The Earth is the third planet from the sun, and arguably the most special one. It is named after an Old English word and happens to be the only planet in our solar system that has not been named after a Greek or Roman god or goddess. But the name is not the only thing about the blue planet (which is mostly water) that is special.
There are many interesting things that can be learned about our planet, and in addition to the information about its chemical composition and the extreme heat of its core, the Earth is also an unusual place because it is the only planet in the solar system which is known to sustain life. And not just life, but intelligent life, as it’s teeming with billions of animal and plant species, as well as unusual life forms, including the largest living organism in the world, which just so happens to be a type of mushroom.
The Earth may not be the center of the universe and humans no longer believe it to be so, but it is unlike any other planet for good reason. And below are 25 lesser known things about the Earth that give a new appreciation for it.
25 The Earth's Atmosphere Extends 10,000 KM Into Space
The Earth’s atmosphere protects us from heat and radiation from the sun, Space reports. Many people are aware that we have an atmosphere, and that it is the only one in the solar system capable of sustaining life, but fewer will realize just how far it extends.
The atmosphere consists of five main layers, the outermost layer is the exosphere, the thinnest layer where the Earth meets outer space. According to Universe Today, although the atmosphere extends around 10,000 km into space, within the first 11 km above the Earth’s surface is where 75 percent of the Earth’s atmosphere is contained.
24 The Atmosphere We Have Today Is Vastly Different From What Existed During Earth's Infancy
In keeping with the information about the atmosphere, it's important to note the composition of the atmosphere, which according to NASA, is: “78 percent nitrogen, 21 percent oxygen and 1 percent other ingredients.” These other trace amounts include carbon dioxide, helium, hydrogen, methane, krypton, nitrous oxide, xenon, iodine, ammonia, ozone, and carbon monoxide, Universe Today notes.
The publication also notes an interesting difference between the atmosphere we have today, and Earth’s early atmosphere (around 4.4 billion years ago), which was 100 times as dense.
23 The First Photo Of Earth From Space Was Taken In 1946 And Was Particularly Grainy
Many photos have been taken of the Earth from space, all of which are a reminder of the beauty of our planet, and just how small we are in comparison. But the first photograph ever taken of Earth was in 1946, by cameras attached to a V-2 missile, launched from the White Sands Missile Range, Air & Space reports.
The photo was taken from an altitude of 65 miles, and although it was nothing like the blue and green photos we see of the Earth now (this one was grainy and black-and-white), the publication notes that the image did show the planet against the blackness of space, which created great excitement among the scientists at the time.
22 Cosmic Dust Is Always Falling On Our Planet (And Becoming Part Of Us)
As children, many of us probably heard of fairy dust, and although fairy dust doesn’t exist (unfortunately), Stardust does. According to National Geographic, every year the Earth is covered in 40,000 tonnes of cosmic dust (a mixture of various elements, including oxygen, carbon, iron, and nickel), resulting from the solar system forming. The dust is reported to fall on the Earth all the time and has since the very beginning.
Although we do not notice the 40,000 tonnes of cosmic dust, it is a part of us, as finds its way into our bodies.
21 The Sun Is 149 Million Kilometers Away, Although That Number Can Vary
Some facts about the Earth are very well-known, for example, most of us learn from an early age that the Earth is the third planet away from the sun. But just how far is that in kilometers? According to Thought Co., the distance between the Earth and the sun is 149 million km, but there are times when the Earth is slightly closer or further away from the sun, too, because as Space notes, the Earth’s orbit is not a perfect circle.
The time when the Earth is closest to the sun is called perihelion, this happens in January and is around 146 million km away, while the furthest away happens in July and is called aphelion. During the aphelion, the Earth is 152 million km from the sun.
20 Gravity Is Not Distributed Equally On Earth And There Are Some Places Where Anamolies Exist
In space, there is no gravity, and according to NASA (via Live Science), astronauts’ bone mass is affected by the lack of gravity, resulting in a loss of up to 1 percent of their bone mass per month while in space. Although gravity exists on Earth, it’s not all equal; different locations on Earth have varying degrees of gravity because the gravity is not distributed equally.
