KOMPAS.com – Earth is a place where humans, animals, and plants can live because it has water and oxygen needed by living things. When talking about the Earth, the discussion about its shape is very interesting.
Planet Earth is one of the secrets of the universe and is still being studied, so many scientists believe that the planet we live in is round like a ball.
But it turns out, the shape of the Earth is not a perfect sphere but rather slightly oval like an egg.
So, why is the shape of the Earth not perfectly round?
Before answering this question, let’s first know the highest peak on Earth.
If measured from the center of the Earth, the highest peak of our planet is Mount Chimborazo in Ecuador, not Mount Everest which is known as the highest mountain in the world.
Reported from Live ScienceSunday (3/4/2022) Mount Chimborazo is superior in this regard because planet Earth is actually a little squeezed at the poles.
If likened to, like a ball pressed by two hands on the top and bottom. Thus, the equator where Ecuador is located is more prominent.
Also read: Mystery of Rare Gas Leaking from Inside the Earth’s Core, Study Reveals Formed After the Big Bang
Instead of a perfectly round ball shape, the shape of the Earth is oblate which means it is shaped like a rather flat ball and oval like an egg.
However, the oval shape is only slightly, which means the Earth still looks perfectly round even though many people don’t realize it.
“In fact, most planets and the Moon are not true spheres. They are usually squeezed in some way or another,” said James Tuttle Keane, a planetary scientist at NASA’s Jet Propulsion Laboratory in Pasadena, California, United States.
What makes the shape of the Earth not perfectly round?
He added that the reason the Earth, other planets and the Moon are not perfectly round is the centrifugal force or external force experienced by a rotating object. A rotating planet, he said, must experience centrifugal force.
Simply put, when you turn in a chair or on your feet you will feel a tug from the center of your body. This may cause a sprained arm or leg.
“Or, if you’re sitting on a merry-go-round, there’s a little extra force acting on you while on the merry-go-round, so you feel like you’re being pulled sideways,” explains Keane, describing why the Earth isn’t perfectly spherical.
Also read: Why Earth and Other Planets Are Spherical, Not Flat?
As the planet and Moon rotate, centrifugal force causes the object to bulge at its equator. The effect can be seen on the two largest planets in the Solar System, Jupiter and Saturn.
If you look at the image of one of these gas giants, you will notice that the two are slightly squeezed while the center is protruding.
Keane explained that the pinched shape of these planets is more visible, because they are the fastest rotating planets in the Solar System. He explained, the faster something rotates, the greater the centrifugal force acting on an object.
An extreme example of the centrifugal force acting on an object is the dwarf planet Haumea. The dwarf planet is in the Kuiper Belt which is a region of icy objects outside the orbit of Neptune.
“Haumea is the size of Pluto, but rotates very fast, one full rotation every four hours, so that its existence is almost shaped like an egg,” Keane said.
Also read: Characteristics of Planet Earth, the Fifth Largest Planet in the Solar System
Early on humans knew the shape of the Earth was round
As reported from the page NASAWednesday (4/10/2017) humans have known that the Earth is round for more than 2,000 years ago.
At that time, the Ancient Greeks measured the shadow during the summer solstice, then calculated the circumference of the Earth.
They use the positions of stars and constellations to estimate distances on Earth.
The Ancient Greeks could even see the spherical shadow of the planet during a lunar eclipse. Until now, humans can still see the shadow of the earth during a lunar eclipse.
Meanwhile, in today’s modern era, scientists use geodesy, which is the science of measuring the shape, gravity, and rotation of the Earth. The geodetic technique provides accurate measurements that show that the Earth is spherical in shape.
Using GPS and other satellites, scientists can measure the size and shape of the Earth. Images from space also show planet Earth as spherical like the Moon.
Also read: Earth’s Rotation in 2021 is Called Slowing, What Happens?
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