Mail
Will beaming songs into space lead to an alien invasion?
By DAVID DERBYSHIRE
Last updated at 00:42 07 February 2008
Comments (1) Add to My Stories
It's not as though Nasa is beaming out the Cheeky Girls back catalogue or the collected works of Florence Foster Jenkins.
Nevertheless, scientists warn that transmitting songs into deep space could put the Earth at risk of an alien attack.
They voiced fears that advertising humanity's place in the universe - as happened last week when Nasa broadcast a Beatles track towards the North Star - could attract the attention of aliens who are less friendly than ET.
Scroll down for more...
Under fire: Aliens destroy the White House in the film Independence Day
Dr Douglas Vakoch of the SETI Institute, which has been leading the search for extraterrestrials, told New Scientist magazine: "Before sending out even symbolic messages, we need an open discussion about the potential risks."
They voiced fears that advertising humanity's place in the universe - as happened last week when Nasa broadcast a Beatles track towards the North Star - could attract the attention of aliens who are less friendly than ET.
Dr Douglas Vakoch of the SETI Institute, which has been leading the search for extraterrestrials, told New Scientist magazine: "Before sending out even symbolic messages, we need an open discussion about the potential risks."
A recording of the Beatles' Across the Universe was last week beamed in the direction of Polaris, also known as the North Star, by Nasa.
SETI - the Search for Extraterrestrial Intelligence - plans more broadcasts from its base in Mountain View, California.
Adorable: But extraterrestrials might not be as friendly as ET
For the last 20 years, it has used radio telescopes to scan the skies for alien radio messages.
After getting nothing but static, some of its researchers have decided that listening for aliens is not enough.
Instead, they say, we should be actively sending out friendly signals to the stars.
Dr Richard Gott, an astrophysicist from Princeton University, told New Scientist: "SETI's big mistake is that it's relying on ET to do all the heavy lifting.
"We'll all just be sitting round listening, but nobody's doing any talking."
A group of scientists is calling on SETI to broadcast a simple pulsed signal that reveals the presence of intelligent life on Earth.
Others want more recordings of the type included with the Voyager and Pioneer space probes.
Nasa attached engravings depicting humans and our planet to the outside of the craft, and aboard it put tapes of voices, birdsong, music, and maps of where Earth is.
"It's very charitable to send out and encyclopaedia, but that may short-change future generations," said Dr Vakoch.
Professor Barrie Jones, an astronomer with the Open University, added that there is an "unofficial embargo" about alerting potentially unfriendly species to our presence.
"The chances are slight, but the consequences would be huge - the end of life on Earth," he said.
"When you look at the history of colonisation on Earth, it is pretty bloody awful.
"If they have the technology to cross interstellar space to reach us, they will be so much in advance of us humans that there is nothing we could do to resist them."
However, other astrophysicists point out that humanity has been advertising itself to neighbouring stars since the first commercial radio transmissions of the 1920s.
By now, those early broadcasts will have travelled nearly 90 light years - some 540trillion miles.
Radio waves, like other forms of electromagnetic radiation, travel at the speed of light - around 186,000 miles per second.
This means it would take a radio broadcast four years to reach the closest star, Alpha Proxima, which is just over four light years away.
But at least one physicist at SETI is confident that "first contact" will be more like Steven Spielberg's friendly ET and less like Ridley Scott's horrifying Alien.
Dr Seth Shostak said that if there are any extraterrestrials listening out for us, they will have already had plenty of experience of Earth's culture.
He is sanguine about the possibility of unfriendly attention, saying: "It's quite paranoid, given that the one thing we know about aliens - if they do exist - is that they are very, very far away.
"Military radar signals have already penetrated deep into space and
early broadcasts of Star Trek and I Love Lucy are washing over one star system a day.
"If they're listening, they already know we are here."
