Telescope Cluster For SETI

ContinuousPark writes: "MSNBC is reporting that radioAstronomers showed today the Rapid Prototype Array, which consists of seven 12-foot off-the-shelf satellite dishes, set up at the Russell Reservation near Lafayette, CA. This experiment, in which computer software will control the drive systems of the dishes and process all gathered information, is going to tell astronomers how to build much bigger radio telescope arrays such as the 1-hectare telescope and the Square Kilometer Array; the SKA would be 10 to 100 more sensitive than the Arecibo radiotelescope. Check out the SETI Institute press release and photos. "

Comments

Optical SETI

[lythari]

A Recent development in the SETI programme is optical SETI. As the name suggests, this attempts to detect any transmitions sent using light in the visible part of the spectrum. The concept for optical SETI isn't new. However, it was only recently that it has been put into practise. The latest issue of the Planetary Report (the bimontly magazine of the Planetary Society) has an article of Optical SETI which I will attempt to summarize below. The advantages of sending signals using visible light over radio waves are

1)transmitted beams of visible light (ie. lasers) can be finer than beams of radio waves due to the higher gain of optical telescopes. I suppose this means that the signal can be more concentrated and thus brighter and more easily detected.

2)visible light doesn't disperse as much as radio waves. This also increases the intensity of the signal.

3)the capabilities of radio transmitters has hit a brick wall while optical lasers continue to increase in power. This is assuming that an alien race is similarly limited as to the power of their radio transmitters. All this leads us onto the question of how effective signals sent with visible light are. The answer is very. The article says that with our current technology, we can send laser transmitions that would outshine the background light from our sun by 5000 times. So assuming that an alien civilisation has more powerful lasers than us, we should easily be able to detect any signals they send in our direction.

Also, the equipment needed for an optical SETI search is very simple. All it involves is a pair of photon-detectors. Current optical SETI equipment works on the premise that any optical signals from alien civilisations will be sent in pulses. I haven't had time to purse the explanation on how the detector works so I can't tell you yet. Perhaps someone else with access to the latest Planetary Report could help out here.