Earth is a planet. That gleaming blue marble that has enthralled humans since they first set foot on its surface. Why shouldn’t it enthrall us? It is not only our home and the root of life as we know it, but it is also the only world we know of where life thrives.
And we’ve learned a lot about Earth over the last few decades, which has only added to our fascination with it.
But, realistically, how much does the average person know about the Earth? You’ve spent your whole life on Planet Earth, but how much do you really know about the ground under your feet? You already have a lot of fascinating information rattling around in your head, but here are ten more that you may or may not be aware of.
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1. Plate Tectonics Keep the Planet Comfortable
Plate tectonics are found only on Earth, the only planet in the Solar System. Tectonic plates are parts of the Earth’s outer crust that have been broken up.
These are floating on top of the Earth’s magma interior and can collide with one another. When two plates clash, one can subduct (go underneath the other), allowing fresh crust to develop where they pull apart.
This procedure is critical for a variety of reasons. It not only causes tectonic resurfacing and geological activity (earthquakes, volcanic eruptions, mountain-building, and the forming of oceanic trenches), but it is also important to the carbon cycle. When microscopic plants die in the ocean, they sink to the ocean’s floor.
The carbon-rich remains of this life are taken back into the Earth’s interior and recycled over long periods of time. This removes carbon from the atmosphere, ensuring that we do not experience a runaway greenhouse effect as Venus did. There would be no way to recover this carbon if plate tectonics did not function, and the Earth would become an overheated hellish place.
2. Earth is Almost a Sphere
Many people believe that the Earth is shaped like a sphere. This was the scientific consensus between the 6th century BCE and the present period. Scientists have since discovered that the Earth is simply shaped like a flattened disk, thanks to modern astronomy and space travel (aka. an oblate spheroid).
This form is similar to a sphere, but with flattened poles and bulging equator. This bulge on the Earth is caused by our planet’s rotation.
This implies that the distance between the poles is about 43 kilometers less than the diameter of the Earth as calculated around the equator. Regardless of the fact that Mount Everest is the world’s tallest peak, Mount Chimborazo in Ecuador is the feature that is farthest from the Earth’s core.
3. 70% of the Earth’s Surface is Covered in Water
For the first time, astronauts stared back at Earth with human eyes when they first went into space. The Earth earned the moniker “Blue Planet” as a result of their findings. And it’s no surprise, given that oceans cover 70% of the Earth’s surface. The strong crust above sea level makes up the remaining 30%, which is why it’s called the “continental crust.”
4. The Earth’s Atmosphere Extends to a Distance of 10,000 km:
The Earth’s atmosphere is thickest within the first 50 kilometers or so from the horizon, but it extends out to around 10,000 kilometers into space. The Troposphere, Stratosphere, Mesosphere, Thermosphere, and Exosphere are the five primary layers that make up the atmosphere.
The higher one goes into the atmosphere and the farther one is from the earth, the lower the air pressure and density.
The majority of the Earth’s atmosphere is located near the planet’s surface. In reality, the first 11 kilometers above the planet’s surface contain 75% of the planet’s atmosphere.
The Exosphere, however, is the highest layer, reaching from the exobase (located at the tip of the thermosphere at an altitude of about 700 km above sea level) to about 10,000 km (6,200 mi). The exosphere merges with the void of space, which is devoid of any atmosphere.
The exosphere is mostly made up of hydrogen, helium, and a few heavier molecules including nitrogen, oxygen, and carbon dioxide, all of which have very low densities. Since the atoms and molecules are too far apart, the exosphere no longer acts like a gas, and particles escape into space on a regular basis.
These free-moving particles have ballistic trajectories and can travel through the magnetosphere or through the solar wind.
5. Earth is Mostly Iron, Oxygen and Silicon:
You’d get 32.1 percent iron, 30.1 percent oxygen, 15.1 percent silicon, and 13.9 percent magnesium if you could separate the Earth into piles of stuff. Of course, the majority of this iron is found in the Earth’s core. It would be 88 percent iron if you could really get down and sample the heart. And if you took a sample of the Earth’s crust, you’d find that oxygen makes up 47 percent of it.
