We live in a spiral galaxy called the Milky Way and can see many other spiral galaxies in the Universe. But how they form their spiral arms and how they last has been a significant question.
New research which included supercomputing simulations has provided some interesting results and a cool video on YouTube.
Read the results here http://www.news.wisc.edu/21636 before tuning in to YouTube here https://www.youtube.com/watch?v=5sGKuoBnTn0
By the way, the summer constellations that feature views of our galaxy are visible in the hours before dawn. But their true magnificence will have to wait until the hot nights of summer when fireflies keep earthly company with August thunderstorms and the Milky Way sweeping through Sagittarius into the Sumer Triangle.
Sky Guy in VA