CBSE Class 6 Answered
A solstice is a day, when the Sun shines vertically over a Tropic (Cancer or Capricorn) in the afternoon, and the day is longest in that hemisphere. The Southern Hemisphere faces the Sun from 21 June to 22 December. During this time it experiences summers. On 22 December, the rays of the Sun fall directly over the Tropic of Capricorn. This is the longest day in the Southern Hemisphere (as it is the summer season) while in the Northern Hemisphere, it is the shortest day (as it is winter season). This is known as the winter solstice. On 21 June, sunlight falls vertically over the Tropic of Cancer. This is the longest day in the Northern Hemisphere and hence it is known as the summer solstice.
On 21 March and 21 September, the Sun’s rays fall directly over the equator. On both these days, the lengths of day and night are equal on all places on the Earth’s surface. This is called equinox. This occurs as neither of the two poles is tilted towards the Sun. On 21 March, it is autumn in the Southern Hemisphere and spring in the Northern Hemisphere. On 23 September, it is autumn in the Northern Hemisphere and spring in the Southern Hemisphere.