Why Are Planets Round? | Spherical Planets Facts & Information

Home » Why Are All Planets Round » Why Are Planets Round? | Spherical Planets Facts & Information

Maybe your like

Skip to content Why are planets round? Menu Home » Space Questions » Why are planets round?

If you have ever looked at pictures of our planets, or lined them up side by side to inspect them, then you might notice something interesting–all the planets are round. Naturally, you might ask, “why are planets round?” The answer to this question rests in how planets are formed and how gravity works.

When rocks, gas, and dust start to run into each other in space, some pieces may stick together or clump together. As all these bits and pieces of rock, dust, and gas gather, they begin to create their own gravity, which helps hold it all together. These forming planets are very hot, and they are usually molten.

Gravity then begins to work on the hot and molten materials. Gravity pulls equally from all sides. Since the gravity is at the very center of the material, the material is pulled towards the center of the mass equally. Since the material is pulled towards the center equally, the material begins to take a spherical shape.

As the bulky and heavy materials begin to crash towards the center, the molten materials and pressure begin to push outwards. The combination of weight pushing in and pressure pushing out creates balance. The balance is created and maintained through a spherical shape.

After the material cools, it remains in its spherical shape. This is why our planets are round. However, they are not perfect in shape. Since planets spin, there can be bulges in their round shapes. The faster the planet spins, the bigger the bulges. Meaning faster spinning planets might be a little less spherical than other planets, and they could be a little flattened.  Additionally, objects can impact planets, creating craters and bumps on their surfaces.

For comparison, you can look at asteroids. Smaller asteroids are generally not round. In fact, they are jagged, fragmented, and irregular in shape. This is because small asteroids have very weak gravitational pulls, meaning they cannot pull all the material surrounding them towards their center equally. Therefore, unlike planets, these small asteroids are not spherical and round.

Planets are round because gravity causes all the material to gather equally around a gravitational center, but not all planets are perfectly round. They have imperfections in their shapes and on their surfaces, but they generally keep their round, spherical shape.

Space Questions

  • How Long Does it Take to Get to Jupiter?
  • How Far is Mercury from Earth?
  • How Long Does it Take to Get to Pluto?
  • What is the Big Bang Theory?
  • How Many Moons Does Jupiter Have?
  • How Long Does it Take to Get to Ceres?
  • How Far is Mars From the Sun?
  • How Long Does Uranus Take to Go Around the Sun?
  • When Will Betelgeuse Explode?
  • How Big is the Universe?

Buyer’s Guides

  • Best Space T-Shirts for Kids
  • Gskyer vs Orion vs Celestron vs Meade Instruments Telescopes
  • Best Space and Astronomy Books for Adults
  • 10 Best Laptops For Astronomy/Astrophysics
  • Best Data Science Courses
  • Best Space Games for PS4
  • Best Space Toys and Toy Rockets
  • Best Orion Telescopes
  • Best Space-Themed Board Games
  • Best Online Photography Courses

Latest Buyer’s Guides

  • How to choose your telescope magnification?
  • Best Space (Astronomy) Hoodies for Kids
  • Best Space T-Shirts for Kids
  • Best High Power Binoculars for Experts
  • Best Travel Telescopes
  • Choosing Your Astronomy Equipment
  • Best Space T-Shirts Adults
  • Best Astronomy Gifts under $100
  • Monocular vs. Binoculars- Which One is Best for Stargazing

Tag » Why Are All Planets Round