Why does the Sun rise in the east and set in the west on the Earth? Does the concept hold equally good for all the planets in the Solar System?
The Earth spins on its axis from west to east. Hence the sky appears to move from east to west. In the case of the other planets, the Sun will rise in the east to west. In the case of the other planets, the Sun will rise in the east and set in the west, when viewed from the surface of that particular planet, only if that planet is spinning in the same direction as Earth, with respect to the Sun. In all the planets the Sun rises in the east and sets in the west. In the case of Venus, Uranus and Pluto, the Sun rises in the west and sets in the east, since the planets spin in the west and sets in the east, since the planets spin in the opposite direction.
Are all planets oblate spheroids?
All the planets exhibit oblate spheroidness to some degree, the extent of which increases with increasing speed of spinning and decreases with increasing density. Consequently, a gaseous planet with a rapid axial rotation like Saturn exhibits a very high degree of oblate spheroidness. For example, Jupiter whose day is less than 10 hours has its diameter over 140,000 km at the Equator and less than 133,000 km at the poles.