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were published, many of which were
quickly discarded when a newly discovered
GRB didn’t fit the bill. In the end, however,
this was hasty because it turns out GRBs
from deep space fall into two major catego-
ries (and a few more rare ones). About
70 percent of all GRBs are so-called long
GRBs, which occur when a supermassive
star at the end of its life explodes as a super-
nova and subsequently forms a new black
hole. The remaining category is made up of
short GRBs, which originate when two neu-
tron stars merge. These were confirmed in
October 2017 by the gravitational wave
detector LIGO and telescope follow-up.
The moral of GRBs is no single theory
can cover all angles of their origin. Many
astronomers therefore argue one should be
cautious to assume all FRBs are from the
same sources.

Aiming for answers
It is clear to many astronomers that find-
ing more FRBs is the key to decoding
their secrets. “Every FRB right now is
like an individual snowflake, where we
admire the individual characteristics and
details we can see,” explains Emily Petroff,
an American astronomer at ASTRON,
the Netherlands Institute for Radio
Astronomy. Petroff has discovered several
FRBs and created the first-ever catalog for
the signals. “In the future, we want an FRB
snowbank, where there are so many FRBs

you no longer care about an individual

one,” she says.

Many groups are interested in contrib-

uting to that FRB snowbank, with new

instruments and telescopes under develop-

ment to search for them. One of the stand-

outs is the Canadian Hydrogen Intensity

Mapping Experiment (CHIME), predicted

to spot as many as several dozen FRB sig-

nals each day. As the name implies,

CHIME was not initially conceived as an

FRB-detecting machine — its primary sci-

ence goal is to precisely map hydrogen in

distant galaxies to learn about the expan-

sion history and acceleration of the uni-

verse. But it does have an ideal field of view

for FRB hunting, and when Victoria Kaspi

of McGill University heard about the first

FRBs, she acquired funding to look for

them as well. “I was first thinking about

pulsars,” Kaspi confesses, “but it soon

became clear that CHIME would be ideal

for FRBs.”

Ten years after discovering the first

FRB, Lorimer is optimistic about the

future. He predicts that by 2020, the first

hundred FRBs will be found thanks to

CHIME, and by 2025, thousands of FRBs

will be known with many radio telescopes

around the world searching for them. He

even speculates that by 2030, FRBs could

be essential cosmological tools, taking

advantage of the vast distances they travel

to probe distant parts of the universe.

We are at the dawn of the fast radio burst

era. For now, we will have to wait to see

where this new cosmic mystery takes us.

Yvette Cendes is a radio astronomer at the Dunlap

Institute for Astronomy and Astrophysics, University

of Toronto. Her website is http://www.yvettecendes.com.

The complex Crab Nebula contains the Crab Pulsar, which formed in a supernova recorded in A.D. 1054.

In addition to regular pulses, the pulsar emits occasional strong nanosecond bursts. If even younger

neutron stars generate stronger, shorter bursts than the Crab, they might be seen as FRBs. ESO

The first identified FRB, FRB 010724, lasted less than 5 milliseconds. This observation of FRB 010724,
taken with the 13-beam receiver of the Parkes radio telescope, shows flux in beam 07 as a function of
time. It appeared in data taken in 2001 but was not discovered and published until 2007. DUNCAN LORIMER

A curious signal