Question

Which of the following is not a cause of Nutation?

a) Ellipticity of the Earth's orbit around the Sun

b) Ellipticity of the Moon's orbit around the Earth

c) Non-coincidence of the moon's orbit with the ecliptic

d) Non-coincidence of the Earth's equatorial plane with the ecliptic

Answer 1

Answer)

'Non-coincidence of the moon's orbit with the ecliptic' is not a cause of nutation.

Ellipticity of the Earth's orbit around the Sun. Earth orbit around the sun is elliptical with the speed of 108,000 km/h. Ellipticity of the Moon's orbit around the Earth. The orbit of the Moon is about 385,000km from the earth. It completes one revolution around the earth in 27.32 days with the speed of 3683km/h. It is just coincident that moon orbit on the ecliptics not on the equator and inclined at an angle of 5.145º to the ecliptic. Ascending and descending moon has two nodes. When Moon passes upward through the ecliptic ascending node is there and when passes downward descending node is there.

It Non-coincidence that the Earth's equatorial plane is with the ecliptic. The Earth's orbital plane is called its ecliptic The Earth equatorial plane is inclined at approximately 23.4^o to the plane of the Ecliptic.

Hope it does helps!!