Earth is the third planet from the Sun and largest of the terrestrial planets. Surprisingly, while it is only the fifth largest planet in terms of size and mass, it is the densest (5,513 kg/m3) of all the planets.
Earth was formed somewhere around 4.543 billion years ago– almost one-third of the age of the universe and is currently the only known planet to support life – and lots of it.
- Population: 7.53 billion (2017) Trending, World Bank
- Distance from Sun: 92.96 million mi
- Radius: 6,371 km/3,959 miles
- Polar Radius: 6,356 km/3.949 miles
- Orbital Period: 365.24 days
- Mass: 5.972 × 10^24 kg
- Surface Area: 510 million km2/197 million miles2
- Volume: 1 trillion km3/ 260 billion miles3
- Number of Moons: 1
How much does the average person really know about the planet Earth? You’ve lived on Planet Earth all of your life, but how much do you really know about the ground underneath your feet? So read and find it out yourself!!
The Earth is believed to have formed around 4.543 billion years ago and the duration for this formation has been estimated to have lasted around 10-20 million years.
Slowly, the Earth’s atmosphere and oceans were formed by volcanic activity and out-gassing.So, it is believed that water vapour condensed into the oceans being increased by water and ice from asteroids, protoplanets and comets.
The atmospheric greenhouse kept the oceans from freezing when the newly formed Sun had only 70% of its current luminosity. When the Earth’s magnetic field was established it helped to prevent the atmosphere from being stripped away by the solar wind.
A crust formed when the molten outer layer of Earth cooled to form a solid. There are two models who propose that the landmass steadily grew to present-day forms, or, more likely that it grew rapidly early in Earth’s history, followed by a long-term steady continental area. The continuous loss of heat from Earth’s interior, helped continents form through – plate tectonics.
Through periods of hundreds of millions of years, the supercontinents have assembled and then broke apart and then about 750 million years ago, the earliest known supercontinent Rodinia began to break apart.
The continents later rejoined and as a result combined again to form Pannotia about 600 to 540 million years ago. This happened again and the supercontinent of Pangaea formed but also broke apart about 180 million years ago.
These are patterns that suggest that ice ages began about 40 million years ago. t is believed that the last continental glaciation ended 10.000 years ago.
Similar to the other terrestrial planets, Earth’s interior is believed to consist of three components: a core, a mantle, and a crust. At present, the core is thought to be comprised of two separate layers— inner core composed of solid nickel and iron, and an outer core composed of molten nickel and iron.
The mantle is very dense and almost entirely solid silicate rock; its thickness is roughly 2,850 km. Finally, the crust is also composed of silicate rock and varies in thickness. While the continental crust ranges from 30 to 40 km in thickness, the oceanic crust is much thinner at only 6 to 11 km.
Furthermore, these plates are in constant motion. Along the boundaries of these plates two processes, known as subduction and spreading, can occur. During subduction two plates come into contact (sometimes violently, producing earthquakes) and one plate is forced under the other. While on the other hand, separation is when two plates are moving away from each other.
Distance and Size
Depending upon their current orbital positions, either Venus or Mercury are the closest planets to Earth. It has an equatorial radius of 6.371 km / 3.958 mi, and a polar radius of 6.356 km / 3.949 mi, which meaning it is not completely spherical but rather bulged at the equator due to rotation.
The diameter of Earth is around 12.756 km / 7.917 mi being the fifth largest planet from the solar system, and the largest of the terrestrial planets (Venus, Mercury, Mars).
The Earth is so big that almost 50 moons could fit inside it. Earth has a mass of about 6.6 sextillion tons and a volume of about 260 billion cubic miles / 1 trillion cubic kilometers.
Orbit and Rotation
It actually takes 23 hours, 56 minutes and 4 seconds for the Earth to rotate once completely on its axis, which astronomers refer to as a Sidereal Day.It takes Earth 365.25 days to complete one trip around the Sun.In order for calendars to maintain their consistency with this orbit, every 4 years one day is added – this is called a leap day – as well as a leap year.
But remember that the Earth orbits around the Sun. Every day, the Sun moves compared to the background stars by about 1° – about the size of the Moon in the sky. And so, if you add up that little motion from the Sun that we see because the Earth is orbiting around it, as well as the rotation on its axis, you get a total of 24 hours.
Earth’s orbital speed averages 29.78 km/s (107,208 km/h; 66,616 mph), which is fast enough to cover the planet’s diameter in 7 minutes and the distance to the Moon in 4 hours.
