September 16th should become some kind of comic national holiday because it’s the birthday of both Mike Mignola and Kurt Busiek, and as far as making quality comics goes, that is one heck of a dynamic duo. Today is Busiek’s 55th birthday, and this month marks the 20th anniversary of Busiek’s ongoing masterpiece with Alex Ross and Brent AndersonAstro City.

Over the course of the last two decades (and at four different publishers/imprints no less), Astro City has continued to show a different side of superhero comics and explore a world where heroes, villains, and the everyday people that crane their necks to the sky to behold them can feel larger than life or as real as someone sitting next to you.

One of the key factors in establishing this grandeur and groundedness of Astro City and its cast has always been the covers by artist Alex Ross. After working together on Marvels, Busiek brought Ross along to Astro City to design characters and provide the covers that would prove to be so striking and memorable.

In celebration of both Busiek and Astro City, we’ve compiled a collection of some of Ross’ best covers to showcase how the world of Astro City has changed over the years.