Trip to the Australian outback part 2: the observatory

I wake up in the early hours, woken up by the sound of the cockatoos in the trees. But apart from the birds, nothing can be heard. I take a look outside my tent, dawn is starting, with orange and red colours creeping up and gaining on the pitch black night sky. Colours like these can only be seen in these remote places.

My little tent for the Murchison Astrofest in the Australian Outback!

My little tent for the Murchison Astrofest in the Australian Outback!

We are hundreds of kilometres inland, in the famous Australian outback, sleeping out in a camping after a night spent observing the night sky with our telescopes for the Murchison Astrofest, a highly successful outreach event held in the Shire of Murchison, celebrating astronomy and the region’s famous dark skies.

After packing up at sunrise, we have a hearty outback breakfast and head off for a very special day. Today, CSIRO is treating a select group of the astronomy volunteers who helped out yesterday during the Astrofest to a tour of the Murchison Radio astronomy Observatory – or MRO. With my colleague Kirsten, we are here representing ICRAR.

The MRO is the place where Australia’s part of the giant Square Kilometre Array telescope will be located. It will house hundreds of large dishes, and hundreds of thousands of radio antennas that we like to call “christmas trees”, see why for yourself:

The currently favoured prototype for the low-frequency antennas of the future SKA

The currently favoured prototype for the low-frequency antennas of the future SKA

But the MRO is already home to some pretty cool telescopes, and this is what we’ve come to see. We leave aboard a bus and head off on the dirt tracks, surrounded by flat land as far as the eye can see. We stop at Boolardy Station – where the CSIRO staff is housed – to pick them up, then are on our way. During the 45-minute journey, we cross path with cattle, sheep, kangaroos, and an emu on the little used dirt track. I wouldn’t want to get lost here!

Arriving at the entrance of the understated observatory – with a simple fence and no sign – we start driving down a much better track, improved for the trucks delivering the antenna parts. The antennas of ASKAP were built in China, one of the member countries of the SKA, then shipped by boat to Western Australia and re-assembled on site by the Chinese team. I’ve been told they exceed specifications.

We are on indigenous Wajarri Yamaji land, who are recognised as the traditional owners of that area. As such, a cultural and geographical survey was done prior to setting up the observatory to make sure no important places to the Yamaji people were damaged during the process.

We drive down the track and reach our first destination.

The Australian Square Kilometre Array Pathfinder

the unique green checkerboard Phased Array Feed (PAF) receiver installed on one of the ASKAP antennas.

the unique green checkerboard Phased Array Feed (PAF) receiver installed on one of the ASKAP antennas.

We start our visit with ASKAP, the Australian Square Kilometre Array Pathfinder. Made of 36 antennas, ASKAP is CSIRO’s SKA prototype array. Unlike other radio telescopes, the 12m antennas can move on 3 axes, and their green Phased Array Feeds or PAFs are a brand new design with a much wider field-of-view, developed by the Australian engineer behind Wifi, John O’Sullivan.

The array is still under construction as more PAFs still need to be installed, but it’s already an impressive sight, with its antennas standing tall above the outback shrub. We start our visit with the central building. To enter, we need to go through magnetic double doors, as the entire building is shielded to prevent any electromagnetic signals seeping out and disturbing observations. Not only the door, but also the water and air pipes are shielded. This being a radio observatory observing a large portion of the electromagnetic spectrum, your cellphone, radios, laptops, cameras and even car engine emit waves that would disturb the observations!

This is the supercomputer behind the MWA, which is housed in the MRO technical building

This is the supercomputer behind the MWA, which is housed in the MRO technical building

We make our way to the supercomputer, itself isolated behind more shielding. As we walk in, sticky dust mats capture the dust from our shoes to prevent too much dust accumulating in the room. The supercomputer is using geothermal power to cool it, digging down into the aquifer hundreds of meters below in a closed loop.

Of course, bringing electricity to such a remote location would be a major problem, and connecting the site to the power grid would be too costly. So to power it, the observatory is using a 2MW natural gas plant. It is expected that the SKA will require 40 to 60MW to function.

