Space
Climate satelliteFrom its lonely vantage point in space,
CryoSat is giving scientists the picture
of what’s happening to polar sea ice.
Now the race is on to build a follow-on
mission before it runs out of steam
n 1957, the Soviet Union encountered a frosty
reception when it launched the first artificial
Earth satellite, Sputnik 1, at the height of the
Cold War. The move sparked the Space Race
and led to fears that these man-made eyes-in-the-sky could
be used as weapons and spy tools. But our relationship with
satellites has thawed significantly in the 60 years since. Vital
for communication, navigation and science, they connect
remote regions, help us get from A to B, and enable us to
make fascinating discoveries about the universe.
So meet CryoSat, a satellite that orbits the Earth at an
altitude of just over 700km. Launched from Kazakhstan on
8 April 2010 by the European Space Agency (ESA), the 720kg
watchdog was welcomed by climate scientists monitoring
changes to Earth’s polar ice sheets. It provides an early
warning of the impact of rising global temperatures by
measuring the fluctuating thickness of ice floes in the ocean
and monitoring land ice in Antarctica and Greenland.
‘The ice that’s on land is important to sea-level rise whereas
the ice at sea is important because of the albedo effect,’
says Andrew Shepherd, professor of earth observation at
the University of Leeds, referring to how ice reflects the
sun’s energy back into space. ‘If there isn’t any sea ice, the
Earth gets warmer.’ Thickness measurements from CryoSat,
I
A satellite view of
plankton in the
Arctic Ocean