This star-forming region is one of many in M33 that’s birthing new stars from massive clouds of dust and gas. (Credit: ESA/Hubble and NASA)

Astronomers have witnessed a rare event: the birth of massive stars 2.73 million light-years away in the Triangulum Galaxy (Messier 33). At the center of two giant colliding gas clouds are some 10 young stars with masses tens of times that of the Sun. Their discovery indicates that such cloud-cloud collisions are a main pathway to creating giant stars in