According to Live Science, this is because the Earth is not a perfect sphere (more on this later) and an example of the uneven distribution of gravity can be found in the Hudson Bay of Canada. The area has a lower gravity than other regions, and this is believed to be because of the glaciers (which formed during the Ice Age) which have since melted.
19 The Earth Is Not Perfectly Round, Despite How It May Look From Space
As mentioned above, the Earth is not a perfect circle and instead, it’s more of a sphere. According to Universe Today, the Earth is shaped like an oblate spheroid; flattened at the poles and bulging at the equator.
Isaac Newton was the first to suggest that the Earth was not perfectly round, Scientific American notes, and evidence of this can be seen in the difference between the distance from Earth's center to sea level, which is around “21 kilometers greater at the equator than at the poles.”
18 A Year On Earth Is Not Exactly 365 Days -- And That's Why We Have Leap Years
We typically think that every calendar year on Earth is made up of 365 days, but that’s not exactly true because according to Universe Today, every year there is 365.2564 days, meaning that there are an extra .2564 days (around 1/4 of a day more in a year).
If you think about it, then this makes sense because every four years we experience a Leap Year (and four quarter days equal one full day). A Leap Year consists of 366 days, and this is when the 29th day is added to the month of February.
17 The First Life Forms Date Back Around 3.8 Billion Years
Life has existed on Earth for billions of years, and according to Thought Co., the first evidence of life happened around 3.8 billion years ago. However, this was not life as we imagine it now, and these life forms were tiny microbial beings.
Live Science expanded on this thought, revealing that evidence of the earliest life forms has been found in rocks dating back billions of years. Among these rocks are those from Akilia Island in Greenland, which are believed by some scientists to contain evidence of “ancient metabolic activity” dating back 3.8 billion years.
16 Earth Is The Only Planet Not Named After A God Or Goddess
The planets in our solar system have interesting names, for example, Venus and Mars, but out of the eight names, it is only Earth that has not been named after a Greek or Roman god or goddess. According to Hello Giggles, the name Earth comes from the old English word, “ertha,” which simply means ground or land.
NASA expanded on this point, revealing that astronomy is an old science, but the International Astronomical Union (IAU) opted to keep the tradition of naming planets after Greek and Roman mythology. In more modern times, the naming of Uranus, Neptune, and Pluto (which has since been downgraded to a dwarf planet) reflected the trend.
15 Some Scientists Believe Our World Once Had Two Moons
Could there have been two moons when Earth was in its infancy? This is the belief of some scientists, who, according to Space, think that in addition to the moon we know today, there was once a second, much smaller moon (around 750 miles wide) that orbited the Earth. The theory is that these two moons collided, destroying the smaller moon, and could potentially be the explanation for the difference in the appearance of the two sides of our moon.
14 Depending On Where You Measure The Earth From, The Circumference Differs Slightly
The Earth is not a perfect sphere, and thus the circumference of it changes slightly, depending on where it is measured. According to Thought Co., when measured at the equator, the circumference of the Earth is 24,901.55 miles, but this number decreases slightly when measured at the poles, becoming 24,859.82 miles.
The publication also notes that the Earth is wider than it is tall, causing a slight bulge at the equator, and thus changing the shape from a perfect sphere to an ellipsoid.
13 In The Solar System, It Is Only Earth That Can Support Life (So Far)
Earth is a remarkable place, made even more remarkable by the fact that it is the only known planet with life. According to Space, although other objects in space, like Saturn’s largest moon Titan, seem to suggest that they could have once been host to some form of life, so far, no life outside of Earth has been found.
Earth is teeming with plant and animal life and this is possible because Earth has a number of features which are ideal for life, including having water in a liquid form on the planet’s surface -- believed to be linked to the distance from the sun, and its location is “just right.”
