NGC 3521：气泡里的星系
2022年5月5日 NGC 3521: Galaxy in a Bubble Image Credit & Copyright: Mark Hanson and Mike Selby Explanation: Gorgeous spiral galaxy NGC 3521 is a mere 35 million light-years away, toward the northern springtime constellation Leo. Relatively bright in planet Earth’s sky, NGC 3521 is easily visible in small telescopes but often overlooked by amateur ima...