M66, also known as NGC 3627, is a spiral galaxy located approximately 35 million light-years away in the constellation Leo. It is part of the Leo I Group of galaxies and is characterized by its bright core and prominent spiral arms, which contain numerous stars and nebulae. Discovered by the astronomer William Herschel in 1780, M66 has a diameter of about 95,000 light-years. It is notable for its interactions with nearby galaxies, particularly M65 and NGC 3628, which can affect its structure and star formation activity. M66 is a popular target for amateur astronomers and astrophotographers.