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Earth (Prithvi) is the only planet where life is known to exist. Earth has only one natural satellite, called Moon. Some environmental conditions are mainly responsible for the existence of life on Earth.
 
earth.jpg
Earth
 
Conditions responsible for life on Earth:
  • The right distance from the Sun,
  • Right temperature range,
  • Presence of water,
  • Suitable atmosphere, and
  • A blanket of ozone.
space-outer-space-photography-of-earth-earth-earth-image.jpg
Earth's atmosphere
 
Appearance:
The Earth appears blue and green from space. This appearance is due to the reflection of light from the water and the landmass on the Earth surface.
 
Axis of the Earth:
The Earth's axis is tilted to a side by 23.5\ degrees, and it is not perpendicular to the plane of its orbit. This tilted axis is responsible for the cycle of seasonal changes on Earth.

changed season.png
Position of Earth around the Sun
 
Rotation of Earth on a tilted axis:
The Equatorial plane is the plane of the equator, and the orbital plane is the plane in which the Earth revolves around the Sun.
The equatorial plane is inclined to the orbital plane at an angle of 23.5\ degrees. Thus, the Earth's axis is inclined to its orbital plane at an angle of 66.5\ degrees.
 
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Earth's equatorial and orbital plane
 
Earth completes its rotation from west to east in 24\ hours, and the period of revolution is 365.25\ days.
 
Important!
Fun fact
A person at the age of 20 years would have gone around the Sun 20 times.
Reference:
https://cdn1.photostockeditor.com/c/1904/space-outer-space-photography-of-earth-earth-earth-image.jpg
https://live.staticflickr.com/65535/48322498346_e743933560_b.jpg