Earth is the third closest planet to the Sun at a distance of about 150 million kilometers (93.2 million miles). It takes 365.256 days for the Earth to travel around the Sun and 23.9345 hours for the Earth rotate a complete revolution. It has a diameter of 12,756 kilometers (7,973 miles), only a few hundred kilometers larger than that of Venus. Our atmosphere is composed of 78 percent nitrogen, 21 percent oxygen and 1 percent other constituents.
also called as Terra and Tellus. Its astronomical symbol consists
of a circled cross, representing a meridian and the equator;
a variant puts the cross atop the circle. Besides words derived
from Terra, such as terrestrial, terms that refer to the Earth
include tellur- (telluric, tellurian, from the Roman goddess
Tellus) and geo- (geocentric, geothermal; from the Greek goddess
an Old English and German word, it was 'ertha' in Old Saxon,
'aerde' in Dutch, and 'erda' in German, it simply means 'land'.
Earth's atmosphere protects us from meteors, most of which
burn up before they can strike the surface.