Editing Project Ozma

{{short description|1960 SETI experiment}}
[[File:Howard E. Tatel Radio Telescope - side.jpg|thumb|The {{Convert|85|ft|m|adj=on}} [[Green Bank Interferometer|Howard E. Tatel Radio Telescope]] at NRAO used in the project]]
'''Project Ozma''' was a [[search for extraterrestrial intelligence|search for extraterrestrial intelligence (SETI)]] experiment started in 1960 by [[Cornell University]] astronomer [[Frank Drake]], at the [[Green Bank Observatory|National Radio Astronomy Observatory, Green Bank]] at [[Green Bank, West Virginia]]. The object of the experiment was to search for signs of life in distant [[planetary system]]s through interstellar radio waves.  The program was named after [[Princess Ozma]], ruler of the fictional [[land of Oz]], inspired by [[L. Frank Baum]]'s supposed communication with Oz by radio to learn of the events in the books taking place after ''[[The Emerald City of Oz]]''.<ref name="SETI">{{Cite web |work=SETI Institute |title=Project Ozma |url=https://www.seti.org/seti-institute/project/details/early-seti-project-ozma-arecibo-message |first=Seth |last=Shostak}}</ref>  The search was publicized in articles in the popular media of the time, such as [[Time (magazine)|''Time'' magazine]] and was described as the first modern SETI experiment.<ref>{{Cite magazine |title=Science: Project Ozma |url=http://www.time.com/time/magazine/article/0,9171,874057,00.html |archiveurl=https://web.archive.org/web/20090911035633/http://www.time.com/time/magazine/article/0,9171,874057,00.html |archivedate=2009-09-11 |magazine=Time |date=April 18, 1960}}</ref>

Drake used a radio telescope with a diameter of {{convert|85|ft|m|sp=us}} to examine the stars [[Tau Ceti]] and [[Epsilon Eridani]] near the 1,420 MHz marker frequency, the equivalent of wavelength of [[Hydrogen line|21 centimeters]] which corresponds to the energy of a photon emitted from a hydrogen atom during "spin-flip" transition.<ref name="SETI" /><ref>{{cite news |last1=Arthur |first1=Charles |title=Science: The Truth About... Extraterrestrials and the 'Hydrogen Band' |url=https://www.independent.co.uk/arts-entertainment/science-the-truth-about-extraterrestrials-and-the-hydrogen-band-1198826.html |access-date=2 January 2021 |work=The Independent |date=17 September 1998 |language=en}}</ref> Both are nearby Sun-like stars that then seemed reasonably likely to have inhabited planets.  A 400 kilohertz band was scanned around the marker frequency, using a single-channel receiver with a bandwidth of 100 hertz. The information was stored on tape for off-line analysis. Some 150 hours of intermittent observation during a four-month period detected no recognizable signals.  A false signal was detected on April 8, 1960, but it was determined to have originated from a high-flying aircraft.<ref>{{cite book | first1=Jean | last1=Heidmann |last2=Dunlop |first2=Storm |title=Extraterrestrial intelligence | year=1995 | publisher=[[Cambridge University Press]]| isbn=0-521-58563-5 }}</ref>

The receiver was tuned to wavelengths near 21&nbsp;cm, which is the wavelength of radiation emitted naturally by interstellar hydrogen; it was thought that this would be familiar, as a kind of universal standard, to anyone attempting interstellar radio communication.<ref name="Darling">{{Cite encyclopedia |last=Darling |first=David |title= Project Ozma |encyclopedia=The Internet Encyclopedia of Science |url=http://www.daviddarling.info/encyclopedia/O/Ozma.html}}</ref>

A second experiment, called Ozma II, was conducted with a larger ({{convert|300|ft|m|sp=us}}) telescope at the same observatory by [[Patrick Palmer (astronomer)|Patrick Palmer]] and [[Benjamin Zuckerman]], who intermittently monitored 670 nearby stars for about four years (1972–76).<ref name="PZ">{{cite book |last1=Zuckerman |first1=Ben |last2=Tarter |first2=Jill C. |chapter=Microwave Searches in the U.S.A. And Canada |author-link2=Jill Tarter |title=Strategies for the Search for Life in the Universe |series=Astrophysics and Space Science Library |date=1980 |volume=83 |pages=81–92 |bibcode=1980ASSL...83...81Z |doi=10.1007/978-94-009-9115-6_10 |isbn=978-90-277-1226-4 }}</ref> They examined a 10&nbsp;MHz bandwidth with 52&nbsp;kHz resolution and a 625&nbsp;kHz bandwidth with 4&nbsp;kHz resolution.  The spectrometer was centered on the 21&nbsp;cm hydrogen line in the rest frame of each observed star.<ref name="PZ"/>

==See also==
* [[Ozma problem]]

==References==
{{reflist}}

==Further reading==
* Drake, F. D. "Project Ozma," Physics Today, 14, 140 (1961).
* Drake, Frank, "Project Ozma: The Search for Extraterrestrial Intelligence," Proceedings of the NRAO Workshop held at the National Radio Astronomy Observatory, Green Bank, West Virginia, Workshop No. 11, May 20-22, Kellermann, K.I., and Seielstad, G.A., eds., p.23 (1985).

{{Extraterrestrial life}}

[[Category:1960 in science]]
[[Category:1960 in West Virginia]]
[[Category:Search for extraterrestrial intelligence]]
[[Category:Epsilon Eridani]]
[[Category:Tau Ceti]]