6. The Earth’s Molten Iron Core Creates a Magnetic Field:
The Earth is shaped like a large magnet, with poles at the geographic poles at the top and bottom. The magnetic field it generates stretches thousands of kilometers beyond the Earth’s atmosphere, creating the “magnetosphere.”
This magnetic field is thought to be produced by the Earth’s molten outer core, where heat causes convection motions in conducting materials to produce electric currents.
Thank your lucky stars for the magnetosphere. Without it, particles from the Sun’s solar wind will directly strike the Earth, exposing the planet’s atmosphere to dangerous levels of radiation.
The magnetosphere, on the other hand, channels the solar wind around the Earth, shielding us from damage. According to scientists, Mars’ thin atmosphere is due to its poor magnetosphere in comparison to Earth’s, which allowed solar wind to slowly strip it away.
7. Earth Doesn’t Take 24 Hours to Rotate on its Axis
The Earth rotates once entirely on its axis in 23 hours, 56 minutes, and 4 seconds, which astronomers refer to as a Sidereal Day. Now, don’t you think that means a day is 4 minutes shorter than we think it is?
You’d think that this time would add up, day by day, and within a few months, day would be night, and night would be day.
But keep in mind that the Earth revolves around the Sun. Every day, the Sun moves by around 1° in relation to the background stars, which is about the size of the Moon in the sky. So, if you sum up the small motion from the Sun that we see when the Earth orbits it, as well as the rotation on its axis, you get a total of 24 hours.
This is a Solar Day, which is the length of time it takes the Sun to return to the same spot in the sky, as opposed to a Sidereal Day. Knowing the difference between the two is like knowing the difference between how long it takes for the sun to rise and set once and how long it takes for the stars to appear in the same position in the sky.
8. A year on Earth isn’t 365 days:
It really is, for fact, 365. There are 2564 days in a year. It’s this additional. Since there are 2564 days in a year, a leap year is needed every four years. That’s why, every four years – 2004, 2008, 2012, and so on – we add an extra day to February. This rule does not apply if the year is divisible by 100 (1900, 2100, etc.), unless it is divisible by 400. (1600, 2000, etc).
9. Earth has 1 Moon and 2 Co-Orbital Satellites
Earth has one moon, as you are probably conscious (aka. The Moon). This body is well-known, and we’ve written several articles about it, so we won’t go into great depth.
But did you know there are two more asteroids orbiting Earth in a co-orbital orbit? 3753 Cruithne and 2002 AA29 are two asteroids that are part of a wider group of asteroids known as Near-Earth Objects (NEOs).
3753 Cruithne is a 5 km wide asteroid that is often referred to as “Earth’s second moon.” It doesn’t fully orbit the Earth, so it does so in a coordinated orbit with it. It also has an orbit that makes it seem as if it is orbiting the Earth, but it is still orbiting the Sun on its own.
Meanwhile, 2002 AA29 is just 60 meters across and orbits the Earth in a horseshoe pattern that takes it within 95 years of the planet. It will start to circle Earth in a quasi-satellite orbit in around 600 years. It has been proposed by scientists that it might be a successful goal for a space exploration mission.
10. Earth is the Only Planet Known to Have Life
We’ve found water and organic molecules on Mars in the past, as well as the building blocks of life on Saturn’s moon Titan. Amino acids can be seen in nebulae in deep space. Scientists have also speculated about the possibility of life under Jupiter’s moon Europa and Saturn’s moon Titan’s icy crusts. However, Earth is the only location where life has been found.
However, if there is life on other planets, scientists are developing experiments to locate it. For example, NASA recently announced the formation of the Nexus for Exoplanet System Science (NExSS), which will spend the next few years sifting through data returned by the Kepler space telescope (and other yet-to-be-launched missions) for signs of life on extrasolar planets.
Today, giant radio dishes are scanning distant stars for the signature signals of intelligent life reaching out into interstellar space.
Newer space telescopes, such as NASA’s James Webb Telescope, the Transiting Exoplanet Survey Satellite (TESS), and the European Space Agency’s Darwin project, may be able to detect life on other planets.