Laser shoots
asteroids off course
Asteroids could destroy all life on Earth, but scientists
are working on a defence craft that could shoot asteroids
off course by means of laser light.A major battle with laser guns
took place outside Bond
villain Drax’s space station,
from where he aimed to kill all
humans on Earth. But in the real
world lasers could one day become
mankind's saviour from the 20,000+
near-Earth objects – comets and
asteroids – that orbit the Sun and
might collide with Earth. NASA has
named objects with diameters over
140m as “potentially dangerous”rocks that could destroy all life in
entire cities or regions if they strike.
Scientists from the University of
California aim to avoid such major
strikes by means of laser guns
mounted on ion-powered spacecraft. If
astronomers spot an asteroid heading
towards Earth, a craft would be
launched so its lasers can shoot at the
asteroid. With 19 laser guns hitting
the same spot on the asteroid, its
surface would heat to 2700°C, hotenough to sublimate rock and metal
directly from solid state to gas. The
flow of rock and metal away from the
surface would push the asteroid in the
opposite direction, altering its course
sufficiently to make sure that the
asteroid flies past Earth. Thanks Drax!VILLAIN
The (^) villain Hugo
Drax in Moonraker
( (^1979) ) aimed to kill all
humans on Earth from
his space station. Nasty!
Spacecraft follows asteroid
1 The DE-STARLITE spacecraft will be launched into space as soon as
astronomers on Earth spot a potentially
harmful asteroid. The craft follows the
asteroid at a distance, so its laser gun is
constantly aimed directly at the asteroid.
Laser shoots from 10km
2 The laser gun fires 19 1-3kW laser beams. The beams travel 10km
through space before they all hit an
asteroid at one spot with a 10cm diameter.
The light heats the asteroid’s surface to
approximately 2700°C.
Gas pushes asteroid away
3 The heat makes rock and metals go from a solid state to gas. The gases
move away from the surface, pushing the
asteroid in the opposite direction –
like a rocket caused to move forwards
by a beam of fuel fired backwards.
Asteroid
Rock
DE-STARLITE Laser beams
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