Earth Facts
Our planet, Earth, is the third planet from the Sun. As you might imagine, we have a lot of Earth facts at our disposal.
Earth Facts
Earth is a terrestrial planet. Similar to Mars, Venus and Mercury, we have a hard, rock crust. Planets such as Saturn and Jupiter do not have such crusts. What makes Earth different from all of these planets is it is the only planet to definitely support life in the form of plants, animals and people. Lucky us!
Compared to the planets around us, the Earth is most similar to Mars. While Mars appears to be a dead planet, at one time it had abundant water similar to the Earth. It also has an axis rotation similar to our Earth, which means Mars experiences seasons very similar to ours. Unfortunately, there is no one on Mars to actually celebrate winter, spring, summer and fall.
The Earth is formed much like an onion. If one could peel away the layers, it would occur something like this. The outer layer is the crust, which we call land, and is five to 25 miles thick. Beneath the crust is the mantle, the boundary between the two being known as the Moho discontinuity. The mantle is approximately 1,800 miles deep and is believed to consist of rock. Near the inner core of the mantle called the asthenosphere where heat and pressure temperatures are sufficient to start melting the mantle. The final layer of the earth is the core and there are two sections.
The outer core is molten lava and estimated to be 1,300 miles deep. This section of the core is believed to be the area generating the magnetic field of the Earth. Without the field, solar radiation would literally fry our planet and Earth would look similar to Mars.
The inner core is believed to be solid and roughly 800 miles in thickness. It is believed to consist primarily of iron and nickel. The inner core is under incredible pressures and blindingly hot. It may be as hot as 9,000 degrees Fahrenheit, but does not melt because of the pressure. Since no scientist has physically examined the core, these “facts” may not be accurate.
Earth Facts:
- The Earth is about 4.5 billion years old.
- The Moon formed soon after the Earth.
- The astrological name for Earth is “Terra.”
- The Earth is 93 million miles from the Sun on average.
- The Earth has tectonic plates, which allow the crust to recycle itself.
- The tectonic plates appear to exist because of massive heat and energy radiating out from the inner levels of the Earth.
- The Earth orbits the Sun once every 365.25 days.
- The orbit of the Earth is not a circle, which means it is closest to the Sun each January and farthest from it every July. There is about a three million mile difference.
- Summer and winter are caused by the tilt of the Earth.
- The Earth tilts at roughly 66 degrees.
- When the North Pole is titled towards the Sun, it is summer in the Northern Hemisphere and winter in the Southern Hemisphere.
- The Earth has the only known liquid water in solar system although other planets and moons may have frozen or underground sources.
- There is no universally accepted theory as to how the Earth came to be.
- There is no universally accepted theory as to how our Moon came to be.
- 70 percent of the Earth is covered by water.
- 30 percent is covered by land.
Obviously, this is a small sampling of Earth facts. Volumes upon volumes of books have been written on the subject, but these Earth facts should give you a general impression of our planet.
