We all know Earth is round, but did you know it's not a perfect sphere? Thanks to gravity, Earth's shape is more like a slightly squished ball. The equator bulges out a bit, making the equatorial radius 6378.38 kilometers, while the polar radius is slightly shorter at 6356.89 kilometers.
So, Earth looks more like a football than a tennis ball!
1. The Origin of the Name "Earth"
Unlike the other planets in our solar system, which are named after Greek and Roman gods, Earth's name comes from an Old English word "Erda," which means “ground” or “soil.” Surprisingly, Earth should probably be called the "Water Planet" instead, because 71% of its surface is covered in water. It's the only planet we know of in the entire universe that has liquid water on its surface!
2. Earth's Day Is Not Exactly 24 Hours
We think of a day as being 24 hours, but Earth's actual rotation is slightly shorter. It takes about 23 hours, 56 minutes, and 4 seconds for Earth to complete one full rotation around its axis. This is known as a "sidereal day," which is measured relative to distant stars. The "solar day," the one we usually follow, is the time it takes for the Sun to return to the same position in the sky, and it changes by about 16 minutes each year due to Earth's orbit around the Sun.
3. Earth Is the Only Planet Known to Have Plate Tectonics
Earth's crust is made up of seven major tectonic plates that move slowly over time. These plates shift about 10 centimeters per year, and when they collide, mountains can form. When they pull apart, valleys or canyons might emerge. Plate movements also cause earthquakes and volcanic eruptions, but they play a crucial role in cycling carbon, which is essential for life.
4. Earth Had a "Sister Planet"
Scientists believe Earth once had a "sister" planet named Theia. About 4.5 billion years ago, Theia, roughly the size of Mars, collided with Earth. Most of Theia's material merged with Earth, but a chunk of it was ejected into space, eventually coming together to form the Moon. This theory is supported by the surprising similarity between Earth and Moon's metal isotopes, as well as the Moon's size compared to Earth—quite large for a satellite!
5. The Moon's Orbit is Almost Perfect
We might think the Moon's orbit would be unstable, especially since it's only 1,800 kilometers closer to Earth than it should be. But surprisingly, its orbit is nearly circular and incredibly stable. What's even more fascinating is the perfect coincidence of the Sun's and Moon's apparent sizes. The Sun is 400 times larger than the Moon, but it's also 400 times farther away, which is why the Moon and Sun look nearly the same size from our perspective on Earth.
6. More Than 90% of Earth's Oceans Remain Unexplored
While we've been to the Moon and Mars, we've only explored less than 10% of Earth's vast oceans! We've discovered over 212,000 species of marine life, but scientists estimate that there could be as many as 25 million species yet to be discovered. The ocean's depth and complexity are still full of mysteries waiting to be uncovered.
7. Earth Holds Extreme Temperature Records
Earth has some seriously extreme temperatures. The coldest place on Earth is Antarctica, where a temperature of -89.22°C was recorded at Vostok Station in July 1983. On the flip side, the hottest temperature ever recorded was 57.78°C in Libya, on September 13, 1922. These temperature extremes remind us just how varied and extreme our planet's climate can be.
8. The Tallest Point on Earth Isn't Mount Everest
While Mount Everest holds the title for the highest peak above sea level at 8,849.87 meters, it's not the furthest point from the center of the Earth. That title goes to Mount Chimborazo in Ecuador. Although Chimborazo is only 6,267.91 meters tall, it's located near the equator, where Earth's bulge is greatest, so it's actually 2,414.02 meters farther from the Earth's center than Everest.
Now, Lykkers, how cool is it to learn about these surprising facts about our planet? Earth truly is an amazing place, full of mysteries and surprises waiting to be explored. So next time you look at the sky or stand on solid ground, remember just how unique and fascinating our home really is!
