Question

robert is looking at four galaxies: an irregular galaxy the he calls \calliope\; a spiral galaxy that he calls \medea\; an elliptical galaxy that he calls \minerva\; and a lenticular galaxy that he calls \ariadne\; which of these four is the youngest? medea ariadne minerva calliope

Explanation:

Irregular galaxies are often considered the youngest type among common galaxy classifications. They lack a distinct regular shape and are thought to be in earlier stages of development compared to spiral, elliptical, and lenticular galaxies. Calliope is an irregular galaxy.

Answer:

Calliope