- Why is HCRO here?
- Have you found anything yet?
- Do you send out any signals?
- How is this observatory funded?
- What's in the tent?
- When will the ATA be completed?
- How many are on staff?
- Is there a tour?
Questions about Radio Astronomy:
- What are radio waves?
- What's the difference between Sound Waves and Radio Waves?
- What can Radio waves tell us about the universe?
- What produces radio emission from space?
- What are some famous discoveries made at HCRO?
- What advantages does the ATA present to scientific study?
- What is SETI?
- How does the SETI search work?
- What is the ATA's role in SETI?
- How do you know if you've detected an intelligent signal?
- Why do you think E.T. will broadcast in the microwave frequency band?
- What happens if you detect a signal?
- Why is HCRO here?
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.
- Have you found anything yet?
Some of the more famous discoveries at HCRO 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. Rest assured, if we detected an intelligent signal from space, you won't have to drive to HCRO to know about it.
- Do you send out any signals?
No. The telescopes are equipped only to receive, not transmit.
- How is this observatory funded?
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.
- What's in the tent?
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.
- When will the ATA be completed?
The first phase of construction is for a 42 element array. The ATA-42 is scheduled for completion in the fall of 2006. The entire 350 element array is scheduled for completion in the summer of 2008.
- How many are on staff?
We currently have nine permanent staff. The total number of staff on site varies.
- Is there a tour?
Walk-in tours are usually available in the summer during our business hours (9am to 3pm). You may view a short video on HCRO inside if no one is available to show you around. Groups of ten or more are encouraged to schedule thier tour in advance. Our telephone number is 530.335.2364.
Questions about Radio Astronomy:
- What are radio waves?
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.
- What's the difference between Sound Waves and Radio Waves?
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.
- What can Radio waves tell us about the universe?
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.
- What produces radio emission from space?
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.
- What are some famous discoveries made at HCRO?
What are some famous discoveries made at HCRO? In 1968 Berkeley astrophysicists Jack Welch and Charles Townes used a 10-ft telescope (which can still be seen off of Bidwell road leading into the observatory) 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.
- What advantages does the ATA present to scientific study?
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.
- What is SETI?
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.
- How does the SETI search work?
The Targeted Search System looks for signals in the range 1,000 MHz to 3,000 MHz, with a frequency resolution of 1 Hz. The ability to detect slowly-drifting signals and the application of near real-time data processing make this search the most comprehensive and sensitive SETI search in the world today.
- What is the ATA's role in SETI?
The ATA will be the world's first radio telescope dedicated to the SETI search. The ATA is almost 1,000 times faster than the Arecibo telescope, between 20 and 2000 times faster than the Very Large Array (depending on the scientific program) and 50 times faster than the Green Bank Telescope. The ATA will be the fastest Radio telescope in the world making it perfect for doing surveys. In addition to the SETI search, the ATA will be surveying transient radio sources, galactic hydrogen, and pulsars.
- How do you know if you've detected an intelligent signal?
The main feature distinguishing signals produced by a transmitter from those produced by natural processes is their spectral width (i.e. how much room on the radio dial do they take up). Any signal less than about 300 Hz wide must be, as far as we know, artificially produced. Such narrow-band signals are what all SETI experiments look for. Other tell-tale characteristics include a signal that is completely polarized or the existence of coded information on the signal. Unfortunately, SETI searches are burdened with confusion caused by narrow-band signals from our own planet. Military radar and telecommunications satellites produce such signals.
- Why do you think E.T. will broadcast in the microwave frequency band?
There is relatively little background static from galaxies, quasars, and other cosmic noisemakers in the microwave part of the spectrum. This makes faint signals easier to pick out. Additionally, the microwave band contains a naturally-produced emission line, a narrow-band "broadcast", at 1,420 MHz due to interstellar hydrogen. Every radio astronomer (including extraterrestrial ones) will know about this hydrogen emission. It may serve as a universal "marker" on the radio dial. Consequently, it makes sense to use nearby frequencies for interstellar "hailing" signals.
- What happens if you detect a signal?
The first thing to do is to confirm that it's truly extraterrestrial. Remember, with tens of millions of channels and antennas that are among the world's largest, SETI picks up signals frequently. An important test to verify that a signal is truly extraterrestrial would be a confirming observation at another radio telescope. Once an artificial signal is confirmed as being of extraterrestrial intelligent origin, the discovery will be announced as quickly and as widely as possible. A Declaration of Principles Concerning Activities Following the Detection of Extraterrestrial Intelligence, endorsed by six international space organizations, describes how to make such an announcement. The SETI Institute has a plan of action that resembles the Declaration of Principles. There will be no secrecy, and indeed getting the word out quickly is important, as there would be an urgent need to have astronomers world-wide monitor any detected signal, 24 hours a day.
Original FAQ by Sanj Brar. Updated and Edited by Rick Forster and Brian Kearney. Visual and layout redesign by Colby Gutierrez-Kraybill