The speed of recession of a galaxy is proportional to its distance.

The hottest planet of the solar system is

The tail of the comet is due to

Which one of the following planets has the longest day?

If a galaxy is at a distance of $430$ million light years from us,what is the Hubble's constant in $km s^{-1}$ per million light years? Its speed is $6.48 \times 10^6 m s^{-1}$.

The angle of maximum elongation for Venus is $47^\circ$. The distance of Venus from the Sun in $AU$ is .......