If a star is moving towards the earth, then the lines are shifted towards

If the star approaches the earth. The Doppler lines are shifted

The force of attraction of the earth on an apple is of the same magnitude as the force of attraction of the apple on the earth, yet the apple moves towards the earth, but the earth does not move towards the apple. Why?

A star is moving towards the earth with a speed of 9 xx 10^(6) m//s . If the wavelength of a particular spectral line emitted by star is 600 nm , find the apparent wavelength.

A star is moving towards the earth with a speed of 4 xx 10^(7) m//s . If the wavelength emitted by the star is 500 nm , what would be the change in wavelength received on earth ?

If the moon attracts the earth, why does the earth not move towards the moon?

If the moon attracts the earth, why does the earth not move towards the moon ?

If the moon attracts the earth, why does the earth not move towards the moon?