The iconic Parkes radio telescope in New South Wales, Australia has witnessed the birth and death of star systems, unravelled cosmic mysteries and even relayed the first live TV pictures of astronauts on the Moon.
The walls of the doughnut-shaped control room underneath the vast 64-metre-wide dish are lined with racks of equipment. There are cabinets of flashing LEDs, switches, dials, and stacks of processors and hard-drives. Since its first observations in 1961, the technology has been continuously upgraded. Well, most of it.
“We’ve recently upgraded the computer,” says operations scientist John Sarkissian from the Australian national science agency, Csiro (Commonwealth Scientific and Industrial Research Organisation). “We’ve stuck an Apple sticker on it.”
The computer in question is used to manoeuvre the Parkes dish with pinpoint accuracy to detect radio signals from distant galaxies. But this Digital Equipment Corporation (DEC) PDP 11 was built long before any modern incarnation of a Mac.
“It doesn’t have an operating system, so it doesn’t crash,” says Sarkissian. “It’s very stable and reliable – we have the attitude that if it’s not broken, don’t fix it.”
This beige box with three switches and ‘Digital’ printed helpfully on the front, has been running without incident since 1982. And it will soon be operating alongside the latest generation of processing technology.
“Over here we have four shielded racks,” says Sarkissian, walking around to the opposite side of the circular room. He opens one of the metal cabinet doors and we are hit by a blast of icy air. “There’s going to be so much equipment in here, it’ll heat up quickly so we need to be able to cool it.”
This is a fresh look at the search for extraterrestrial intelligence with new technology and new motivation to try harder – John Reynolds, Csiro
The technology generating so much heat is being used for a major new search for extraterrestrial life known as Breakthrough Listen. The global project, involving radio telescopes around the world, is backed by billionaire Yuri Milner and supported by Stephen Hawking. From early 2017, detecting possible alien signals from space will take up a quarter of the Parkes observation time.
“This is a fresh look at the search for extraterrestrial intelligence with new technology and new motivation to try harder,” explains the programme director at Csiro, John Reynolds.
“Computers have been getting more powerful every year,” says Reynolds. “The technology we’re using is built around something called the Graphics Processing Unit – this is the technology that lets gamers have fun, renders images really quickly on screens and has revolutionised computer processing.”
Ideally an alien race would transmit a pure tone or beacon across the cosmos to anyone who might be listening. But, if they are anything like us, a more likely scenario is that they will accidentally alert us to their presence. And that requires new hardware to make sense of the transmission.
“If you’re looking for a signal from a distant planet that’s not intended to be received then you might look at the sort of signals that would be visible from Earth,” says Reynolds. “One might be the GPS signal – that’s a complex signal that doesn’t pop out in a simple display and requires a lot of processing.”
As well as the computers, the Parkes dish is being upgraded with a new array of 13 receivers – allowing it to look in 13 different directions at once.
Considerable thought has gone into the areas of the sky the scientists are targeting
“The amount of data we’ll be getting will be phenomenal,” says Sarkissian. “Every day we’ll be collecting many terabytes of data.”
Considerable thought has gone into the areas the scientists are targeting. As well as looking at possible Earth-like planets around our nearest stars, they are pointing the telescope at galaxies far, far away. Hundreds of light years away, in fact.
“You’d have to be an incredibly advanced civilisation to transmit something from that distance,” says Reynolds, “but that’s what we’re looking for – it’s likely that any detection we find will be from a civilisation that’s way more advanced than us.”
The chances of an unexpected signal being of alien origin are ranked on the Rio Scale and there have been plenty of false alarms over the years. Many, however, have turned out to be scientifically important.
In 1967, for instance, Cambridge radio astronomer, Jocelyn Bell-Burnell, discovered a regularly pulsating signal coming from a distant star system. Initially termed LGM, standing for Little Green Men, it was found to be a new type of neutron star known as a pulsar. As they rotate, these dead stars emit a repeating beam of electromagnetic radiation across the cosmos.
Some signals though are simply fake. “WTFs is another acronym for them,” says Reynolds. One occurred a few years ago at Parkes when astronomers were seeing signal spikes in their data. These anomalies seemed to occur every lunchtime. “It was reasonably obvious what we were looking at must be terrestrial, even though they resembled the celestial signal we were looking for.”
We think we have the tools and know-how to separate the real from the fake – you just have to be very careful – John Reynolds
The mystery signals turned out to be coming from microwave ovens used by workers on the site. “We think we have the tools and know-how to separate the real from the fake – you just have to be very careful.” Microwaves have since been banned.
If, after checking, any signal does seem likely to be alien in origin, Breakthrough Listen has a procedure in place to make sure the news reaches the world. “You have to be very careful not to jump off too early and claim something that turns out to be false,” says Reynolds. “We’ll take great care to ensure that anything we announce is thoroughly verified and very high on the Rio Scale.”
What are the chances then of this project succeeding where others have drawn a blank?
“One of the fundamental problems with being involved in this is the low probability of success,” admits Reynolds. “There’s not much question that we’re not alone in the universe. If we look hard enough we’ll find it… it’s just a question of when.”
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