7 March 2022 marks the 20th anniversary of the Advanced Camera for Surveys (ACS) aboard the NASA/ESA Hubble Space Telescope. On 7 March 2002 astronauts installed the ACS during Hubble Servicing Mission 3B, also known as STS-109. With its wide field of view, sharp image quality, and high sensitivity, the ACS delivers many of Hubble’s most impressive images of deep space.
The ACS wavelength range extends from the ultraviolet, through the visible and out to the near-infrared. Its name, the Advanced Camera for Surveys, comes from its particular ability to map large areas of the sky in great detail. The ACS can also perform spectroscopy with a special optical tool called a grism.
Three subinstruments make up the ACS. The Wide Field Channel is a high-efficiency, wide-field, optical and near-infrared camera that is optimised to hunt for galaxies and galaxy clusters in the remote and ancient Universe, at a time when the cosmos was very young. The High Resolution Channel was designed to take extremely detailed (high resolution) pictures of the light from the centres of galaxies with massive black holes, though this is not currently operational, and the Solar Blind Channel blocks visible light to allow faint ultraviolet radiation to be discerned. Amongst other things, it can be used to study weather patterns on other planets and aurorae on Jupiter.