Important Questions Test: Motions Of The Earth - UPSC MCQ

A leap year, where an extra day is added to the end of February every four years, is down to the Gregorian calendar's disparity with the solar system. A complete orbit of the earth around the sun takes exactly 365.2422 days to complete, but the Gregorian calendar uses 365 days.

The days are longer around the summer solstice and shorter around the winter solstice. When the Sun's path crosses the equator, the length of the nights at latitudes +L° and -L° are of equal length. This is known as an equinox. There are two solstices and two equinoxes in a tropical year.

Dawn is the time just before sunrise. During this time, the sky starts getting filled with the Sun's glow and the rays of the Sun start piercing the darkness.

Revolution is the term used to describe the path (or orbit) of Earth through space. Earth's revolution around the sun is responsible for seasonal change and leap years. This path is shaped like an ellipse and has points when Earth is closer to the sun and farther from it.

- The sun's rays are vertical over the Tropic of Capricorn during the summer solstice in the Southern Hemisphere, which occurs around December 21st.
- This event marks the longest day of the year for the Southern Hemisphere.
- At this time, the South Pole is tilted closest to the sun, resulting in direct sunlight over the Tropic of Capricorn, located at 23.5° south latitude.
- This phenomenon is essential for understanding Earth's tilt and its impact on seasonal changes.

sun provides heat so the area near the sun gets summer ant area away gets winter so, when the part of the earth where it was winter faces the sun ( revolving of earth) it is summer in that region and it is winter on the other region

we mean the time when the Sun passes the celestial meridian, reaching its maximum height in the sky. As the Earth turns on its rotation axis, it also moves along its orbit around the Sun. ... The speed chosen is the average speed of the Sun's ecliptic motion, leading to a mean solar day of 24 hours.

Winter, Autumn and Spring are names of seasons whereas, Axis is an imaginary line which runs through the poles on which the Earth rotates. 

Rotation and Revolution are two motions of the earth. When earth spins or rotates around its axis, that movement of spinning is called Rotation of Earth. And when earth spins or revolves around the sun, that movement is called Revolution of Earth.

The rotation of the earth on its own axis and the revolution of earth around the sun cause changes in season and day and night. The change in seasons is caused by the rotational tilt of the earth on its axis when it revolves around the sun.

The earth has an axial tilt of 23.5 degrees which means that its rotation axis is inclined to its orbital axis at an angle of 23.5 degrees. This causes one pole of the earth to be directed more towards the Sun on one side of the orbit, and the other pole on the other side. This is the reason for occurrence of 'seasons' on earth'.

As the earth spins on its axis, producing night and day, it also moves about the sun in an elliptical (elongated circle) orbit that requires about 365 1/4 days to complete. The earth's spin axis is tilted with respect to its orbital plane. This is what causes the seasons.

The imaginary line which divides the parts of the earth with day and night is called the circle of illumination. The circle of illumination is at right angle to the orbital plane. Thus, the circle of illumination is at an angle of 23.5 degree to the earth's axis.

The axis of the earth which is an imaginary line, makes an angle of  66^1/2° with its orbital plane. The plane formed by the orbit is known as the orbital plane. Theearth receives light from the sun.

The portion facing the sun experiences day while the other half away from the sun experiences night. The circle that divides the day from night on the globe is called the circle of illumination. The earth takes about 24 hours to complete one rotation around its axis.

This spinning movement is called Earth's rotation. At the same time that the Earth spins on its axis, it also orbits, or revolves around the Sun. This movement is called revolution.

In the winter, Earth tilts away from the Sun. In North America, around June 21, Earth tilts on its axis toward the Sun. This is called the summer solstice, and it is when the Northern Hemisphere has the most daylight of any time of the year.

The Poles basically experience about six months of day and six months of the night because of the tilt of the Earth on its axis. At the point when the North Pole is tilted towards the Sun, it experiences continuous daylight for six months.

Rotation is the movement of the earth on its axis.

The sun is exactly over the Tropic of Cancer. on 21st June summer solstice occurs in the northern hemisphere. It gets more heat and light and that time there is winter solstice in the Southern Hemisphere as it is away from the sun.

Earth's orbit is not a perfect circle. It is elliptical, or slightly oval-shaped. This means there is one point in the orbit where Earth is closest to the Sun, and another where Earth is farthest from the Sun.

 In Australia, Christmas is celebrated in the summer season. This is because of the tilt of the earth. Australia is situated in the southern hemisphere and during the month of December, there will be the summer season in the southern hemisphere and the winter season in the northern hemisphere.