The Physical Environment
                                                   Contents | Glossary | Atlas |  Index | TPE Today | Google Earth | Search

 Earth System

The Earth System

A system is defined as a collection of interacting objects. The earth is a component of the solar system, which consists of the Sun and the celestial objects bound to it by gravity. Though Earth has relatively little interaction with the other planets, the Sun and the Earth's moon indeed do. The earth system receives receives energy from Sun, and gravitational attraction holds the Moon in an orbit around the Earth. The gravitational pull of the Moon on Earth's oceans creates tides as we'll see in Chapter 21 "Ocean and Coastal Systems". Let's begin an investigation of the earth system by examining the origin of the earth, its basic components, and its most important source of energy, the Sun.

Birth of the Solar System

Earth is the third planet from the Sun, one of eight "classical" planets recognized by the International Astronomical Union in our solar system. A planet must orbit the Sun, be big enough that gravity pulls it into a round ball, and must have other things out of its orbital path. Pluto, defined as a planet until 2006 but was declassified as it orbits among the icy bits of the asteroid belt. In 2008 it was classified as a "plutoid", a kind of dwarf planet.

solar system

Figure 2.1 The Solar System
Courtesy NASA (Source)

 

It is thought that the planet like Earth originated from the accretion of bits of solispiral galaxyd matter left from the massive explosion of a star or supernova. Bits of material were scattered into space forming a slowly rotating cosmic gas cloud. Gravity slowly gathered the thinly spread atoms of the cosmic cloud. As the atoms moved closer together the gas became hotter and more dense. A new sun was born as hydrogen eventually became so tightly compressed and temperatures so high that nuclear burning began. A flattened rotating disc of gas and dust surrounded the young sun. Outer cooler parts of the disc or star nebulae began to condense to form the building blocks of future planets.

Figure 2.2 Image of the spiral galaxy NGC 4414 (Source: NSSDC NASA)

 

Video: "Birth of the Solar System"

Courtesy National Geographic

Previous | Continue     


 

Contents |Glossary | Atlas Index  |  Blog | Podcast | Google Earth | Search Updates | Top of page

About TPE | Who's Used TPE |  Earth Online Media

Please contact the author for inquiries, permissions, corrections or other feedback.

For Citation: Ritter, Michael E. The Physical Environment: an Introduction to Physical Geography.
Date visited.  https://www.earthonlinemedia.com/ebooks/tpe_3e/title_page.html

Michael Ritter (tpeauthor@mac.com)
Last revised 6/5/12

Help keep this site available by donating through PayPal.

paypal

Creative Commons License
This work is licensed under a Creative Commons Attribution-ShareAlike 4.0 International License..