Earlier versions of this article about Project Dorothy, astronomers' first broadly international search for extraterrestrial intelligent life, incorrectly referred to the character after whom the initial such experiment was conducted 50 years before, Princess Ozma, as appearing in the book "The Wizard of Oz." Ozma appeared in subsequent books in the Oz series but not that one. This version has been corrected.
A global extraterrestrial pursuit
The scientific search for extraterrestrial intelligence went global this weekend as observatories in 13 nations on five continents trained their telescopes on several promising star systems.
While they don't expect their one-day joint effort will find the kind of intentionally produced signal from afar that enthusiasts have been seeking for decades, participants say the undertaking illustrates just how far the search for extraterrestrial intelligence, or SETI, has come.
Frank Drake made the world's first such observations at the Green Bank radio telescope in West Virginia 50 years ago, listening on a single-channel receiver that took in radio waves one frequency at a time. Today's technology allows scientists to receive radio signals at millions of different frequencies per minute, in addition to searching for laser-like bursts of light communication using optical telescopes.
The international star-viewing extravaganza, the first of its kind, comes at a time of fast-paced discovery in the science of exoplanets, bodies that orbit suns beyond our solar system.
Last month alone brought the announcement of the first Earth-sized planet found that appeared to be potentially habitable, as well as a study from top scientists in the field which concluded that the number of Earth-sized planets in the Milky Way alone could be counted in the tens of billions.
Suddenly, the prospects for finding planets that might have complex life and environments to support it appear to have brightened. Scientists well in the future may still conclude Earth is the only planet that harbors life, but discoveries in the last few years seem to increase the odds that we are not alone after all.
"This is a real coming of age for exoplanets and for SETI," said Drake, who remains active in the field and whose founding of the science of SETI five decades ago was being commemorated as well over the weekend.
"It shows SETI has gone truly international, and it's happening when our knowledge about planets beyond Earth is just exploding," he said. "We made predictions based on weak evidence 50 years ago and now a lot of that is, very satisfyingly, getting hard scientific support."
Doug Vakoch, a SETI Institute scientist who helped organize the effort, said the coordinated observing is probably most important for its practical side.
"What this weekend really does is begin the process of making it possible to track a possible SETI signal around the globe," he said. "If a signal is detected, it has to be confirmed and followed, and now we're setting up a network to do that."
The participating observatories are in Italy, India, Argentina, Australia, France, Germany, the United Kingdom, South Korea, Sweden, the Netherlands, and several in the United States and Japan. Officials at the largest radio telescope in the world, Arecibo, will also participate.
The idea for the unprecedented global observation was initiated by Shin-ya Narusawa, director of Nishi-Harima Astronomical Observatory in western Japan - one of the largest observatories in that country. Narusawa organized a many-centered SETI observation in Japan last fall, and was invited to present his results at the biannual NASA-sponsored astrobiology conference held this spring.