CHIME

UBC physicist Mark Halpern and Kirsty Duncan, formerly the federal science minister, descend from part of the CHIME telescope at its unveiling in 2017.

Astronomers working to unlock some of the deepest mysteries of the universe using a radio telescope near Penticton are planning to add a second “ear” to their system.

The new telescope would be built on a cattle ranch near Princeton that’s 85 kilometers west of the Dominion Radio Astrophysical Observatory, which is home to the Canadian Hydrogen Intensity Mapping Experiment.

CHIME isn’t a telescope in the traditional sense and has no moving parts. It consists of four steel frames that look like half-pipes and are wrapped in wire mesh. Each is 20 meters wide and 100 meters long, and together they form an array the size of six NHL rinks.

The new detector would be similar in design to the original, but only about a tenth of the size with a single half-pipe that’s 20 meter wide and 30 meters long.

By comparing the radio signals received at the two sites, scientists hope to pinpoint the galaxies from which they’re coming.

“If you hear something in only one ear, you don’t have a good sense where that sound came from. When you hear something in two ears, your brain figures out the minute differences in when the sound arrives and determines where the sound is coming from,” explained Dr. Mark Halpern, a professor in the Department of Physics and Astronomy at the University of B.C. 

“All it takes is having that second ear. It doesn’t have to be that big.”

Even with the second telescope nearly 100 kilometers away, though, the CHIME team only expects to be able to narrow down a signal’s source to a particular galaxy, said Halpern.  (Our own galaxy, the Milky Way, is estimated to be a billion billion kilometres across.)

Still, that will be a feat akin to seeing individual people in a photo of Vancouver taken with a camera in Penticton.

Halpern on behalf of the CHIME team has applied to the Regional District of Okanagan-Similkameen for a temporary use permit to allow construction of the second telescope on land leased from Copper Creek Ranch.

A public information session is set for Aug. 17 and will be staged by videoconference to allow people a chance to find out more about the application, which will ultimately require approval from the RDOS board.

If all goes according to plan, the new telescope could be built by this winter, said Halpern.

His team’s search for fast radio bursts began in 2017, when the switch was flipped on the original CHIME telescope at the Dominion Radio Astrophysical Observatory, which is about a 20-minute drive south of Penticton.

Radio waves are focused by the wire mesh over the steel frames, and the torrent of information is then sent to a super-computer that can complete seven quadrillion calculations per second.

The computer sifts through the data for signatures of fast radio bursts, which are high-energy pulses lasting just 1/1000th of a second and believed to be emanating from massive stars in deep space. Once a fast radio burst is detected, the computers alerts astronomers, who then try to verify it and figure out what produced it.

To date, CHIME has recorded more than 1,000 such signals, which were only detected for the first time in 2007. If a pulse’s origin is known, the data it contains can then be used to extrapolate things like the density of space through which it travelled.

The telescope’s other major area of inquiry is dark energy.

Dark energy was discovered in the 1990s and is believed to account for 70% of the energy in the 13-billion-year-old universe. It’s also believed to be driving the ever-accelerating expansion of the universe, but what gives rise to the force is unknown.

The CHIME telescope can investigate dark energy by observing radio emissions from clouds of hydrogen to measure the expansion of the universe between seven and 11 billion years ago, when dark energy first began exerting itself.

None of it would be possible, though, without the unique environment in the White Lake basin that protects the observatory from light pollution and radio interference. The RDOS in 2018 passed bylaw amendments to keep it that way.

“It’s really worth saying that with the observatory at White Lake, the Penticton area is a very special place for us,” said Halpern.

“It’s a special place in the whole world.”

The CHIME telescope was designed and built by scientists from the University of British Columbia, McGill University, the University of Toronto, the Perimeter Institute for Theoretical Physics and the National Research Council of Canada. Collaborating partners include the Massachusetts Institute of Technology and Yale University.

This article has been updated to correct the sizes of the two telescopes and clarify some other information