EVERYDAY SCIENCE

Detailed explanation-1: -The moon takes about 27.3 days to revolve round the earth in a nearly circular orbit of radius 3.84×105 km.

Detailed explanation-2: -Period of the orbit is about 27.3 days. This is called the SIDERIAL PERIOD or SIDEREAL MONTH. This is measured with respect to the background stars: the moon takes 1 sidereal period to cycle around once. In its eastward motion, the moon stays near the ecliptic.

Detailed explanation-3: -It takes 27 days, 7 hours, and 43 minutes for our Moon to complete one full orbit around Earth. This is called the sidereal month, and is measured by our Moon’s position relative to distant “fixed” stars. However, it takes our Moon about 29.5 days to complete one cycle of phases (from new Moon to new Moon).

Detailed explanation-4: -It takes the Moon 27.3 days to make a complete orbit around the Earth, but because the Earth is moving around the sun at the same time, it takes the moon 29.5 days to go through its eight different ‘phases’ – a lunar month.

Detailed explanation-5: -The moon completes one (circular) orbit of the earth in 27.3 days. The distance from the earth to the moon is 3.84×108m.