Nanaimo Astronomy Society members will take a deep dive into undersea astronomy with two presenters from Ocean Networks Canada at the society's meeting this week.
It’s well known that massive amounts of charged particles spewed from the sun's solar flares can impact power grids, communication networks and navigation systems on and above the surface of the Earth, but during strong solar storms in 2024, researchers discovered the flares also impacted Earth’s magnetic field so strongly that compasses on research instrumentation anchored to the ocean seabed swung erratically away from pointing toward magnetic north.
“Our instruments are deployed and they’re fixed to the sea bed, so the compass, you’d never expect to see change except if our instrument is tilted over or a whale whacks it with its tail or something like that, said Benoît Pirenne, ONC's corporate innovation and technology officer.
In March one of the researchers noticed instrument compass readings were “all over the map” for several hours. A strong solar storm in May caused underwater instrument compasses, some as deep as 2.6 kilometres, to react again.
“It was confirmation that geomagnetic storms from the sun can be picked up, not just on the land surface, or in the air or in nearby space, but also deep in the water,” Pirenne said.
At this week's astronomy club meeting, Kate Moran, ONC president and CEO, will share in detail how understanding the geographic extent and intensity of solar storms might provide useful data for researchers. As well, Pirenne will explain how a proposed underwater observatory will literally go to great depths to help detect major cosmic events, such as supernovas and black holes, by capturing tiny sparks of light created by high-energy neutrinos – elusive subatomic particles produced by nuclear reactions in the sun, radioactive decay, exploding stars and black holes – as they collide with particles while passing through the Earth.
“What has happened more recently in astronomy … is that we’re starting to observe the universe using different things than just photons, light, radio waves and so on,” Pirenne said. “Those other things include gravitational waves … Another one is other particles, such as neutrinos.”
Neutrinos have almost no mass, and are electrically neutral, so don’t tend to react with anything, and pass through our bodies and the Earth unnoticed at nearly the speed of light unnoticed. But some especially high-energy neutrinos – those ejected from sources like black holes and supernovae – pack enough punch to cause photons to be released when they do strike particles. Those tiny bursts of light can be detected and the data collected from them can be used as another way to look at the universe.
Detecting neutrinos is becoming important in studying difficult-to-observe events happening millions of light years from Earth, such as the merging of black holes or colliding neutron stars, which release huge amounts of energy including gravitational waves and neutrinos.
“All these techniques together, the neutrinos, the gravitational waves and so on … form what is now known as multi-messenger astronomy,” Pirenne said. “So you’re using different pieces of information, coming at different times, using different detection capabilities, to figure out what happened.”
Photons from neutrino-particle collisions are best detected by telescopes in large dark areas, such as the IceCube observatory deep within the ice of Antarctica, or the depths of the Pacific Ocean off Vancouver Island.
The Pacific Ocean Neutrino Experiment is a proposed neutrino observatory to be installed 2,600 metres underwater off the west coast of Vancouver Island. The first neutrino detector component of what is planned to be a modular underwater large-volume telescope more than one cubic kilometre in volume, will be installed in 2025. P-ONE is an international collaboration between Canadian, U.S. and European research and funding. Ocean Networks Canada will host the neutrino observatory, deploy the system and provide the telescope’s power and its control and data communication system.
The telescope proposed, if fully built out into the 2030s, depending on funding, will consist of 70 one-kilometre-long optical detector strings, each with a minimum of 20 detector modules containing 16 photomultiplier tubes per string, moored to the seabed and tethered together by data communication and power cables.
Each instrument string and deployment frame weights about seven tonnes, Pirenne said. Performing 70 installations from a ship at sea will be challenging as will processing the collected data.
“It’s a lot of sensors and a lot of data,” he said.
Nanaimo Astronomy Society's next meeting is online only via Zoom on Thursday, Nov. 28, at 7 p.m. To attend as a member of the public, e-mail info@nanaimoastronomy.com for the Zoom invite link. To learn more, visit www.nanaimoastronomy.com.