The atmosphere of Earth is a layer of gas above the crust. Earth’s atmosphere is thickest within the first 50 km from the surface or so, but it actually reaches out to about 10,000 km into space.It is not solid and thus it fades away with height. Karman Line is the line between Earth’s atmosphere and space which is about 100 km / 62 miles up. Technically, anyone, who goes above it is an “astronaut.”
The bulk of the Earth’s atmosphere is down near the Earth itself. In fact, 75% of the Earth’s atmosphere is contained within the first 11 km above the planet’s surface. However, the outermost layer (the Exosphere) is the largest, extending from the exobase – located at the top 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 emptiness of outer space, where there is no atmosphere.
The ozone layer is situated at a height of 25 km / 15.5 mi on average. This is a molecule of oxygen that absorbs very well solar ultraviolet light. This type of light is dangerous to biological molecules thus the ozone layer is critical for our protection and survival.
The atmosphere of Earth comprises of roughly 78% nitrogen, 21% oxygen, 0.97% argon and carbon dioxide and about 0.04% other gases and water vapor. The mixture of gases is commonly known as air.
The atmosphere of Earth is divided into 6 major layers:
(1). Troposphere – The lowest starting at ground level and extending upward to about 10 km / 6.2 miles. Most of the weather occurs here and most clouds are present.
(2). Stratosphere – It extends from the top of the troposphere to about 50 km / 30 miles above the ground. This is where the ozone layer is present. Unlike the troposphere, it gets warmer upwards which means a lack of turbulence for commercial jet plane rides.
(3). Mesosphere – It extends upward to a height of about 85 km / 53 miles above the surface of the Earth. Most of the meteors burn up in the mesosphere and unlike the stratosphere, the temperature drops again with the top temperature reaching about -90 degrees Celsius / -130 degrees Fahrenheit.
(4). Thermosphere – A layer with very rare air and high-energy X-rays and radiation from the Sun being present but absorbed by the thermosphere. This raises the temperatures considerably and most satellites orbit the Earth in this layer. The top of the thermosphere varies between 500-1.000 km / 311-621 miles above the ground.
(5). Exosphere – Considered the final frontier of Earth’s gaseous envelope. The air here is extremely thin and leaks into space. The top once again varies: 100.000-190.000 km / 62.000-120.000 miles above the surface of Earth.
(6). Ionosphere – It is not a distinct layer as the previous ones. It is rather a series of regions in parts of the mesosphere and thermosphere where high-energy radiation from the Sun has knocked electrons loose from their parent atoms and molecules.
How did Earth got its name?
If you notice, Earth is the only planet not named for a mythological god or goddess. The other seven planets in the solar system were named after Roman and Greek gods or goddesses. This Roman method was also used after the discovery of Uranus and Neptune.
Another thought is that the name “Earth” is derived from the Old English word “ertha” as well as the Anglo-Saxon word “erda”, which means soil or ground.
You probably have lots of interesting facts rattling around in your brain, but here are 10 more interesting facts about Earth that you may, or may not know.
1. 70% of the Earth’s Surface is Covered in Water
When astronauts first went into the space, they looked back at the Earth with human eyes for the first time. Based on their observations, the Earth acquired the nickname the “Blue Planet” and it’s no surprise, seeing as how 70% of our planet is covered with oceans. The remaining 30% is the solid crust that is located above sea level, hence why it is called the “continental crust”.
2. The Earth’s Molten Iron Core Creates a Magnetic Field
The Earth is like a great big magnet, with poles at the top and bottom near to the actual geographic poles. The magnetic field it creates extends thousands of kilometers out from the surface of the Earth – forming a region called the “magnetosphere“. Scientists also think that the molten outer core of the Earth generates this magnetic field, where heat creates convection motions of conducting materials to generate electric currents.
Be grateful for the magnetosphere. Without it, particles from the Sun’s solar wind would hit the Earth directly, and it would expose the surface of the planet to significant amounts of radiation. Instead, the magnetosphere channels the solar wind around the Earth, protecting us from harm. Scientists estimates that Mars’ thin atmosphere is due to it’s weak magnetosphere as compared to Earth’s, which allows solar wind to slowly strip it away.
3. A year on Earth isn’t 365 days
It’s actually 365.2564 days. It’s this extra .2564 days that creates the need for a Leap Year once ever four years(.25*4 = 1 day). So that’s the only reason we tack on an extra day in February every four years – 2004, 2008, 2012, 2016, etc. The exceptions to this rule is if the year in question is divisible by 100 (1900, 2100, etc), unless it is divisible by 400 (1600, 2000, etc).
