Mercury, 'fast' stars Arcturus & Altair, and more in Sept. 2021 skywatching

Mercury is viewable briefly at sunset in the west. "Speedy Arcturus and fast-spinning Altair," are great skywatching targets as well in Sept. 2021, according to NASA's Jet Propulsion Laboratory. Night sky: What you can see this month: https://www.space.com/16149-night-sky.html

Best night sky events this month - stargazing maps: https://www.space.com/33974-best-night-sky-events.html

Credit: NASA's Jet Propulsion Laboratory