It’s rare to meet someone who claims to have the best job in the world but the architect of what will become the largest scientific instrument on the planet believes he has it. Tim Cornwell is part of the team, based at Jodrell Bank in the UK, who are building the Square Kilometer Array (SKA), a series of linked radio dishes that collectively will create the biggest and most sensitive radio telescope in the world. Once completed it will have a total collecting area of over 1 million square meters and will be so sensitive that it would be able to detect an airport radar signal on a planet tens of light years away. Cornwell, who is lead architect on the telescope, has spent his career working in the field and his passion for radio astronomy is clear, “The thrill of building radio telescopes and seeing things people have never seen before is just amazing” he says. The SKA will be built across two sites, in Australia and South Africa, areas deliberately chosen for their ‘radio quietness’, where the lack of population means a corresponding lack of noise and therefore lower risk of interference from radio devices.
For non-scientists radio astronomy may not immediately spark excitement but the aims of the SKA are relevant to everyone. Using the SKA scientists will address some of the greatest unanswered questions of our time, including, how do galaxies form? What is dark energy? Was Einstein right about gravity? And perhaps most alluring, are we alone in the Universe? As SKA project scientist Tyler Bourke puts it, “We will have the sensitivity and the view of the sky to detect leakage equivalent to normal TV signals or radio stations from other planets up to a significant distance. It comes to the point where we should be able to hear something.” In that typical understated fashion common to scientists Bourke goes on to say that if the telescope doesn’t pick up anything then “it causes us some problems”, in effect if the SKA doesn’t hear anything we would know that it’s highly likely we are the only complex lifeform in the Universe. Of course looked at the other way, as suggested on their website “the detection of any extraterrestrial signals would forever change the perception of humanity in the Universe.”
Given the magnitude of the scientific questions it will seek to tackle, by the time it’s switched on the SKA will likely be as much of a household name as the Large Hadron Collider. Before then though there is significant work to be done.
Although the SKA headquarters are at Jodrell Bank in the UK, the project itself has 11 participating member countries and coordinating input and feedback from all participants is clearly a mammoth task. The first phase of the project is to finalise the detail of the design of the telescope, this also has to consider questions such as how they will manage, move and process the huge amount of data a telescope of this size will generate. Processing the data will be in itself a massively complex task and as part of this initial design phase, the team has been talking to processor manufacturers like Intel and Nvidia about what may be possible. They’re also in discussions with Amazon about the possibility of using the Amazon cloud to do their processing. Whatever the final solution Tim Cornwell provided some context for the size of the task they face, “We have to go up a huge amount in processing scale, the fastest telescope in the world at the moment is LOFAR and we’re going to go about a 1000 times faster than that.” It has also been described as having the processing power of about one hundred million PCs. The sheer volume of data that will be created by the telescope will mean it will be impossible for them to keep it all. Cornwell explained how they will handle the data, “We’ll process it into science products, like images of the sky, and then we’ll throw away the raw data. If you didn’t do it this way it’d cost hundreds of millions of Euros to run it every year.”
Another logistical challenge is how they will power the SKA. An instrument of this size will require significant power to operate and in order to extract and process the data. And while a major factor as to why the selected sites were chosen was due to their remote, quiet location, in Australia, this remoteness brings with it the challenge of being off grid.
Once the final design in agreed, in 2018, construction will begin, this will take place in two phases, but by 2020 they will be able to begin some initial work, what they refer to as “early science”. By 2024 the telescope should be completed.
Even at this relatively early stage in the life of the SKA scientists from around the world are excited about the possibilities and are currently submitting their ideas and plans for the experiments they’d like to carry out using it. And although the big high-level questions have been set out, in common with many large-scale exploration projects, it’s likely that it will discover something that hadn’t even been considered. When you look at it that way it’s easy to understand why this team of passionate scientists and radio astronomers talk about having the best jobs in the world.