4. Earth is the Only Planet Having Life
Scientists have discovered past evidence of water and organic molecules on Mars, and the building blocks of life on Saturn’s moon Titan and we can see amino acids in nebulae in deep space. Scientists have also speculated about the possible existence of life beneath the icy crust of Jupiter’s moon Europa and Saturn’s moon Titan. But Earth is the only place having life.
But if there is life on other planets, scientists are building the experiments that will help find it. For instance, NASA just announced the creation of the Nexus for Exoplanet System Science (NExSS), which will spend the coming years going through the data sent back by the Kepler space telescope (and other missions that have yet to be launched) for signs of life on extra-solar planets.
5. 95% of Our Oceans are Unexplored
While space is considered the “final frontier” for many, there is a much closer region of our solar system that remains unexplored: our oceans.About 95 per cent of the ocean hasn’t been explored.
The problem is two-fold: one, our oceans are vast, accounting for more than 70 per cent of our planet. And another is that accessing regions is difficult for us: we weren’t built to live under water, so tools and technology are needed to assist us.
6. Highest and deepest points on Earth
The highest point: The closest point to space on Earth is not Mount Everest. Rather it is Mount Chimborazo, a 20,000 plus foot mountain in the Andes. Even though Mount Everest is taller from sea level. At this point, the Earth’s bulge is greatest.
The deepest known place: The deepest known place on Earth is “Challenger deep” – near a trench named as “Mariana Trench” beneath the surface of the Pacific Ocean to the southeast of Japan. This trench is nearly 10.9 km below sea level, it is further than the peak of Mount Everest.
7. Hottest and coldest locations
The highest recorded temperature: The hottest recorded temperature location on the Earth is in El Azizia, Libya with temperatures hitting 136 degrees F/57.8 degrees C in 1922.
The coldest permanently inhabited place: The coldest temperature ever recorded on Earth was at Antarctica’s Vostok station-(-89.2 degree Celsius).
8. Wettest and driest places
Wettest place: Mawsynram in Meghalaya, India is the wettest place on land on Earth. It receives an average annual rainfall of 11,871 mm. This place is just 10 miles away from the town of Cherrapunji (another record holder for the wettest month and year ever.)
Driest place: Dry Valleys in Antarctica is the driest place on Earth because this place has seen no rainfall for the past 2 million years and this is a 4800 square kilometer region with no ice, snow or water.
9. Longest River on Earth
The Nile is the longest river on Earth that extends 6,695 km from its source in Burundi to the Mediterranean sea. But Amazon is the biggest river in the world in terms of the water that flows down it.
10. Carbon Dioxide Spitting Lakes
There are three crater lakes – Nyos, Monoun, and Kivu, that sits in Cameroon and on the border of Rwanda and the Democratic Republic of Congo. These lakes spit carbon dioxide at an enormous level and have been the cause of deaths of hundreds of people in the past. This phenomenon happens because of the presence of magma below the surface of the lakes and this magma releases carbon dioxide into the water which causes the resulting spewing of the gas into the atmosphere.
There is a possibility that some asteroid/comet may hit earth and cause devastation to life. A similar event 65 million years ago happened and wiped out the dinosaurs from the planet.
11. The Oceans Hold $771 Trillion Worth of Gold
Not that you’d be able to get at any of it. But scientists estimate that the oceans of the world contain approximately 20 million tons of gold. Not on the ocean floor—in the water itself, in tiny particles of approximately 13 billionths of a gram per liter.
12. The Greatest Vertical Shift Is in Canada
If you’re looking for a seriously steep cliff, you’ll find it on Canada’s Baffin Island in Auyuittuq National Park in the northern part of the country. It’s name is Mount Thor and it has a 4,000-foot rock face that has proved daunting for climbers, with 30 attempts made before a four-man team from America finally succeeded in 1985 (it only took them 33 days).
13. The Deepest (Non-Ocean-Covered) Place on Earth Is in Antarctica
Technically it is under deep layers of ice so ocean does not cover it…The Bentley Subglacial Trench in Antarctica goes down 8,382 feet below sea level.
14. The Largest Earthquake in the World Hit Chile
The worst earthquake to ever hit the Earth struck Chile on May 22, 1960. The 9.5-magnitude quake in Valdivia,Chile killed as many as 6,000 people and left 2 million people homeless, according to the Chilean government.
15. Hawaii Is Also Home to the Most Active Volcano
Speaking of Hawaii, the Aloha State also is where you will find Kilauea, the most active volcano on Earth, with 61 eruptions recorded in its current cycle, according to the U.S. Geological Survey and it’s been erupting continuously since 1983.
