Define briefly the following terms and mention the dates on which these are experienced:
(a) Solstice
(b) Equinox
(c) Aphelion (d) Perihelion.
Answers
Answer:
Explanation:
A solstice is an event occurring when the Sun appears to reach its most northerly or southerly excursion relative to the celestial equator on the celestial sphere. Two solstices occur annually, around June 21 and December 21. In many countries, the seasons of the year are determined by reference to the solstices and the equinoxes.
An equinox is commonly regarded as the instant of time when the plane (extended indefinitely in all directions) of Earth's equator passes through the geometric center of the Sun's disk.[3][4] This occurs twice each year, around 20 March and 23 September. In other words, it is the moment at which the center of the visible Sun is directly above the equator.
The Earth is closest to the Sun, or at the perihelion, about 2 weeks after the December Solstice, when it is winter in the Northern Hemisphere. Conversely, the Earth is farthest away from the Sun, at the aphelion point, 2 weeks after the June Solstice, when the Northern Hemisphere is enjoying warm summer months.