Eventually these small parts grew from the size of sand into the size of mountains. These mountains of rock and ice are fluffy, like giant dirty snowballs.
So the small mass - and weak gravity - of the whole mountain is unable to overcome the hard shape of the rock and ice lumps to become round.
Read more: Curious Kids: Why do stars twinkle? Fluffy mountains like these got swept together billions of years ago to make the planets we recognise today. But some of them are still minor objects in the Solar system. These bits of leftover planet-building material, called asteroids and comets, have very lumpy shapes. Some are shaped like potatoes and others like eggs. The largest of these minor bodies, such as Ceres and Pluto, have enough gravity to look round like a planet.
They are called dwarf planets. Some, like Haumea, spin very fast, giving them an stretched shape, like this:. Hello, curious kids! Ask an adult to send your question to us. You can:. Please tell us your name, age and which city you live in. You can send an audio recording of your question too, if you want. You have answered 0 of 3 questions correctly and your score is:. Want to add a little wonder to your website?
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Why is Earth round? Is Earth perfectly round? Does Earth's shape ever change? Wonder What's Next? Tomorrow's Wonder of the Day might require a stiff upper lip!
Try It Out Can you believe that people once thought Earth was flat? As soon as you get aROUND to it, check out the following activities with a friend or family member: Put yourself in the shoes of the people who lived hundreds of years ago.
Without the science we know today, what would you have believed about Earth? Stand up, turn around, and take a walk outside. Look around you. Was it really that strange to think that Earth was flat? Or that the Sun revolved around Earth? Isn't it interesting how your perceptions of the world around you could lead to a completely-wrong view of the universe?
In what other ways do you think your perceptions might fool you? You can do anything you want. The new planet doesn't have to look or be like any other planet in existence.
What would you design? Would you stick with the sphere shape? Or would you branch out in a totally new direction? Give it some thought and then draw a picture of what your planet would look like.
Share it with a friend or family member and be prepared to explain why you would design a planet as you did. Have fun and be creative! Earth is really a neat place. We're lucky to call it home. In honor of our home planet, take some time today to check out some Amazing Images of Earth from Space.
Which images are your favorites? If you could fly to outer space, what kind of pictures of Earth would you like to take? Did you get it? Test your knowledge. Wonder Words round shape mass sense cube pole gravity sphere equator force static surface ellipsoid geodesy centrifugal tectonic astronomer interrelated Take the Wonder Word Challenge. Join the Discussion.
Dec 11, Shaan Nov 12, Nov 13, Hi Shaan! It's a safer bet to use the 'accessed' date if you're citing this Wonder.
We update and 'refresh' our Wonders periodically. I love this information. I will give this information a lot of credit. I am going to use this information for my school project. If you're going to use information from this Wonder, don't forget to cite your sources! ChaseUnited1 Nov 11, Nov 11, Saz May 6, May 6, Not just air--a lot of things.
Harlie Apr 17, Apr 18, Thanks for sharing, Harlie. Shaan Nov 7, That's great, Shaan! What was your favorite fact? BillyBobJoe Apr 4, How is the earth spherical if we have mountains? Apr 4, It is flat Apr 4, Thanks for offering your opinion, Wonder Friend! Thanks for sharing your thoughts, ChaseUnited1.
Mar 21, Mar 15, Vivian Mar 14, My classmate told me we live inside earth but I told her then we'd live in the earths core Mason : Mar 13, Wow that was a cool wonder by the way how do you use emojis?
Mar 13, We have a button to click for them in the super-secret Wonderverse. Mar 11, That actually depends on which country and why someone is traveling there, Wonder Friend.
It seems like that might be the case, but it's not. May 14, Hi, jack! The Earth is round! This Wonder will help explain more! Eli Simon May 7, I recommend it because it was quite interesting to learn about! May 9, Thanks, Eli! In , Galileo Galilei observed the moons of Jupiter rotating around it. He described them as small planets orbiting a larger planet—a description and observation that was very difficult for the church to accept, as it challenged a geocentric model where everything was supposed to revolve around the Earth.
This observation also showed that the planets Jupiter, Neptune, and later Venus was observed too are all spherical, and all orbit the sun.
A flat planet ours or any other planet would be such an incredible observation that it would pretty much go against everything we know about how planets form and behave. We know it. The time in New York, at the moment these words are written, is pm.
In Adelaide, Australia, it is am. More than 13 hours ahead. There, the sunset is long gone—so much so, that the sun will soon rise up again at the beginning of a new day. This can only be explained if the world is round, and rotating around its own axis. At a certain point when the sun is shining on one part of the Earth, the opposite side is dark, and vice versa. That allows for time differences and time zones, specifically ones that are larger than 12 hours.
Similarly, you can see the light coming out of a spotlight on a stage in the theater, even though you—the crowd—are sitting in the dark. The force of attraction gravity between two objects depends on their mass and the distance between them.
Simply said, gravity will pull toward the center of mass of the objects. To find the center of mass, you have to examine the object. Consider a sphere. Since a sphere has a consistent shape, no matter where on it you stand, you have exactly the same amount of sphere under you. Imagine an ant walking around on a crystal ball. This will occur no matter where on the surface the object is located.
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