20 ASTRONOMY • FEBRUARY 2018
These bright
but f leeting
explosions
unleash more
energy than the
Sun produces in
a day — and yet
we don’t even
know what
causes them.
by Yvette Cendes
The mystery of
fast radio bursts
uncan Lorimer says he will
never forget the day in 2007
when he stumbled upon
the first bolt from the blue.
The West Virginia University
astronomer had tasked an undergraduate
student, David Narkovic, with combing
through pulsar survey data from Parkes
Observatory in Australia, and one day
Narkovic walked into Lorimer’s office with
an unusual signal unlike anything anyone
had seen or predicted before. It was one of
the brightest astronomical sources in the
sky for a scant few milliseconds, and it bore
signatures of an origin beyond the galaxy.
“I was stunned,” recalls Lorimer. “Frankly, I
didn’t know what to make of it.”
Lorimer had discovered the first fast
radio burst, or FRB. He published his find
later that year. At first, no one else in
the astronomical communityknew what to make of it, either. Surely
such a signal was some sort of man-made
interference, many argued, or some
phenomenon like lightning. Researchers
even produced evidence of man-made
signals that looked similar to Lorimer’s FRB
but were in fact created by a microwave
oven at Parkes. “Even my own wife [radio
astronomer Maura McLaughlin] was on a
paper arguing the first burst wasn’t real,”
recalls Lorimer.A powerful outburst builds along the surface of a
magnetar. The atmosphere and crust of these objects
are coupled magnetically. Rapid release of energy
can fracture the crust, leading to a starquake and
potentially producing a burst of radio energy:
a fast radio burst. DON DIXON FOR ASTRONOMY