Physics – 6.2.3 The Universe | e-Consult

The diameter of the Milky Way being approximately 100,000 light-years indicates the vast scale of the galaxy. A light-year is the distance light travels in one year. Therefore, a diameter of 100,000 light-years means that the distance across the Milky Way is equivalent to 100,000 times the distance light travels in a year. This implies that the distances between stars within the Milky Way are immense. Stars are incredibly far apart, even within our own galaxy. For example, the distance between our Sun and the nearest star is about 4.2 light-years. This demonstrates the huge scale of the Milky Way and the distances involved in interstellar space. The vastness of the galaxy makes interstellar travel extremely challenging.