Questions about Radio Astronomy:
Hat Creek Radio Observatory (HCRO) is a research facility used to study radio emission from space. The observatory has been here nearly half a century (since 1959). Hat Creek Valley is an ideal site for radio astronomy because of its relatively low levels of man-made radio interference. The observatory is surrounded by volcanic mountains that keep out terrestrial radio interference like television, radio and cellular phone transmissions.
Some of the more famous discoveries at HCRO while under the operation of UC Berkeley Radio Astronomy Lab include the detection of amino acids in space and other exotic and complex molecules. One of the first complete maps of galactic hydrogen was made at HCRO using the 85 ft telescope. The observatory has also provided tremendous insights into the process of star formation by making high-resolution images of the molecular and ionized components of star-forming regions.
No. The telescopes are equipped only to receive, not transmit.
HCRO is operated as a partnership between the University of California Berkeley and the SETI Institute. The SETI Institute receives most of its funds from people like you. In 2003, the SETI Institute received a grant from the Paul G. Allen foundation for 25 million dollars to begin construction of the ATA. Some funding for radio astronomy equipment comes from the National Science Foundation and the State of California.
The tent is the assembly room for the dish, sub-reflectors, and alidades. The tent protects our technicians from the wind, which is essential for a safe welding environment and performing fine installation procedures.
In 2003, the SETI Institute received a grant from the Paul G. Allen foundation for 25 million dollars to construct the ATA (Allen Telescope Array). Additional funding for radio astronomy equipment came from the National Science Foundation and the State of California. The first phase of construction of the current 42 element array was completed in 2007. Final build-out will be a 350 element array.
We currently have four permanent staff. The total number of staff on site varies.
Self-guided tours are available during our business hours (9am to 3pm). You may view a short video on HCRO inside the main lobby. Groups of ten or more are encouraged to schedule their visit in advance. Our telephone number is 530.335.2364.
Questions about Radio Astronomy:
Radio, like optical light, is a band of wavelengths in the Electromagnetic Spectrum. The Electromagnetic Spectrum characterizes all light by its wavelength or frequency. Objects in the universe radiate electromagnetic waves in all the bands of the Electromagnetic Spectrum, not just optical light. Hence we have radio, IR, optical, UV, X-ray and gamma-ray telescopes in order to study the universe in all of its emissions.

Sound waves are planar waves of high and low pressure propagating outward from a source through a medium like air, water, basalt rock, or whatever. Electromagnetic waves differ in that they can travel in a vacuum and are composed of electric and magnetic fields, and they travel at the speed of light (a million times faster than the speed of sound through air). Radio stations use radio waves to carry audible information. The audio modulation on the radio "carrier" can be transformed back into a sound using a radio receiver and a speaker. While everyday experience and Hollywood movies make people think of sounds when they see the words "radio telescope," radio telescopes do not actually detect sound waves.
Radio waves can travel through interstellar dust and gas. This enables astronomers to see into dusty regions invisible to optical telescopes. Many molecules, including organic molecules, emit radio waves when they change energy level. For instance, Atomic Hydrogen, the most abundant material in space emits a radio wave with a wavelength of 21 cm when the spin of its electron flips over to reach a lower energy state. By tuning their instruments to the wavelength of atomic hydrogen, radio astronomers have inferred the earth's location within the Milky Way as well as our galaxy's motion and structure.
1. Thermal radiation from solid bodies such as the planets, ionized gas from stars, or dust in molecular clouds. 2. Synchrotron radiation from high-speed electrons traveling in magnetic fields. 3. Spectral line radiation from atomic and molecular gas in the interstellar medium or in the gaseous envelopes around stars. 4. Pulsed radiation resulting from the rapid rotation of neutron stars surrounded by an intense magnetic field and energetic electrons.
In 1968 Berkeley astrophysicists Jack Welch and Charles Townes used a 10-ft telescope to detect polyatomic molecules in the interstellar medium for the first time: ammonia (NH3) and water (H2O). In 1965, Harold Weaver, Nan Dieter, and David Williams discovered maser emission from OH molecules in our galaxy using the 85' telescope. A Maser is a naturally occurring Laser which emits at Microwave rather than Light wavelengths. These discoveries sparked further research into the physical description of the interstellar medium, resulting in the development of new and better radio telescopes.
The ATA has four primary advantages for scientific studies over all major radio telescopes built to date: a very wide field-of-view (2.45° at 21cm), complete instantaneous frequency coverage from 0.5 to 11.2 GHz, multiple simultaneous backends, and active interference mitigation. The instantaneous area of sky imaged is unprecedented in radio astronomy.
SETI is an acronym for the Search for ExtraTerrestrial Intelligence. The mission of the SETI Institute is to explore, understand, and explain the origin, nature, and prevalence of life in the universe. More information on SETI and the ATA can be obtained at the SETI Web page.
Original FAQ by Sanj Brar. Updated and Edited by Rick Forster and Brian Kearney. Visual and layout redesign by Colby Gutierrez-Kraybill. Subsequent editing by Elin Klaseen