NASA and ESA celebrated the 20th anniversary of the installation of the Hubble Space Telescope’s ACS (Advanced Camera for Surveys) instrument with the publication of some images among the more than 125,000 captured during these twenty years of service. On March 7, 2002, astronauts James Newman and Mike Massimino installed the ACS during the space shuttle Columbia’s STS-109 mission. This instrument made a significant contribution to a lot of extraordinary astronomical research conducted using Hubble.