Scientists love to define Earth as a blue ball because it is round and contains a lot of water. The oceans that are the source of this analogy are actually quite special.
On other planets in the Solar System; the water is either absent or is trapped under the ice that extends for miles. Besides, the roundness of the Earth is a different issue.
From Mercury to Neptune, our neighbors are all gigantic spheres. Even planets beyond the Solar System have very round shapes. To understand why, we must examine the first stage of the formation of a planet.
Planets begin to form dust clouds around new stars. These dust clouds collide and stick together to become larger clumps.
Every object in the universe has a gravitational effect; Even ours. As a planet like Earth grows, the gravitational force becomes more powerful. But this effect is only felt if the object takes on a very large form, such as the Earth or the Moon.
When a new planet is very large; the gravitational effect is strong enough to cause the surface to collapse. Iyor This is like collapsing when you sit on a hollow cardboard box, Mark said Mark Sykes, director and CEO of the Planetary Science Institute in Tucson, Arizona. On a newly formed planet, this event takes place in all directions at once, so that the planet takes a round shape.
But for this to happen, the object must have a diameter of about 965 kilometers or more. The shapes of small, weak gravitational objects, such as meteorites or comets, may be more odd. For example, the image of Saturn’s satellite Prometheus resembles a potato. There is also a comet looking like a toy duck that wanders through the Solar System.
But even the Earth is not a perfect sphere. As our planet revolves around itself, the masses of land and water move from center to space as a result of the force caused by this situation. Although the Earth’s gravitational force is strong enough to hold everything in place during the turn, the equator is somewhat protruding.
However, the Moon also distorts the Earth’s shape. The tidal effect of the moon on Earth causes the oceans to rise. It’s not just the oceans; land also rises slightly in the central parts of the Earth due to tidal effects.
These effects can be different for each planet. The planet scientist Mark Panning of NASA’s Jet Propulsion Laboratory in Pasadena, California said, “Mars rotates twice as fast as Earth, but Mars’s gravity is lower than Earth’s; therefore, the protrusions on the surface are more. ” The dwarf planet Haumea, ahead of Neptune, is spinning so fast; more like an American football than a basketball.
In general, these are very small flaws for a large planet. Nevertheless, when you look at Earth, even Mars, from space, they look like perfect spheres.