The mission of the SETI institutePosted by shaik on Thursday, November 5, 2009
Under: science & technology - the latest revolutionary experiments
Join TeamSETI today to order an autographed copy of Space Exploration for Dummies, by SETI Institute scientist Cynthia Phillips, PhD. Membership benefits include: Our science magazine, Explorer, Advanced notice for special member events, access to exclusive web features such as our online member's only forums, membership card, discounts on merchandise and more... Join TeamSETI TODAY and get in on the search! http://www.seti.org/Page.aspx?pid=1366
SETI at 50: 10 key moments in the search for extraterrestrial lifeThe Search for Extraterrestrial Intelligence, or SETI, is 50 years old this month. We look at 10 memorable events in the search for life on other planets.
By Tom Chivers Comments 2 | Comment on this article In 2015, Voyager 1 will become the first man-made object to leave the solar system Photo: NASA SETI was founded in response to a September 1959 Nature journal article, “Searching for Interstellar Communication”, which suggested that a systematic search for alien life was worthwhile. Since then, it has spent 50 years listening to the stars with radio telescopes, and at times trying to send messages of its own to other planets.
Related Articles· Found: hell planet where rock falls as rain· Beatles space broadcast 'risks alien attack'· Mars ancient water discovery· Google shows history of MarsHere are 10 of the most significant events in mankind’s search for other life. Little Green
Men: Pulsars What was unexpected, though, was that this one turned itself on and off with perfect regularity: one 0.04 second pulse every 1.3373 seconds. The metronomic beat sparked speculation that it might be a signal from an alien life form, and the signal was given the name LGM-1, standing for Little Green Men. In fact, the astronomers had discovered a new type of star – a pulsar. A form of neutron star (an incredibly dense dead star: one just 12 miles across would weigh more than our Sun), they rotate at a huge velocity, giving off powerful beams of radiation as they spin. Martian
bacteria? It then wandered through space for millions of years, before crashing into our planet about 11,000 years before the birth of Christ. An interesting enough history, but the meteorite – known as ALH84001 – really made the headlines in 1996. Structures that resembled tiny fossilised bacteria were found, as were organic molecules, sparking theories of ancient life on Mars. The excitement grew so great that US President Bill Clinton made a televised announcement about the find. Arguments over whether these really are evidence of Martian life, or whether the sample has become contaminated during its time on Earth, are still raging today. Earth-like
planets But in the last few years, the first possible examples of Earth-like planets outside our system have been found. In 2007 European scientists said they had found two – the third and fourth planets around the red dwarf Gliese 581 – which might be habitable. Water
on Mars Water is required for all known forms of life, so the existence of water on other planets increases the likelihood that life exists elsewhere. Drake
equation It states that if we know the rate of star formation, the percentage of stars that have habitable planets, and the percentage of those planets that are likely at any given time to support life that signals its existence to the universe, we could estimate how many civilisations in our galaxy we might communicate with. Unfortunately, none of those factors are known, so we are still guessing. The
Aricebo Message Sadly, M13 will have moved by the time it arrives. A later broadcast - beaming the music of the Beatles at the Pole Star, 431 light years away - was, in all apparent seriousness, condemned as inviting an interstellar attack from warlike aliens. Voyager In May 2005, NASA scientists said that Voyager 1 had reached the heliosheath, the boundary that marks the edge of the solar system. It is expected to pass through into interstellar space in 2015, becoming the first man-made object ever to leave the Sun’s orbit. Kepler telescope
It is designed to find small planets by watching stars closely to see if they suddenly get dimmer, indicating that something has passed in front of them. For an Earth-sized planet, that would mean the star becoming dimmer by just 0.01 per cent. The
Wow! signal and Radio
source SHGb02+14a However, it was never spotted again. After he had calmed down, the discoverer Dr Jerry R Ehman said he believed it was “an Earth-sourced signal that simply got reflected off a piece of space debris.” Another candidate for evidence of alien life was SHGb02+14a, a signal spotted three times in March 2003. It was at a frequency expected to be used by extraterrestrials – the frequency at which hydrogen absorbs and emits photons. However, again there were reasons to be sceptical, not least that it came from a direction in which there are no stars for 1000 light years. While impossible to rule out extraterrestrial origin, it may have been a distorted signal from a pulsar, or just random noise. SETI@home
Launched in 1999, SETI@home is the name given to a virtual supercomputer made of huge numbers of internet-linked home computers. Anybody can download the software and allow SETI to use their spare processing power to scour data from radio telescopes for evidence of alien intelligence. In terms of power it is the fourth most powerful computer on the planet. It was this network of home computers that spotted SHGb02+14a, and one NASA scientist has predicted that it will find an alien signal by 2025.
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Very well put article, thanks. Thade on September 30, 2009 at 08:19 AM ·
Though the search for extraterrestrial life is
among the most uncertain of all explorations, for me it's also among the very
most exciting. That's why I joined the SETI@home network early on, as soon as I
learned about it.
http://www.telegraph.co.uk/science/science-news/6240998/SETI-at-50-10-key-moments-in-the-search-for-extraterrestrial-life.html In : science & technology - the latest revolutionary experiments |
The mission of the SETI institutePosted by shaik on Thursday, November 5, 2009
Under: science & technology - the latest revolutionary experiments
In : science & technology - the latest revolutionary experiments |