Ancient Fast Radio Burst Detected From Galaxy Just 3 Billion Years After Big Bang

In a study published in Science, Manisha Caleb and colleagues announced the discovery of FRB 20240304B, the most ancient fast radio burst recorded to date. The burst was first detected in 2024 by South Africa’s MeerKAT array and exhibited an unusually high dispersion measure of about 2,400, implying a travel time of roughly 10 billion years. Follow-up observations with the James Webb Space Telescope pinpointed the origin to a compact dwarf galaxy that existed only 3 billion years after the big bang, far earlier than the formation of the Sun and Earth.

The millisecond-long flash released as much energy as the Sun emits over several days. While the exact mechanism remains uncertain, Ryan Shannon suggested magnetars as one possible source. The researchers argue that such distant FRBs could serve as probes of the cosmic web, offering new insight into the distribution of ordinary matter across the universe.