- The earth rotates on its axis at an inclination of 23.5 relative to our orbital plane.
- The planets are kept in motion in their respective orbits by ‘Gravitation’ and ‘Centrifugal force’.
- Sun rises in the east and sets in the west due to the rotation of the earth on its axis.
- The distance between the Earth and the Sun in an Astronomical Unit (AU).
- The universe is filled with galaxies. Spiral and elliptical are the two shapes of galaxies.
- The color of the most of the stars in elliptical galaxies is ‘Red’ and the most of the stars in spiral galaxies is ‘Blue’.
- Stars in spiral galaxies are young and elliptical galaxies are older than spiral galaxies.
- There are estimated 100-400 billion stars in our Galaxy (The Milky Way).
- In the observable universe there are estimated 2 trillion galaxies.
- The Milky Way extends through a distance of light years.