ASKAP Project Director Ant Schinckel tells us everything about ASKAP, notice the green Phased Array Feeds on top, ASKAP's revolutionary receivers

ASKAP Project Director Ant Schinckel tells us everything about ASKAP, notice the green Phased Array Feeds on top, ASKAP’s revolutionary receivers

We’re then taken for a drive through the array. More and more antennas appear, standing tall above the outback bush. We stop near the centre of the array, from which the antennas spread over several kilometers. There, ASKAP Project Director Ant Schinckel tells us more about the observatory. With a 12m diameter dish, and about 15m tall, the antennas offer an impressive sight.

The Murchison Widefield Array

We then head to the other telescope based at the MRO, the Murchison Widefield Array or MWA. This particular telescope is the first SKA precursor to be completed and operational, and  just started operations in early July 2013. It is being led out of Curtin University with a contribution from ICRAR. The MWA corresponds to the lower frequencies of the spectrum the SKA will cover.

The MWA consists of 2048 antennas spread on 128 “tiles” made of 16 antennas or dipoles fixed on a mesh, connected between one another by a simple cable. The MWA’s particularity? It has no moving parts, rather, the pointing is done electronically. It is also made of cheap materials readily available with little to no founding work. The result is a very mobile and scalable observatory. In fact, it was built in a matter of weeks by volunteers, the “student army”. You can read more about it here on Kirsten’s blog, who helped build it (how cool right?!).

the Murchsion Widefield Array, hidden among the outback flora

the Murchsion Widefield Array, hidden among the outback flora

As we start entering MWA territory, we start distinguishing small antennas camouflaged among the vegetation around. Some here, some there, is this really an astronomical observatory I think? How can these little things spread all over the place observe the sky and do science?

The MWA may not be “impressive” in terms of size, but its knee-high antennas made of cheap materials pack quite a punch. The fact that they are so small, made of such simple materials, and were built in so little time, does in fact make the MWA amazing. It’s amazing the science you can do with this.

Another view of a MWA tile, holding 16 antennas or dipoles.

Another view of a MWA tile, holding 16 antennas or dipoles.

Accumulating 400MB/s of data, the MWA is able to conduct surveys of the southern sky in very little time thank to a large field of view. It will also be used to study space weather by monitoring the sun’s activity and its flares, and will also be able to detect asteroids and near-Earth objects. This is a new age for radio astronomy, when observatories become scalable and all the clever complicated work happens inside computers.

Once processed by the supercomputer on site, the data is sent through a dedicated optic fibre all the way to Geraldton, the coastal city a few hundred kilometres away, and then from there through the National Broadband Network or NBN to Perth. The NBN is the next-generation broadband internet initiated by the Labour Government and currently being rolled out all over Australia. This portion of the NBN was the first to be built, precisely to support the development of the MRO. Once in Perth, the data is archived at the high tech $80M Pawsey Centre, a large building at Curtin University covered in photovoltaic tiles and cooled by geothermal energy. From there, the data is distributed to scientists around the world.

The MRO, with ASKAP and the MWA, is already quite an impressive observatory, and will take more importance with the construction of the SKA, the world’s largest scientific machine, which promises to make incredible discoveries. It’s a great opportunity for Australia and the region to be part of this revolution in astronomy and to have in their backyard such a powerful machine. It will bring jobs, money, and knowledge to the state, and quite possibly tourism to the area too. And what an exciting time for us to be living in this age!

As we finish our visit of the MRO and hop back on the bus driving on the dirt tracks of the unforgiving Australian outback, I start thinking about the MRO, and other observatories I’ve been to like the Pic du Midi in southern France, ALMA or Paranal in Chile. I find it amazing that humans would go through so much trouble to design these incredible machines, and place them in some of the harshest and most inaccessible places on the planet, just to “look” at our Universe. And for what reason? To try and understand, simply. Each observatory, each telescope, has a tale to be told. And every time, I feel privileged to visit such unique places, and feel even more respect for the men and women who build these machines and those who use them.

A souvenir photo taken at the MRO, with ASKAP antennas in the background, standing above the outback bush and dirt.

A souvenir photo taken at the MRO, with ASKAP antennas in the background, standing above the outback shrub and red dirt.

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