Facts about Earth~~Happy Earth Day~~04/12

1. The Earth is around 4.6 billion years old.
2. The Earth is the densest planet in the Solar System.
3. The Earth’s atmosphere is composed mainly of nitrogen (78%), oxygen (21%), argon (.93%), and carbon dioxide (0.03%).
4. Earth’s atmosphere divided in 5 sections from the surface: Troposhere (0-13 km), Ozone Layer (13-25 km), Stratosphere (25-50 km), Mesosphere (50-75 km), and Thermosphere (75-150 km)
5. Earth is the fifth largest planet in the Solar System.
6. The Diameter of the Earth is 12,756 km (7,926 miles)
7. The earth’s orbital speed is 29.8 km per second.
8. Earth has only one satellite, the Moon. The Moon is the second brightest object in the sky from Earth.
9. Earth has an average surface temperature of 13 degrees C (55.4 degrees F).
10. The greenhouse effect raises Earth’s temperature 35 degrees C (95 degrees F).
11. Earth’s distance from the Sun – Min. 146 million km (91million miles) Max. 152 million km (94.5 million miles).
12. Earth is composed of: iron (32%), oxygen (30%), silicon (15%), magnesium (14%), sulfur (3%), nickel (2%), calcium (1.5%), aluminum (1/4%) and the remainder made up of other elements.
13. Earths main tectonic plates: African plate, Antarctic plate, Indo-Australian Plate, Eurasian Plate, North American Plate, South American Plate, and the Pacific Plate.
14. Earth has several layers with unique chemical and seismic properties: Crust (0-40 km), upper mantle (40-400 km), transition region (400-650 km), lower mantle (650-2700 km), D layer (2700-2890 km), outer core (2890-5150 km), and the inner core (5150-6378 km) from the surface.