Local Group of Galaxies

Local Group of Galaxies

Several million light-years across, the Local Group of galaxies is composed of some twenty constituent galaxies. It is a sparse and obscure and unpretentious cluster. One of the galaxies is M31, seen from the Earth in the constellation Andromeda. Like other spiral galaxies, it is a huge pinwheel of stars, dust and gas. M31 has two small satellites, dwarf elliptical galaxies bound to it by gravity, by the identical law of physics that tends to keep us in our chairs. The laws of nature are the same throughout the Cosmos, even if we are two million light-years from home.

Beyond M31 is another, very similar galaxy, our own, its spiral arms turning slowly, once every quarter billion years.

We, the Earthlings, live in the remote outskirts of the Galaxy, in an obscure locale near the edge of a distant spiral arm. And we find ourselves falling toward the massive center of the Milky Way.

Cluster of Hercules. Local group of galaxies © Megan Jorgensen (Elena)