Stars that are moving away from Earth _____. look red have spectra that are red-shifted look blue have spectra that are blue shifted
Stars that are moving away from Earth have spectra that are red shifted. The correct answer among all the answers that are given in the question is the second option. This also called the Doppler Effect. when stars are moving towards the earth, then they will have a blue shifted spectra and when stars are moving away from the earth they will have a spectra that is red shifted.