Test: Motions Of The Earth - UPSC MCQ

Earth takes 365 days and 6 hours to complete a revolution around the sun .That's why leap year takes place as after four years 6 hrs each year becomes a total of 24 hrs making the 366 days of the leap year.

The summer solstice , also known as midsummer, occurs when a planet's rotational axis, or geographical pole on either its Northern or its Southern Hemisphere is most greatly inclined toward the star that it orbits. On the summer solstice, Earth's maximum axial tilt toward the Sun is 23.44degree. (the Sun's declination from the celestial equator is 23.44degree.) This happens twice each year (once in each hemisphere), when the Sun reaches its highest position in the sky as seen from the North or South Pole

Equinoxes happen two times in a year when day and night are of equal length. In the Earth's Northern Hemisphere, for example, the vernal equinox cues the beginning of spring around March 21 and the autumnal equinox indicates the beginning of fall around September 23.

Earth travels in an elliptical, or oval-shaped, orbit around the sun. As a result, the distance between Earth and the sun varies by about 3% throughout the year.

On June 21 the Sun’s rays fall vertically on the tropic of Cancer. They usually fall on one spot somewhere, once a year, for a moment. The tropic of Cancer is a line which is located between the Arctic Circle and the Equator and describes how far from north you can be and you can still have the sun at your zenith during the summer season in the northern hemisphere.

This is incorrect because, if the Earth did not rotate, half of the Earth would experience continuous daylight, and the other half would be in continuous darkness. There would be no alternation of day and night on either side, so no part of the Earth would experience a regular cycle of day and night.

• The angle of inclination of the earth's axis with its orbital plane is 23.5 degrees. This tilt is the reason we experience different seasons throughout the year.
• Imagine the Earth leaning just a little bit as it goes around the Sun, causing summer, winter, spring, and autumn to happen at different times of the year.

In a leap year, there are 366 days. This extra day is added to February to keep our calendars accurate. So, a leap year has one extra day compared to a regular year.