The Solar System Wiki

Earth spacepedia.png
Name of Planet Earth
Number of Sattelites 1
Discovered by 240 BCE by Eratosthenes
Atmospheric Makeup 78% nitrogen,
20.5% oxygen
0.9% argon
0.04% carbon dioxide
Distance from Sun 93 million miles from the Sun (1 astronomical unit)
Diameter 7926 miles
12,756 kilometers
Axial tilt 23.4 degrees
Orbit 365.25 (1 year) Earthen days
Position in Solar System Third planet from Sun
Surface Features 29.2% land 70.8% water
Albedo (geometric) 0.367
(bond) 0.306
Aphelion 95.06 million miles
Perihelion 91.936 million miles
Mass of Planet 5.974 x 10^24 kg
Escape Velocity 11.12 kilometers/second

Earth is the third planet from the Sun. It is the only planet known to support life nowadays. Liquid water makes up 71% of Earth's entire surface, and only 29% is solid land. Earth is the largest terrestrial planet and is the fifth largest planet, with the fifth largest natural satellite. It is home to a sapient race of organisms referred to as Modern Humans, or Homo Sapiens scientifically. They have a population of 7.9 billion and is currently causing an ongoing period of geographic mass extinction on Earth.


The Earth formed from a clump of rocky materials and particles about 4.54 billion years ago. It was a molten planet with extreme volcanic activity and had an atmosphere composed mostly of hydrogen and helium, similar to that of the Sun and Jovians' atmosphere composition.

Around 4.53 billion years ago, a massive Earth trojan planet referred to as Theia, came in an unstable orbit around Earth and caused a catastophic collision event. This collision completely obliterated Theia and ripped off Earth's outer crust, throwing back the leftover debris into a planetary ring system, like Saturn. The ring system later clumped together into a molten ball of rock and debris which would be now known as the Moon.

Earth's Sister Planet[]

Venus, the Earth's neighboring planet, is classified as its sister due to its similar size and shape. However, they're very different from each other. Venus has ongoing volcanic activity and a thick atmosphere which traps heat on the surface, making a catastrophic greenhouse effect on the entire planet and making life impossible. Earth, on the other hand, is 70.6% water and has an atmosphere of oxygen and nitrogen, unlike Venus.

Atmospheric Makeup[]

The Earth's atmosphere is mostly made of nitrogen. In fact, more than three fourths of the atmosphere is nitrogen. Oxygen makes up just more than one-fourth of the atmosphere. The rest is made up of less than one percent argon and carbon dioxide.

The atmosphere is split into two main layers: the troposphere and the stratosphere. The troposphere is the closest layer of the atmosphere to us. All of the weather on Earth occurs in this layer. The stratosphere is the lowest layer of the mesosphere, and is where the temperature of the atmosphere begins to increase due to the absorption of ultraviolet radiation from the Sun. This layer is also rich with ozone, for it contains a portion of the ozone layer.

Other layers include the mesosphere, the region in the atmosphere at which the temperatures drop to below -100 degrees Fahrenheit due to radiation being reflected away from this layer into the stratosphere. This layer is where the majority of the ozone layer is found. The ozone layer is the layer created by the build up of ozone, which is a gaseous substance that absorbs most of the ultraviolet radiation from the Sun.

Clouds are another addition in the atmosphere. These occur when air in the troposphere begins to rise and then fall. The cool air falls since it is more dense and the warm air rises because it is less dense. This process is called convection. When water vapor rises, it becomes heated and continues rising because it becomes less dense. Then, once it rises above the clouds, it cools and condenses, becoming clouds.

Name Oceans Water Creating Creating Year Created Thing Life
Earth Salty With Meteors 4,542,997,979 BC Asteroid Yes


Internal Structure[]

Tectonic Plates[]

Satellites that orbited Earth[]

Spacecraft Organization Date Distance
Giotto ESA 2 July 1990 22,730 km
Galileo NASA 8 December 1990 301 km
Sakigake ISAS 8 January 1992 88,790 km
Suisei ISAS 20 August 1992 failure
Galileo NASA 8 December 1992
Sakigake ISAS 14 June 1993

28 October 1994

NEAR Shoemaker NASA 23 January 1998 540 km
Nozomi ISAS 20 December 1998 1000 km
Giotto ESA 1 July 1999 failure
Cassini NASA



18 August 1999 1171 km
Stardust NASA 15 January 2001 6000 km
Nozomi ISAS December 2002

19 June 2003

11,000 km

1000 km

Hayabusa ISAS 19 May 2004 20,000 km
Rosetta ESA 4 March 2005 1950 km
MESSENGER NASA 2 August 2005 2348 km
Stardust NASA 15 January 2006
Rosetta ESA 13 November 2007
Deep Impact NASA 31 December 2007

December 2008

15,567 km

43,450 km

Stardust NASA 14 January 2009 9200 km
Rosetta ESA 13 November 2009
Deep Impact NASA June 2009

December 2009

June 2010

36,900 km
Juno NASA 9 October 2013 559 km
Hayabusa 2 JAXA 3 December 2015
PROCYON University of Tokyo


3 December 2015
Shin'en 2 Kyutech 4 December 2015
OSIRIS-REx NASA 22 September 2017 17,237 km


It's Only Owned Lifes

The internal structure of Earth

Tectonic plates are the makeup of the lithosphere. These plates can be 60 km thick and are the plates that drive the continents. These plates can join together to form boundaries. Some boundaries can cause geographical features such as mountains when they collide and push up the crust plate (convergent boundary), some can cause earthquakes when they slide against each other causing tension (transform boundary), or seafloor spreading when two plates move away from one another (divergent boundary).

Due to this, there is a process called continental drift. Continental drift was founded by Alfred Wegener, and involves all of the continents moving about the Earth, but the change is so small, it is undetectable by humans. This theory proves that Pangaea existed more than 250 million years ago. Pangaea was a supercontinent that combined all of the known continents we know today. Through the process of continental drift, Pangaea split up after going through several changes and shifted into the places the continents are in today.

Orbit and Rotation[]

Earth's orbit takes one Earthern year. This is equal to 365.25 Earthern days. With the extra one-fourth, every four years, the one-fourth becomes a whole and adds an extra Earthern day, making it a leap year.

Earth takes 23 hours, 57 minutes to make one rotation on its axis. This number is mostly rounded to what we know as 24 hours in one Earthen day.


Earth has one moons (two temporary), Moon, S509356, and YX205B9.



Dwarf Planets