Earth might be a mere pale blue dot in the grand scheme of the cosmos, but it remains central to our own existence. While it might not seem as exotic as some of the far-off planets we hear about, there is no denying that Earth is quite unique. And this isn’t just because it’s the only planet we know of that can sustain intelligent life–there are countless other interesting facts about the planet Earth. Here are a few of our favorites.
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Interesting Facts About the Planet Earth
1. Earth is moving faster than you think.
Even though we can’t sense it, our planet is always in motion. Earth travels in its orbit around the Sun at an average velocity of 18.5 miles per second. It makes one complete spin on its axis every 23.9 hours. It is this constant motion that gives us both the seasons, and our night/day cycle.
More reading: Why Do We Have Seasons?
2. Earth is roughly 4.5 billion years old.
However, it would take Earth a little time to reach its current form with four distinct layers of its interior (crust, mantle, outer core, inner core).
3. Earth is the densest planet in the solar system.
Remember those layers we just mentioned? They help contribute to this statistic. However, each part is different, with the core being denser than the crust. On average though, the planet is 5.52 grams dense for each cubic centimeter.
4. The Earth is the only planet in our solar system not named for a mythological figure.
The bulk of our fellow planets like Mercury, Neptune, and Jupiter take their names from mythological figures, namely, Roman gods. However, Earth is derived from the Old English word ertha, meaning “ground” or “land”.
5. The Earth is 70% water.
It’s easy to forget how much of the Earth is water. And the vast majority of this is saltwater in the world’s oceans. In fact, our oceans contain 95.6% of the entire planet’s water supply.
For more, check out: Why Is the Ocean Salty?
6. That water wasn’t always on the Earth’s surface.
There are a few theories on how the oceans came to be. One of the most common ones is that there were massive amounts of water vapor trapped beneath the Earth’s surface after its creation. Volcanic activity helped release this into the atmosphere, and it then fell as liquid water.
7. The Earth’s magnetic field keeps changing.
Since the 19th century, the Earth’s magnetic field has weakened by around 10%. This isn’t the most dramatic change we’ve ever seen, though. Roughly every few million years, the North and South Pole actually switch places, with the process taking up from 100 to 3,000 years.
8. The atmosphere technically reaches 10,000 km into space.
While it’s thickest in those first 50 km, there are actually 5 separate layers of Earth’s atmosphere: troposphere, stratosphere, mesosphere, thermosphere, and exosphere. Air pressure and density decrease the further you go up.
Quiz yourself: Click the Layers of the Earth & Atmosphere
9. There’s a reason you don’t see a lot of craters on Earth.
If you look at Mars or the Moon, craters regularly dot the surface. However, Earth’s regular cycle of geological activity ends up erasing a lot of these remnants of meteorites and other impacts on the planet.
10. Earth’s orbit is one of the most circular in the solar system, and that’s important.
Compared to other planets the orbit of the Earth stays close to a complete circle. This is essential because it ensures the planet gets a similar amount of sunlight year-round, even if it’s not all on the same parts of it.
11. You can’t see the Great Wall of China from space (not easily, anyway).
It’s a common misconception that can actually see the legendary structure from space, but in reality, this is only possible with support and on certain days. You have a much better chance of seeing major cities, as well as structures like dams and reservoirs.
12. Earth isn’t a sphere (technically).
While you may picture the Earth as a perfect globe, in reality, it’s rotation makes it an oblate spheroid. Basically, it’s squashed at the poles and extended at the equator.
Did you like these facts about Earth? If so, you might enjoy these other articles from the Sporcle Blog.
- How Fast Does Earth Spin?
- Why Is Our Galaxy Called the Milky Way?
- Interesting Facts About the Planet Venus