The Sun rises in the east (far arrow), culminates in the south (to the right) while moving to the right, and sets in the west (near arrow). Both rise and set positions are displaced towards the north in midsummer and the south in midwinter. In the Southern Hemisphere, south is to the left.
Yes, the Sun - in fact, our whole solar system - orbits around the center of the Milky Way Galaxy. We are moving at an average velocity of 828,000 km/hr. But even at that high rate, it still takes us about 230 million years to make one complete orbit around the Milky Way!
Earth has seasons because its axis is tilted. Earth's axis is always pointed in the same direction, so different parts of Earth get the Sun's direct rays throughout the year. For example, in summer, the Sun's rays hit that region more directly than at any other time of the year.
On other days, the Sun rises either north or south of "due east" and sets north or south of "due west." Each day the rising and setting points change slightly. At the summer solstice, the Sun rises as far to the northeast as it ever does, and sets as far to the northwest.
Usually when most of us say noon, we mean 12 p.m. on the clock. The time at which the sun crosses the meridian used to be called high noon because that is when the sun is highest in the sky. Today we astronomers sometimes refer to it as transit time or local solar noon.
Scientists estimate that Earth suffered around 10 of these giant collisions. Today, instead of rotating upright, the Earth's axis is tilted 23.5 degrees. The angle varies a little over time, but the gravitational pull of the moon prevents it from shifting by more than a degree or so. This tilt is what gives us seasons.
It is all about the tilt of the Earth's axis. Many people believe that the temperature changes because the Earth is closer to the sun in summer and farther from the sun in winter. In fact, the Earth is farthest from the sun in July and is closest to the sun in January! Thus, we have winter!
Here is a guide tour to the 6 seasons of India as per the Hindu Calendar
- Spring (Vasant Ritu)
- Summer (Grishma Ritu)
- Monsoon (Varsha Ritu)
- Autumn (Sharad Ritu)
- Pre-winter (Hemant Ritu)
- Winter (Shishir or Shita Ritu)
The Moon's InfluenceThe Earth's axis is tilted at 23.5 degrees from the ecliptic. That angle is responsible for the seasons. The moon's gravitational pull on the Earth causes precession -- a small, 21,000-year cyclic change in the angle of the Earth's tilt.
Winter is caused by the axis of the Earth in that hemisphere being oriented away from the Sun. When it is winter in the Northern Hemisphere, it is summer in the Southern Hemisphere, and vice versa. In many regions, winter is associated with snow and freezing temperatures.
We are not getting closer to the sun, but scientists have shown that the distance between the sun and the Earth is changing. The sun's weaker gravity as it loses mass causes the Earth to slowly move away from it. The movement away from the sun is microscopic (about 15 cm each year).
On Friday, June 21, the sun brightens our skies longer than on any other day in 2019. The summer solstice is here: our longest day and shortest night of the year, and the first day of astronomical summer in Earth's Northern Hemisphere.
Its rotation direction is prograde, or west to east, which appears counterclockwise when viewed from above the North Pole, and it is common to all the planets in our solar system except Venus and Uranus, according to NASA.
The earth's spin axis is tilted with respect to its orbital plane. This is what causes the seasons. When the earth's axis points towards the sun, it is summer for that hemisphere. Midway between these two times, in spring and autumn, the spin axis of the earth points 90 degrees away from the sun.
Instead, the seasons are caused by the 23.5° tilt of Earth's axis of rotation relative to its plane of orbit around the Sun (Figure below). In the Southern Hemisphere, the Sun is as far away as it will be and so it is their winter. Locations will have longer nights and shorter days.
So, in the Northern Hemisphere you have:
- Vernal equinox(about March 21): day and night of equal length, marking the start of spring.
- Summer solstice (June 20 or 21): longest day of the year, marking the start of summer.
- Autumnal equinox(about September 23): day and night of equal length, marking the start of autumn.
The first major contributor to the Sun's apparent motion is the fact that Earth orbits the Sun while tilted on its axis. The Earth's axial tilt of approximately 23.5° ensures that observers at different locations will see the Sun reach higher-or-lower positions above the horizon throughout the year.
You may have noticed two special lines of latitude on a globe of the world: One in the Northern Hemisphere called the Tropic of Cancer at +23.5° latitude and one in the Southern Hemisphere called the Tropic of Capricorn at − 23.5° latitude. These are the latitudes where the Sun is directly overhead at noon once a year.
This apparent motion across the sky is due to the rotation of Earth. As Earth turns eastward on its axis, we move along with it, creating the illusion that the Sun moves through the sky over a day. At this time, the Sun appears to move in a high arc across the sky.
Answer. Answer: The Earth is at the winter solstice "20-22nd December".
The Earth's axial tilt moves the Sun north/south over the year, and the elliptical orbit moves it east/west. Combine the two, and you get that crazy figure-8 in the sky.
