Earth is the third planet from the sun and the fifth largest planet in the solar system. It's a terrestrial planet, which means it has a hard surface made up of rocks and metals. Earth is the largest terrestrial planet, ahead of Venus, Mars, and Mercury.
Unlike the other planets, the earth wasn't named after a god. The name Earth came from the Old English word, 'Ertha,' which means 'ground' or 'soil.' Amazingly, even though the earth is basically named after ground or soil, more than 70 percent of the planet is covered in water. Maybe we should have called it Aqua! Most life on Earth lives in the water. Did you know that the most diverse population on Earth can be found in the coral reef systems of the ocean?
The earth has a very strong magnetic field, which helps keep the atmosphere around the planet in place. It takes the earth about 365 days, or a year, to orbit the sun and 24 hours to rotate on its axis, making a day. The earth also has four distinct seasons based on where it is on its revolution around the sun. The earth has one orbiting spatial body that we call the moon. It's rocky, small, and revolves around the earth about every month.
Earth has just the right combination of water, atmosphere, and climate to support life as we know it. There is also a layer in the atmosphere called the ozone layer, which protects the planet from the radiation and heat of the sun.
So what does Earth have that allows for life that the other planets don't have? Well, there's a combination of a few things. First, Earth has a lot of water, and water is essential for life. Animals and plants need water, and Earth has enough for both. Since there's so much water on Earth, it is often called the Blue Planet.
The atmosphere of Earth contains the right mixture of gases, like oxygen, to support life and the temperatures are right to allow life to survive. The other planets in the solar system don't have this mix. They're either too hot or too cold, don't have water or don't have the atmosphere to support any life.
Cool Earth Facts
Let's go over a couple of other cool facts about Earth before we wrap this up:
- The gravity from the moon causes the oceans on Earth to rise and fall, which we call the tides.
- For a long time, people thought that the Earth was the center of the universe. It wasn't until 1543 when a scientist named Copernicus created the sun-centered model.
- The highest point on Earth is Mount Everest and the lowest point is below the ocean floor called Challenger Deep.
Okay, let's take a second to review. Earth is the third planet from the sun and the fifth largest planet. We learned that Earth is a terrestrial planet, which means it has a hard surface made up of rocks and metals. Its surface is more than 70 percent water and is the only planet known to support life, largely thanks to its atmosphere, which contains the right mixture of gases, like oxygen, to support life, and the ozone layer, which protects the planet from the radiation and heat of the sun. Generally speaking, Earth has the right combination of water, atmosphere, and temperature to support an abundance of living species.
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Planet Earth: True or False Activity
This activity will help you assess your knowledge of the astonishing facts about our planet, the Earth.
Determine whether the following statements are true or false. To do this, print or copy this page on a blank paper and underline or circle the answer.
True | False 1. Earth is the only planet known to have an atmosphere containing free oxygen.
True | False 2. The Earth orbits around the Moon in about 365 days or approximately a year.
True | False 3. The Moon is a rounded astronomical body that orbits the Earth, serving as the planet's only natural satellite.
True | False 4. Earth is also known as the Green Planet, owing to its abundant vegetation.
True | False 5. Perhaps the most striking thing about the Earth is the presence of living organisms.
True | False 6. The oxygen layer is a thin part of the Earth's atmosphere that absorbs almost all of the Sun's harmful radiation.
True | False 7. Earth's weak magnetic field keeps the atmosphere intact and protects the planet from things in space, such as rocks and solar radiation.
True | False 8. The Earth's movement around the Sun causes the planet to have four distinct seasons.
- False, because the correct statement is: The Earth orbits around the Sun in about 365 days or approximately a year.
- False, because the correct statement is: Earth is also known as the Blue Planet, owing to its abundant water content.
- False, because the correct statement is: The ozone layer is a thin part of the Earth's atmosphere that absorbs almost all of the Sun's harmful radiation.
- False, because the correct statement is: Earth's strong magnetic field keeps the atmosphere intact and protects the planet from things in space, such as rocks and solar radiation.
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