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South Pole Telescope

A man in winter gear stands in front of a large dish with a background of snow and blue sky.
NIST’s Hannes Hubmayr at the South Pole Telescope
Credit: NIST

Telescope Details



Amundsen-Scott South Pole Station, Antarctica


With a 10-meter primary mirror, the South Pole Telescope is the largest millimeter-wave telescope dedicated to observing the cosmic microwave background (CMB) and can produce large-scale CMB maps at unparalleled resolution. 

NIST’s role:

NIST has played a significant role in all three generations of SPT cameras, providing sensors and/or electronics to collect sensor data for SPT-SZ, SPTpol, and the current camera, SPT-3G. 

Significant discoveries:

The SPT made the first detection of the B-mode lensing signal, which results when the gravity of massive objects distorts polarized light from the CMB before it reaches Earth. B-mode lensing provides information on the growth rate of large structures in the cosmos. It can also constrain the sum of masses for the different types of neutrinos. This quantity is currently unknown.

Other interesting facts:

With its unique location, the SPT plays a critical role in achieving the goal of the Event Horizon Telescope network to image the event horizon around the black hole at the center of our galaxy.

Supported by:

National Science Foundation, DOE Office of Science High Energy Physics, Kavli Institute for Cosmological Physics, U.S. Antarctic Program and Antarctic Support Contract


Circular gold-colored plate has seven smaller circles in the center.
South Pole telescope sensor array
Credit: NIST
Created October 7, 2021, Updated May 15, 2024