Frugal Aliens Might Be Sending in a Cost-Effective Way
The Search for Extra-terrestrial Intelligence (SETI) has been the focus of a dedicated group of scientists for the past 50 years. The process, developed in the 1960s, involves listening for signals from nearby stars and trying to decipher any type of intentional message from among the noise of space. And, make no mistake about it, space is noisy.
No signals have been found yet, and that has some researchers wondering if there isn’t a better and more cost-effective way to monitor signals. But, has anybody thought about what sending messages across space might cost a civilization? Gregory Benford, an astrophysicist at University of California-Irvine is. He’s teamed up with his twin brother James, who is a physicist specializing in microwave technology, to look at the problem from the point of view of the folks on other worlds who we have been hoping were sending messages to us. Their conclusions, publihsed in the June of the journal Astrobiology, assume that any alien civilization might want to save money and resources and send their messages in the most cost-effective way possible. This means optimizing the use of bandwidth and sending narrowly focused beams that carry pulsed signals in the 1- to 10-gigahertz range.
James Benford likens that approach to being more like Twitter, with its shortened, efficient methodology of sending messages. James and Gregory (who is also a science fiction writer) have caught the attention of the SETI community with their so-called “Benford Beacons”. Researchers are taking a look at their current efforts, which focus their receivers on narrow-band input. They’ve come to the conclusion that they may be looking for the wrong kind of signals. The Benfords and a growing number of scientists involved in the hunt for extraterrestrial life advocate adjusting SETI receivers to maximize their ability to detect direct, broadband beacon blasts.
Once that’s done, the next question will focus on where to look for these little beacons. The Benfords suggest star-rich areas of the Milky Way, particularly toward the center where stars are at least a billion years older than the Sun. Those stars might stand a good chance of harboring life of the intelligent variety.
To hear more about these Benford Beacons, watch this video interview with James Benford.
If you’re interested in learning more about all the aspects of SETI, consider attending SETICon, being held August 13-15, 2010. Details at are SETIcon.com.
In a white paper released yesterday, available online now here, astronomers address the question of where in the sky would be good candidates for observing the micro-lensing effects of exoplanets. Gravitational micro-lensing is a technique which utilizing the General Relativisitic effect that gravity has on light, allowing any massive object to act like a lens if directly in line with light from a more distant object. The authors argue that “out of the five popular planet detection techniques,
Gravitational Microlensing is the most capable of detecting rocky, earth-sized planets and seems to be more promising in the search for other habitable worlds.” Thus, they offer to astronomers “a distribution map for probability of finding stars within the Milky Way Galaxy that could harbor terrestrial planets capable of hosting life, with a particular emphasis on the Microlensing detection of exoplanets.”
If you like puzzles you may like to try your hand at interpreting a message that was designed to be sent to an extraterrestrial intelligence. In an attempt to simulate an exchange of information via intelligent civilizations, scientists from Cal Tech (Busch) and Stanford (Reddick) developed a method for coding a message and tried to see if it could properly be decoded. The paper and code are available online here. If you are up for it, you too can see if you could have interpreted this message. Such message exchanges require much intelligence on both sides of the message, the sender and receiver.
In a paper published in the Serbian Astronomical Journal, available online now here, astronomers re-examine the widely known Fermi Paradox. Fermi expressed this paradox in the early 1950s in a debate with colleagues who felt that there must be many instances of intelligent life in our galaxy (extraterrestrial life). However, the search (SETI) for extraterrestrial life has yet to find any. He ended his argument by asking simply, “so where are they.” There is an entire book about this subject, originally published in 2002. You can check it out online here. The aforementioned journal article has a European flavor to it, and gives more of a history to the question in general.
Most are familiar with the acronym SETI, which stands for the search for extraterrestrial intelligence. Most SETI research has focused on attempts to detect radio frequency signals from other civilizations. Optical SETI (OSETI) is the search for extraterrestrial signals in the optical wavelengths. It’s based upon the premise that a civilization using a high powered laser could more efficiently send out a message via such a focused laser beam in the direction of another civilization. In a concerted effort to detect such a signal from 187 nearby candidate stars, a team of astronomers has reported that they could not detect any such signal. The instrument used for this search was the Solar Tower Atmospheric Cherenkov Effect Experiment or STACEE for short. Located in New Mexico near Albuquerque, the instrument consists of 224 steerable mirrors, originally designed for solar energy research. Learn more about this OSETI effort online now here.
The Allen Telescope Array (ATA) is a unique array of radio telescopes in Northern California at Hat Creek Radio Observatory. The array is hoped to eventually contain over 340 small radio telescopes linked together to function as one big radio telescope. Each of the small radio antennae is a type available “off-the-shelf” commercially. This was done to save money and build more rapidly than usual. Currently the number of radio telescopes linked together for use is 42. Using these 42 dishes (known as ATA-42), astronomers and engineers have released the first images (first light) using this configuration. ATA is planned for standard radio astronomy projects as well as SETI (Search for Extraterrestrial Intelligence). Read more (and see some first light images) about this unique radio astronomy collaboration and facility in a paper to be published by the IEEE (Institute of Electrical and Electronics Engineers) available online now here.
In a white paper released today, a group of American astronomers provide an outline about the future of radio astronomy for the next ten years, given the proper funding. Radio astronomy is expected to bring major advances in the understanding of “orphan gamma-ray burst afterglows, radio supernovae, tidally-disrupted stars, flare stars, magnetars, and transmissions from extraterrestrial civilizations.”
Astronomers from UC Berkeley released an update on their search for extraterrestrial intelligent radio signals in space in a report to be published in a future issue of Acta Astronautica. You can see their report now online at http://xxx.lanl.gov/PS_cache/arxiv/pdf/0811/0811.3046v1.pdf While their systems, affectionately called Astropulse and Fly’s Eye, have yet to discover any signals from an ET, they did detect three pulsars and six “giant pulses” from the well known Crab Nebula pulsar. If you’d like to participate in the data analysis of the signals from these experiments, you can do so by downloading their software which you can find online at http://setiathome.berkeley.edu/