet builder recreates it and all the species that live on it.

Kid-Friendly Earth

Earth's atmosphere is made mostly of nitrogen and has plenty of oxygen for us to breathe. The atmosphere also protects us from incoming meteoroids, most of which break up before they can hit the surface.

Visit NASA Space Place for more kid-friendly facts.

NASA Space Place: All About Earth ›