Space is big, so why not travel across the cosmos with friends? This image from the Gemini observatory in Hawaii shows a galactic herd called VV 166, which lies about 300 million light-years away. Similar galaxy groups exist across the universe—our own Milky Way is part of a "local group" that includes the Andromeda galaxy, the Triangulum galaxy and the Magellanic Clouds, among others.
This image of VV 166 clearly shows the diverse types of galaxies that can coexist in such groups. The prominent spiral galaxy NGC 70, near the top of the image, glows blue with new star formation in its shapely arms. By contrast, the two small galaxies below the spiral look wan and pale, showing signs that they are no longer giving birth to many new stars. The one to the left, NGC 71, is actually a strange beast called a lenticular galaxy, a lens-shaped object that looks like a spiral galaxy that is missing the telltale arms. The one to the right is a much older elliptical galaxy called NGC 68, a proper blob of old stars. Such detailed portraits of galactic groups can help astronomers figure out how galaxies get their different shapes, and whether galaxies form together in groups or if they pick up new companions as they move through the universe.