Some useful information about Earth What is the shape of the path in which the earth moves around the sun An elliptical path. What is a leap year ? Such a year which has 366 days, is called a leap year. Every fourth year is a leap year. The month of February has 29 days instead of 28 in a leap year. On which day all places on the northern hemisphere have the longest day and the shortest night ? On 21th June. On which day, all places on the southern hemisphere have the longest day and the shortest night? 22nd December What is autumnal equinox ? On September 23, days and nights become equal all over the world, this is called autumnal equinox. What is vernal equinox ? On 21 March, all places on the earth have equal days and nights, this is called vernal equinox In which direction the earth moves ? From west to east. What is the circle of illumination ? The circle which divides the earth into a light half and a dark half is called the circle of illumination. At what speed the earth revolves around the sun ? 29.8 kilometer/second or about 1,00,000 kilometer/hour. How much time the earth takes to complete one revolution ? 365 days and 6 hours, this period of time is called one year. At which place the duration of day and night is equal throughout the year ? At any place on the equator Why the days and nights are unequal on the earth ? Because the earth's axis is tilted. What is the average distance from the Earth to the Moon? 238,857 miles (384,403.1 km) What is the average distance from the Earth to the Sun? 93,020,000 miles (149,669,180 km)