Allen Telescope Array

The Allen Telescope Array is a radio telescope facility comprising 42 antennas arranged across the Hat Creek Radio Observatory grounds in northern California. The antennas work together to capture and analyze faint signals traveling through space.

Construction of the array began in 2001 with funding from a private foundation, and first observations began in 2007. This marked the start of a new era in radio astronomy at the facility.

The facility serves as a hub for radio astronomers dedicated to studying the cosmos and searching for signals from space. It represents humanity's ongoing effort to understand what lies beyond our world.

The facility sits on elevated terrain near Hat Creek and is reachable by road with a designated visitor parking area. Visitors should know this is an active research center, so access and close approach are restricted.

Each antenna uses a specialized mirror design that filters out ground-based interference while allowing clear signals from space to come through. This technical feature makes the antennas especially sensitive to faint cosmic signals.

Location: California

Diameter: 2.4 m

Part of: Hat Creek Radio Observatory

Website: http://seti.org/ata

GPS coordinates: 40.81778,-121.47333

Latest update: December 7, 2025 09:21