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Scientists have tested a unique telescope in Vancouver’s waters as they bid to open a new window onto the universe.

But this is no ordinary telescope: it is the first line of a next-generation neutrino telescope that will be plunged thousands of metres into the Pacific Ocean.

We caught up with 51ÁÔÆæÈë¿Ú physics professor, Matthias Danninger, the project’s scientific spokesperson, to find out more. 

What is a neutrino telescope? 

It is not what you might imagine a telescope to be. It’s a particle telescope. It observes the light emitted from particles that are created when neutrinos interact in the detector. Neutrinos are these very obscure, fundamental particles of the universe.

What we’re working on is the Pacific Ocean Neutrino Experiment (P-ONE) – the next generation of neutrino telescope. Our aim is that it will eventually consist of dozens of mooring lines, each around one kilometre in length, anchored to the ocean floor, covering an area of roughly one cubic kilometre.

Each line features optical modules, spaced 50 metres apart, which are large spheres made from thick, pressurized glass. They contain a variety of sensors and calibration instruments, of which the most important are photomultiplier tubes – super sensitive light sensors.

It’s been a huge collaborative project. We have built components right here at SFU, such as precision calibration detectors, high-power light emitters that shine strong lights hundreds of meters into the ocean to calibrate the optical properties of water. 

The first line that we tested recently has been assembled at TRIUMF, in Vancouver, using components that have been provided by project teams dotted across the world.

When we deploy it in the fall, it will work in conjunction with a cabled network spanning several thousand kilometers across the ocean, developed by (°¿±·°ä). &²Ô²ú²õ±è;&²Ô²ú²õ±è;

What is a neutrino?

Neutrinos are subatomic particles that travel close to the speed of light. They are very abundant, but they have nearly zero mass and barely interact with anything. These characteristics make them a perfect messenger for studying distant and extremely energetic objects in the universe.

But it is exactly these illusive traits that make neutrinos very hard to catch. This is why neutrino telescopes cover such a large area as it improves your chances of detecting an interaction.

When high-energy neutrinos interact in the detector, they create a spray of particles that pass through the water. As these particles travel through the water, they emit some light, known as Cherenkov light. It’s this light that we capture with our grid of detectors.

By measuring the intensity and exact arrival time of this light with our detectors inside the glass spheres, we can infer the properties and direction of the neutrino.

The same principle works in clear ice. That’s why you find neutrino telescopes using deep ice or located in large volumes of water. For example, the IceCube Neutrino Observatory uses a cubic-kilometer of Antarctic ice.

What do you hope to learn from this experiment?

There’s a really wide range of research that you can do with a neutrino telescope. First and foremost, it will open up a new window on to the high-energy universe.

Think of neutrinos as messengers of something that has happened in the universe. For example, a huge, violent explosion of stars. Or active galactic nucleus, which are kind of supermassive black holes at the centre of a galaxy that emit a lot of radiation and particles.

Scientists can observe these types of objects with telescopes that measure electromagnetic emissions, such as light, X-rays, and gamma rays. In addition, gravitational waves might be emitted from such objects.

When you bring all these messengers together and add neutrinos, you can start to form a coherent picture of what is happening in the universe and start to understand some of the most enigmatic places in the universe.

The equipment will also gather data for research into ocean science, climate change, tectonic plate movement off the B.C. coast, and it has the potential to track the migration of whales and provide a deeper understanding of marine biology. 

What was the test about?

The deep ocean is an extremely challenging environment in which to operate highly sensitive equipment. We know what we’ve built so far works as expected in our lab. But we need to do a dedicated wet test, which is what we did in the Granville Island Boatyard at the end of June.

The test is performed in shallow water to eliminate any kind of electrical issues and make sure the instruments work as they should do. We want to give ourselves the best possible chance of success.  

What are the next steps?

Once we’re happy that everything works in water, our plan is to deploy the line in the ocean, hundreds of kilometres off the coast of Vancouver Island, in the fall.

It will be lowered to the ocean floor, which is roughly 2,700 metres down, by remote operated vehicles, and connected to one of ONC’s cabled observatory networks, called Neptune at Cascadia Basin.

It has taken three years to get to this point, which is exceptionally fast for such a complex system with so many components.

The first line is an exciting start. We’ll use it to collect as much data as possible to learn about this new and exciting detector system and to perform a plethora of calibrations. But of course, we can’t do cutting-edge neutrino physics with one line.

With the funds that we have currently, our aim is to scale up so we can get four or five lines deployed. We call this the ‘demonstrator phase.’

Our ultimate goal, if funding permits, is to get around 100 lines. That then becomes a very large experiment and would give us the scientific capabilities far beyond anything that exists currently.  

How are 51ÁÔÆæÈë¿Ústudents involved?

Our students are super excited to be working on this project. It’s been great seeing their response and enthusiasm. Everything we do is curiosity driven. You want to understand more, to learn about the universe, how it all interacts.

What’s really awesome is we are in a position right now to really try to shape a scientific field, we’re not just trying to be part of something. We have a really exciting vision that could shape this field over 10 or 15 years, if we get the funding to build a full array of lines.

It’s super fun to try to do this in Canada and you can see how much the students enjoy contributing.  

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