Mankind tried to deny that even the Earth was round until an explorer went out on a limb to sail around the world and prove the Earth was, is and will always be as round as it can be. Even so and although Columbus sailed all the way around the Earth by sea, no one could see why all the plants were round and it was once the greatest universal mystery. It wasn’t until the passing of time and a few scientific minds that we finally see and figured it out why planets are round.
ROUND PLANETS EXPLAINED: A SCIENTIFIC VIEW
Derek Sears, professor of cosmochemistry at the University of Arkansas and editor of the journal Meteoritics and Planetary Science, explains that planets are round due to their gravitational field acting as through it originates from the center of the body and pulls everything toward it.
Sears said, “With its large body and internal healing from radioactive elements, a planet behaves like a fluid, and over long periods of time succumbs to the gravitational pull from its center of gravity. The only way to get all the mass as close to planet’s center of gravity as possible is to form a sphere. The technical name for this process is isostatic adjustment. With much smaller bodies, such as the 20-kilometer asteroids we have seen in recent spacecraft images, the gravitational pull is too weak to overcome the asteroid’s mechanical strength. As a result, these bodies do not form spheres. Rather they maintain irregular, fragmentary shapes.”
WHY THE PLANETS ARE ROUND: MORE SIMPLY EXPLAINED:
More simply stated, the answer revolves around the law of gravity. As gravity is pulling all parts of the Earth toward the center, it helps that the Earth is round due to all points on the suface of a sphere are the same distance from the center, so on the surface of a sphere there are no points that are winning over the others ability to reach the Earth’s surface faster. If the Earth wasn’t round but cubed, the corners would be sticking out and gravity would pull on the corners to flatten them out. Then, the corners would be no further away from the center than the sides.
That’s why mountains which move up a few miles higher than the surrounding surface of Earth are being pulled constantly by gravity and this keeps them from getting too high in the sky. They say that parts of the Himalayas are still growing due to the tremendous forces acting to push them up. Then again, other parts of the Himalayas are collapsing under their own weight. Scientists say this is due to the Earth’s gravity which is pulling them down. Even as solid rock, a mountain has little strength when compared to the force or power of the law of gravity.
WHY PLANETS ARE NOT PERFECTLY ROUND:
It’s interesting to note the truth of the matter, which is the fact that the Earth is not exactly as round as it seems. It’s close, but because the Earth rotates around an axis that goes through the north and south poles, it isn’t perfectly round.
We can feel this effect on any child’s play ground and on any, “merry-go-round.” It’s the force we feel when we step to the outer edges of the spinning ride, and we tend to get thrown off our feet In the same way that the Earth reacts in the part of the world where the equator is farthest away from the Earth’s center axis. This force tends to resist and counteract gravity and since this counteracting force is stronger at the equator than at the poles, the Earth is not a perfect sphere or perfectly round at all.
Gravity pulls uniformity in all directions, and the more matter a planet attracts, the stronger the gravity will pull towards its center. A sphere is the natural outcome and all deviations from roundness must withstand the non-gravitational forces to survive the force of gravity pulling downward, but it’s still a bit more complicated due to newton’s laws of motion.
Newton burst our perfectly round bubble when his laws of motion stated that a moving body tends to keep moving and matter at a planet’s equator can be rotating with enough speed to create an outward bulge, and the fact is that Earth does have such a bulge. That’s why planets aren’t perfectly round. Their bulges and rough surfaces depend on mass, size and rotation speed.
TO CONCLUDE:
The source of this and more information on the planets can be found at these sites:
http://www.livescience.com/mysteries/070131_planets_round.html
http://www.scienceline.ucsb.edu/search/DB/show_question.php?key=878939133