16. The rotation of the Earth is gradually slowing down
The deceleration of the Earth’s rotation is very slow, approximately 17 milliseconds per hundred years. Eventually this will lengthen our days but it will take around 140 million years before our day will have increased from 24 to 25 hours.
17. Protector of Earth
The Earth has an Ozone Layer which protects it from harmful solar radiation.This shell is a special type of oxygen that absorbs most of the Sun’s powerful UV rays.
18. Have you ever wondered why we have different seasons?
I’ll tell you –– it’s because the Earth is tilting 23.4 degrees on its ‘axis’ and an imaginary line straight through the middle of the planet forms the North Pole to the South Pole. This means that different parts of the globe are slanting towards the sun at different times of the year (or at different times during its orbit).
19. The water is 3% fresh and 97% salted. In that 3% freshwater, ice sheets and glaciers comprises over 2%. So it means that lakes, rivers, and the underground includes less than 1% freshwater.
20. In regards to land, the continent of Asia covers about 30% of all the land and it also has around 60% of the world’s population.
21. Why do we have daytime and nighttime?Not only does Earth zoom through space, it also spins on its axis. As the planet rotates, the side facing the sun receives daylight and the the other is in darkness.
22. There is a ‘garbage patch’ in the Pacific Ocean that is just a twisting and turning vortex of trash and waste. Its size is twice of continental American and it can contain nearly 100 million tons of garbage.
23. The queen of the UK is the owner of one-sixth of the Earth’s land surface.
24. One-third of Earth’s land surface is moderately or entirely desert.
25. If the Earth did not have the moon, our days would only be 6 hours long.
26. Seven-hundred-million years ago, the entire Earth was covered in ice.
27. Hawaii is moving towards Japan at the speed of 10 cm a year because they are on different tectonic plates.
28. The Niagara Falls are located on the border of the USA and Canada.
29. Rock found at the bottom of the Grand Canyon is around 2 billion years old.
30. America’s forests are reducing for building materials and fuel. So, only 4% of America’s forests are remaining now.
31. We only use 11% of the Earth’s surface to grow food.
32. We gain 77 million people each year, which means that the needs are rising and the resources are reducing.
33. It is a fascinating fact to note here that 99% of all species that existed on the Earth are now extinct.
34. The thickest of all the four layers of the earth is the mantle because it is 2900 kilometers thick. This layer has a consistency of caramel and comprises of a hot mixture of molten rock.
35. There is enough gold in the Earth’s core to cover the entire surface of the Earth in 1.5 feet of the sparkling mineral.
36. The longest known cave system on earth is the Mammoth Cave in Kentucky. It stretches for more than 390 miles, and that’s just what has been explored. Scientists believe it may be over 600 miles long.
37. The temperature of the Earth’s core is 5,500 degrees Celsius. As hot as the sun!
38. Earth’s Amazon rainforest is home to one third of the planet’s land species.
39. The Earth’s plates move just a few inches a year—about as fast as a person’s fingernails grow. This continental pattern predicts that 250 million years from now, a new supercontinent will be born.
40. Mount Augustus in the Australian Outback is the largest rock on Earth. So,it can be seen from almost 100 miles away and is about 2,352 feet high.
41. There is no solid land under the North Pole, just sea ice.
42. Antarctica has little vegetation and a snowy landscape. So it is one of the best places to find meteorites because most meteorites have been found in Antarctica than anywhere else in the world.
43. The tallest waterfall on Earth is Angel Falls, which is 3,212 feet high. It is as tall as a 300-story building.
44. Lake Baikal in Russia holds 20% of Earth’s unfrozen freshwater and it is the deepest and oldest lake in the world.
45. The tallest known tree on Earth is a redwood tree in a California forest because it is about twice as tall as the statue of liberty, at 380 feet high.
46. Antarctica holds about 90% of the Earth’s ice and 70% of Earth’s fresh water. Sea levels on Earth would rise about 60 m (200 ft) if all the ice in Antarctica were to melt.
47. The world’s largest desert, outside of the polar regions, is the Sahara Desert. This massive desert covers about 1/3 of Africa.
48. The Sun is considered to be an average-sized star, but 1 million Earths could fit inside.
49. Point Nemo (Latin for “no one”) lies at least 2,688 km (1,670 mi) from the nearest land so it is the most remote location on Earth and it is located in the Pacific Ocean.
- If there were a tunnel through one end of the earth to another, then it would take about 42 minutes to fall all the way through.