The Simons Observatory will provide scientists an unprecedented glimpse into the nature of fundamental physical processes that have governed the origin and evolution of the universe since the dawn of time itself. The project consists of the existing Atacama Cosmology Telescope (ACT), The Simons Array, and 4 new instruments: 3 half-meter, Small Aperture Telescopes (SATs), and 1, 6 meter, Large Aperture Telescope (LAT). Over 270 scientists, engineers and technologists form over 35 institutions around the world are contributing to the project, making it the world’s largest cosmology collaboration.
Simons Observatory site aerial view Simons Array Polar Bear Telescope Simons Observatory, Atacama, Chile Ground breaking for the Simons Observatory
The Observatory is being built at an altitude of 17,000 ft on Cerro Toco mountain, in the Atacama desert region in Chile. One of the driest, most rugged places on earth. SO will measure the temperature and polarization anisotropy of the cosmic microwave background in six frequency bands centered at: 27, 39, 93, 145, 225 and 280 GHz.


Using an array of four telescopes, the Simons Observatory will have 60,000 detectors on-sky, more than all other CMB experiments combined. At an operating temperature of 0.1 kelvin, SO’s superconducting detectors have excellent precision and resolution at extremely low noise levels. The Simons Observatory will begin a 5 year observing campaign in late 2022.