Even on the starriest of nights, the
human eye sees just a tiny fraction of the
cosmos. So if the curve of the Big Dipper
or the four points of the Southern Cross
appear magnificent, consider how many
more phenomena must exist out of view.
That prospect is what led astrono-
mer Natasha Hurley-Walker to a radio
telescope deep in the outback of West-
ern Australia. The telescope, called the
Murchison Widefield Array, is made
up of thousands of antennas that see
through celestial dust and detect “radio
light”—revealing colors and objects in
a spectrum not visible to humans, even
with the aid of optical telescopes like
Hubble. Stretched across nearly four
square miles of desert, the antennas—
cheaper to produce and maintain than
typical dishes—look like “an army of
mechanical spiders,” she says.
In the past four years, Hurley-Walker
and a team of researchers—from the In-
ternational Centre for Radio AstronomyResearch in Perth as well as other insti-
tutions in Australia and New Zealand —
have stitched together more than 40,
images taken by the telescope.
The result is a groundbreaking por-
trait of the entire southern sky. It exposes
hundreds of thousands of galaxies mil-
lions of light-years away. And it shows
in unobscured, blazing color the radio
glow of the Milky Way, lit up with the
remains of exploded stars and intense
magnetic fields. This sweeping survey,
says Hurley-Walker, “allows people to
see the sky with radio eyes.”
Her research is far from finished.
Hurley- Walker is now working with an
international team to develop a radio
telescope many times bigger and more
sensitive than the Murchison Widefield
Array. Its technology could pick up faint-
er signals, which would unveil millions
more galaxies and—if her wish comes
true—“the birth of the very first stars.”ARRAY OF LIGHT
By Catherine ZuckermanEXPLORE
SPACE
GAMMA RAY X-RAY VISIBLE
In this composite image, the Milky Way
and radio galaxy Centaurus A glow in
the southern night sky above a section of
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Below, the center of the Milky Way is
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