Explain why astronomers use the term "blueshifted" for objects moving toward us and "redshifted" for objects moving away from us.

Two of them are "redshift" and "blueshift", which are used to describe an object'smotion toward or away from us in space. Redshift indicates that an object is moving away from us. "Blueshift" is a term that astronomers use to describe an object that is moving toward another object or toward us.