When you think of a galaxy, you likely think of a spiral galaxy. More specifically, you likely imagine a spiral galaxy with two large sweeping arms of stars, such as the image of the Whirlpool Galaxy above. Such a galaxy is known as a grand design spiral, and while it’s an iconic style, it isn’t particularly common among galaxies.
Riding the Wave
Just how do spiral galaxies form? It’s all due to a stellar traffic jam, and now the process has been observed in our own galaxy.
Traffic Jam
How do spiral galaxies maintain their spiral shapes? It turns out there are matter waves that cause traffic jams within the spirals. These patterns are stable even as individual stars move through them.