A Telescope Unlike Any Other
The Canadian Hydrogen Intensity Mapping Experiment, or CHIME, is a revolutionary radio telescope. Instead of a familiar large dish that pivots to track stars, CHIME consists of four stationary, 100-metre-long cylindrical reflectors. This unique design
allows it to stare at a huge patch of the sky at once. As the Earth rotates, CHIME scans the entire northern sky every single day. What it lacks in moving parts, it makes up for with immense digital power. Built with components adapted from the mobile phone industry, its supercomputers process an amount of data comparable to the world's entire mobile data network traffic. This design makes it a powerful and affordable tool for scanning the cosmos.
Mapping the Universe to Understand Dark Energy
CHIME's primary mission is one of the most ambitious in modern physics: to solve the mystery of dark energy. Scientists know the universe is not only expanding, but its expansion is accelerating, driven by this unknown force that makes up about 70% of the cosmos. To investigate this, CHIME is creating the largest-ever three-dimensional map of the universe. It does this by detecting the faint radio signals from neutral hydrogen, the most abundant element in space. By mapping the distribution of this hydrogen from a time when the universe was between 2.5 and 7 billion years old, CHIME can measure the history of cosmic expansion with incredible precision. This provides a 'standard ruler' to chart how dark energy has behaved over billions of years.
An Unexpected Role: The Ultimate FRB Hunter
While designed for cosmology, CHIME's wide view and sensitivity made it unexpectedly perfect for something else: detecting Fast Radio Bursts (FRBs). These are incredibly powerful, millisecond-long bursts of radio waves from deep space. Their origin is one of the biggest puzzles in astronomy. Before CHIME, only a few dozen FRBs had ever been found. Since it began operations, CHIME has become the world's leading FRB detector, discovering thousands of these enigmatic signals and transforming the field. It even detected the first FRB known to originate from within our own Milky Way galaxy, linking at least some of these events to highly magnetized neutron stars called magnetars.
Recent Breakthroughs and Future Promise
Recently, the CHIME team announced a major milestone: for the first time, it detected the faint glow of hydrogen from billions of years ago using only its own data, without needing to cross-reference with other telescopes. This proves its 'intensity mapping' technique is a powerful, independent method for studying dark energy. Furthermore, by adding smaller 'outrigger' telescopes across North America, CHIME can now pinpoint the precise locations of FRBs. This has already led to stunning discoveries, including tracing a burst to a surprising location in an old, dead galaxy where the suspected source—a young star remnant—should not exist. These findings challenge existing theories and open up new avenues for research.
