"Many people say, 'I don't know what star clusters are going to look like,'" Seth said. "But once you get started, you start seeing a pattern of clusters among individual stars."
Participants will also see distant galaxies in the background, notable for their spiral shapes and dimmer light.
Stars can appear blue, white or reddish. Seth said that clusters with a lot of blue stars are younger in age, while white or reddish stars are older.
The clusters are thought to form from dense clouds of gas that collapse inward owing to the force of gravity before breaking up into distinct stars.
"The details of how that happens is not well understood," Seth said.
It wasn't until the 1920s that astronomer Edwin Hubble confirmed other galaxies exist beyond the Milky Way, each with billions of stars. Hubble observed Andromeda. It isn't the closest galaxy, but Andromeda is the Milky Way's closest spiral-shaped neighbor.
Andromeda wraps hundreds of billions of stars in a diameter spanning 160,000 light years across — that's 940 million-billion miles, astronomers say. The star clusters in Andromeda are typically about 20 light years across, or 118 trillion miles.