Viva Brighton Issue #59 January 2018

ASTRONOMY
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Dark Energy Survey
Mapping deep space
It’s a clear, dark night. Look up. What do you see?
Twinkling stars? The moon? An orbiting satellite?
Now imagine that your eyes have become superhuman
and that you are looking across space and time
to witness every galaxy that has ever been formed
during the 14-billion-year history of the Universe.
This is the ambition of Kathy Romer, a University
of Sussex Professor of Astrophysics and Director
of the Sussex Astronomy Centre who, together
with collaborators in the international Dark Energy
Survey (DES) project, is mapping deep space
with the aid of powerful telescopes.
Dark energy is an unseen and mysterious phenomenon
that fills the gaps between the physical
matter in the Universe. Various theories abound
as to its purpose and existence, but its most alarming
property is that it is causing the Universe to
expand at an ever-increasing speed.
“It’s scary,” says Kathy. “Taken at face value, dark
energy will eventually rip the Universe apart. So
it is vital that we throw everything we’ve got at
it – telescopes, supercomputers, mathematics - to
understand it better.”
Kathy, who has been involved with the DES project
for more than a decade, is helping to gather and
analyse data via the Victor M Blanco Telescope in
Chile. From August to February a 570-Megapixel
digital camera mounted to the telescope captures
information from 300 million galaxies that are
billions of light years away from Earth.
“With DES, we are not only able to trace how the
Universe has evolved in the past, we can now predict
how it will behave in the future,” says Kathy.
“But even DES can’t probe cosmic evolution in
real time. For that we don’t just need static maps,
we need movies.”
This will be possible when a new telescope,
the Large Synoptic Survey Telescope, starts
operating in Chile in 2020. It will map and make
movies of the whole southern skies every few
days, detecting the movement of millions of
phenomena in deep space.
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