Earth is a sphere comprised of molten rock under the crust of the outer planets. The innermost edge of Earth is covered with lava and is referred to as the “moon.” This outer layer also contains much of Earths natural heat, which helps keep it cool. While it may be very cold, Earth is the most abundant of the planets in our solar system.


Earth was created in its current state by a large planet which crashed into the earth causing its volcanoes, tectonic plates and core, and liquid metal elements to boil into liquid below the earth’s surface. It is a very important place in our solar system and is considered to be a habitable planet, with oceans and lakes that may be full of oceanic life and rivers that could feed or support the plant and animal life that exists on Earth. Although it is very hot, Earth is a “very cold” planet which has the lowest temperature of any planet in our solar system. Earth is constantly bombarded with solar radiation and solar wind which contribute to the high heating of the planet.

The composition of the earth is primarily composed of silica, feldspars, and other rocky or grainy metallic elements. It also consists of other elements which are less common. Earth also contains an element known as silicates which is the most common element in the crust of the earth apart from sulfur and oxygen. There are several theories about how life began on earth including the concept of panspermia, in which life began in separate bodies of water on different planets.

Recent earth system scientists have suggested that a large collision between two space craft traveling to other galaxies may be responsible for the formation of the first planets. Evidence suggests that a large collision occurred close to the dwarf galaxy NGC 4342. This is an unusual and perhaps the first celestial collision that has been linked to the birth of life on earth. Evidence suggests that these collisions led to the building up of huge amounts of gas and rock which later became the planet Earth. Scientists have theorized that these collisions were responsible for the rise of atmospheric oxygen and carbon dioxide, the greenhouse effect, and eventually the development of complex life forms like fish and land animals.

The study of earth science is part of the larger field known as planetary science. This discipline studies the effects of space debris and other natural phenomenon on our earth and attempts to find out whether they play a role in affecting climate cycles. Scientists have speculated that the large meteorite impact which killed off the dinosaurs may be responsible for setting the pace for the rise of the ice age. By studying earth’s orbit, the wobble in the inner atmosphere of the earth, and the concentration of water vapor in the atmosphere, the scientists are attempting to solve a puzzle that has eluded generations of geologists.

The study of earthlings has given rise to several theories on the formation of the first planets. Though many in the scientific community doubt the theory of an earth-sized planet forming around a sun-like star, theories about a super giant planet circling the much dimmer and very distant sun continue to attract adherents. Although it is not clear how life began on earth, one scientist has said that abiogenesis, or the production of life by a living organism without a exoskeleton, might be necessary for the emergence of life on earth. Another scientist has suggested that abiogenesis is necessary for the development of green algae that would eventually lead to the development of the first oxygen-based atmosphere on earth.