Our planet is an incredible, complex system filled with mysteries and surprises. While science is our window into understanding Earth, there are specific facts that are lesser-known or often left out of mainstream discussion. Below are ten shocking facts about Earth that may leave you questioning what you thought you knew.
1. The Earth Isn’t Exactly Round
Contrary to what many believe, Earth isn’t a perfect sphere. It’s an oblate spheroid, slightly flattened at the poles and bulging at the equator. This bulge is caused by Earth’s rotation, which pushes mass outward at the equator. This means you are slightly farther from the Earth’s center at the equator than the poles.
2. The Earth’s Magnetic Field Flips
The Earth’s magnetic field doesn’t stay constant forever. Over millions of years, the North and South magnetic poles have swapped places many times. This process, known as geomagnetic reversal, is unpredictable and can disrupt electronic systems and navigation. Scientists believe we are overdue for the next magnetic field flip, but no one knows precisely when.
3. Earth’s Atmosphere Extends Far Beyond the Moon
Most people assume Earth’s atmosphere stops a short distance above us. Still, recent studies have shown that Earth’s atmosphere, known as the “geocorona,” actually extends about 391,000 miles into space—well beyond the moon’s orbit. This fact means that, technically, the moon orbits within the Earth’s atmosphere.
4. Earth Has More Than One Moon
While the familiar moon is the most prominent natural satellite, other “mini-moons” or quasi-satellites are occasionally captured by Earth’s gravity. These asteroids, which orbit the Earth temporarily, are not as large or stable as the primary moon but still count as temporary moons within Earth’s gravitational hold.
5. The Inner Core is Surprisingly Hotter Than We Thought
Earth’s core is far hotter than initially imagined. Recent studies suggest that the temperature at the inner core may reach up to 10,800°F (6,000°C), which is comparable to the sun’s surface temperature. This intense heat is believed to be generated from radioactive decay and residual heat from Earth’s formation.
6. Earth is Getting Lighter
Contrary to the belief that Earth’s mass remains constant, the planet is gradually losing weight. This is partly due to the escape of gases like hydrogen into space. At the same time, dust and meteoroids continue to fall onto Earth, but the net effect is that our planet’s total mass is slowly decreasing.
7. Days Are Getting Longer
Billions of years ago, a day on Earth lasted only about six hours. Over time, Earth’s rotation has slowed down due to the gravitational pull of the moon, which causes tidal friction. Today, an Earth day is roughly 24 hours, but it continues to lengthen by about 1.7 milliseconds per century. Our descendants will experience more extended days than ours in millions of years.
8. Most of Earth’s Freshwater is Frozen
Although our planet is often called the “blue planet,” only about 2.5% of the Earth’s water is freshwater. Out of this small percentage, nearly 70% is locked away in glaciers and ice caps. The remaining freshwater is found underground, in lakes, rivers, and the atmosphere. This means that the water readily available for human consumption is a small fraction of Earth’s water supply.
9. Earth Once Had a Twin
According to the Giant Impact Hypothesis, about 4.5 billion years ago, Earth may have had a “twin” named Theia, which collided with Earth in a cataclysmic event. The aftermath of this collision is believed to have formed the moon, making Theia a significant influence on Earth’s current state. Scientists have found remnants of Theia’s material in the moon’s composition, supporting this hypothesis.
10. The Oceans Are Still a Mystery
It’s astonishing, but over 80% of the world’s oceans remain unexplored and unmapped. Despite significant technological advances, we still know more about the surface of Mars than we do about our oceans. What mysteries and unknown species lurk beneath the vast, dark depths? That’s a question we’re only beginning to answer.