Earth’s Axis
It is really surprising why earth is tilted on its own axis. Before discussing the reason we must know what axial tilt is. It happens when a planet is tilted a certain degree towards the ecliptic of the object it orbits on its vertical axis.
Scientists developed a theory which explains this position of earth. To know the answer we need to go back to the history of our solar system. Though we don't know exactly what happened in the past, but theoretically we can assume what happened in the beginning of our solar system. When our solar system gave birth to the Sun, a new source of gravity was created, the sun's gravity. The Sun's tidal forces helped in the formation of the planets. The dust, gases left in the nebula collided together and formed the planets.
At the beginning small versions of planets were formed which are proto-planets and planetesimals. These pre-planets have their own mass and gravity and the collidation of these pre-planets gave birth to new Planets. This process took millions of years to form the planets.
About earth's tilted position, scientists think that at the very last moment of earth's formation it was hitted by another proto-planet and collided with each other and in that process earth is tilted on its axis and lean at 23.44° towards the Sun. The exact tilted angle is 23.439281°.
Another theory about earth tilted connects to the weight or mass distribution over the planet. The Northern Hemisphere is covered with ice sheets which makes the earth top heavy which could be the reason for earth tilted position. It is similar if a spinning ball is top heavy then the ball will tilt a little bit during spinning.
HOW IMPORTANT IT IS?
Earth’s tilt is very important. Earth tilted position decides how much sunlight reaches the earth's surface during different seasons. Due to this position we can see seasons on earth which is another important factor to calibrate life. This position not only allows seasons but also a well balanced temperature on the planet. If planet earth was perfectly straight on its vertical axis then the day side will be too hot and the other side will be too cold.
HOW IT WORKS?
The North pole and South pole basically experience two seasons: the summer and the winter. When the North pole faces the Sun then it experiences summer and the south pole faces winter. In about six months this situation will be reversed, where the south pole experiences summer and north pole experiences winter. These two seasons continue for six months. The summer six months there is constant daylight and winter six months constant night.
In the rest of the planet's surface four seasons can be identified by the solstices and equinoxes. Winter starts around 21st December and lasts till February, Spring starts on Marth and ends in May, Summer starts in June and lasts till August, Autumn starts in September and ends in November.
During winter night stays long and shorter daylight and weather stays cold, Spring is neither cold nor hot, a well balanced weather, in the Summer daylight lasts longer and weather stays hot and Autumn weather turns rainy and moisture in the air feels you hot and due to the rain sometimes feels you cold.
This tilted position also affects the sun's rising direction. In the Northern Hemisphere, during summer the Sun rises from the north-east and sets on the north-west. On the other side in the south pole Sun rises from the south east and sets on the south-west.
Know More About The Sun
