science of the earth


The Earth completes one orbit every 365.242199 mean solar days(that might help explain the need for a leap year).

Earth, our home, is the third planet from the sun. It is the only planet known to have an atmosphere containing free oxygen, oceans of liquid water on its surface, and, of course, life. Earth is the fifth largest of the planets in the solar system — smaller than the four gas giants, Jupiter, Saturn, Uranus and Neptune, but larger than the three other rocky planets, Mercury, Mars and Venus. Info from space.com

Earth's Circumference at the Equator: 24,901.55 miles (40,075.16 km) Earth's Circumference Between the North and South Poles: 24,859.82 miles (40,008 km) Earth's Diameter at the Equator: 7,926.28 miles (12,756.1 km) Earth's Diameter at the Poles: 7,899.80 miles (12,713.5 km) Average Distance from the Earth to the Sun: 93,020,000 miles (149,669,180 km)

Earth, of course, can be studied without the aid of spacecraft. Nevertheless it was not until the twentieth century that we had maps of the entire planet. Pictures of the planet taken from space are of considerable importance; for example, they are an enormous help in weather prediction and especially in tracking and predicting hurricanes. And they are extraordinarily beautiful.

Earth is the third planet from the Sun and the fifth largest planet in the Solar System. It is the largest of the four inner rocky planets and the densest major body in the Solar System. Earth is the only planet whose English name does not derive from Greek/Roman mythology. The name derives from Old English and Germanic. There are, of course, hundreds of other names for the planet in other languages. It was not until the time of Copernicus (the sixteenth century) that it was understood that the Earth is just another planet.

Earth was originally born as a twin to the planet Theia, which was about half as wide as Earth and roughly the size of Mars. The two planets shared an orbit for several million years until they collided. Earth absorbed Theia, and the remaining debris eventually coagulated into Earth’s moon. The mass donated by Theia gave Earth the gravity necessary to sustain a substantial atmosphere.

Earth can be seen as a living, breathing organism: it regulates temperature, burns energy, continually renews its skin, and experiences changes to its face as it ages with time.

Our planet's rapid spin and molten nickel-iron core give rise to a magnetic field, which the solar wind distorts into a teardrop shape. The solar wind is a stream of charged particles continuously ejected from the sun. The magnetic field does not fade off into space, but has definite boundaries.

Earth is the third planet from the Sun, and the densest and fifth-largest of the eight planets in the Solar System. It is also the largest of the Solar System's four terrestrial planets.

The Earth’s shape could be described as an oblate spheroid. It’s kind of like a sphere, but the Earth’s rotation causes the equator to bulge out . What this means is that the measurement from pole to pole is about 43 km less than the diameter of Earth across the equator. Read more: http://www.universetoday.com/14382/10-interesting-facts-about-planet-earth/#ixzz2BSjzmWJe