12 The Rock Cycle Means The Ground We Walk On Is Continually Changing
The ground that we walk on is recycled, and this is one of the most interesting things to know about the Earth. According to Live Science, this happens because of the Earth’s rock cycle, which is ever changing and involves three primary types of rocks: sedimentary, igneous, and metamorphic rocks.
These rocks are all formed in different ways, sedimentary is the compression of sediments, igneous are formed from the cooling of magma, and metamorphic are created from the partial melting of previous existing rocks, for example, sedimentary or igneous. According to Forbes, simply put the process of the rock cycle involves these rocks being created, changed from one type to another, and then being destroyed.
11 There Is Significantly More Water Than Land
The Earth is often referred to as the blue planet because of the large amount of water that exists on its surface, and most of us are familiar with the fact that the Earth has a large amount of liquid water. But do you know exactly how much more water on Earth there is that land?
The water to the land ratio found on Earth is far from equal, with around 70. 8 percent of the Earth covered in water, while just 29.2 percent is made up of land, Thought Co. reports.
10 The Chemical Composition On Earth Includes Four Main Elements
Earth has the ideal conditions to sustain life and we have already established that the planet consists of mostly water (which is one of those conditions), but the chemical composition, according to Thought Co. is “34.6 percent iron, 29.5 percent oxygen, 15.2 percent silicon, 12.7 percent magnesium, 2.4 percent nickel, 1.9 percent sulfur, and 0.05 percent titanium.”
According to Phys, Dr. Lineweaver stated that “working out exactly what the Earth is made of is tricky," but it seems the most abundant elements are agreed upon, and these are iron, oxygen, silicon, and magnesium. Universe Today notes that the majority of the iron is found in the Earth’s core, while the Earth’s crust, on the other hand, is 47 percent oxygen.
9 Most Of The Fresh Water On Earth Can Be Found In The Form Of Ice
As mentioned above, a large percentage of the Earth is made up of water, but, interestingly, around 96.5 percent of all Earth's water is located in the oceans, according to USGS. This means that the majority of the water found on Earth is saline, and although freshwater resources can be found in lakes, streams, rivers, and groundwater, the highest percentage of fresh water can be found in ice.
According to Science Daily, 90 percent of the world’s fresh water is in the Antarctic ice sheet, which is the single biggest mass of ice on Earth, and would account of the equivalent of“70 m of water in the world's oceans.”
8 There Are Some Places On Earth That Look As Though They Are From Another World Entirely
There are many places on the Earth that look as though they belong on another planet. National Geographic brings this to our attention by pointing out that there are places on Earth, like Ethiopia’s Danakil Depression, where life exists in seemingly uninhabitable circumstances. For example, the area is filled with lava lakes, poisonous gases, and hot springs, yet despite these conditions, there are certain organisms which thrive in the environment.
The area has been compared to life on Mars, and according to The Conversation, the organisms which live here provide evidence which “suggests that life can develop mechanisms to withstand physical and chemical conditions like those on the planet Mars.”
7 Climate Change Is Affecting Our Fresh Water Supply
Climate change is having a harmful effect on our planet, and among the many changes happening includes the loss of fresh water. Already most of our water supply is saline, so any threat to fresh water is something to be concerned about, and according to The Guardian, global warming is causing the polar ice caps to melt into the sea, which turns fresh water into sea water.
Higher temperatures can also melt inland glaciers, increase the amount of water that the atmosphere can hold, and can result in reduced rainfall in sub-tropics. Overall, this could result in global drought and changes to the water scale.
6 The Magnetic North Pole Is Moving At An Increasingly Fast Pace
The Earth has geographic north and south poles, as well as magnetic north and south poles, based on the Earth’s magnetic field, How Stuff Works reports. These poles can also switch places, and according to NASA, since the 19th Century, the magnetic north pole has been moving northward.
Thus far, it is believed to have moved more than 1,100 kilometers. It also seems to be moving at a faster pace now, at a rate of about 64 km per year.