Meet Gaia, a rather special satellite, and
what's been dubbed one of the most ambitious
space missions in history. Gaia, a product
of over 50 companies led by Astrium satellites
of France, blasted off from French Guiana
on Friday and is now hurtling to a point 1.5
million kilometres from Earth. From where
it will map over a billion stars. The spacecraft
is set to create a 3D picture of the milky
way, for the first time locating and distancing
with pinpoint accuracy countless stars, planets
and the objects in between. Assuming it works
once it's up there, Gaia is good. It's taken
over 20 years of development and 740 million
Euros to develop, and is believed to be one
of the most sensitive pieces of machinery
ever constructed.
On board the craft, two telescopes will shine
light onto a one billion pixel camera sensor
and a trio of instruments. By scanning repeatedly
over five years, Gaia will be able to pinpoint
the brightest stars to an accuracy of seven
micro-arc seconds. That's like looking at
a euro-cent coin on the moon. From Earth.
The craft will also plot the direction and
velocity of some 150 million of the stars
it scans, we'll also be getting a reverse-engineerable
picture of how the milky way formed, and what
it'll look like in future. So sensitive is
the camera, it will be able to spot planets
orbiting stars, comets, asteroids, cold, dead
stars and even brown dwarfs, which up to now
have been remarkably hard to spot. It's estimated
that by the end of the decade, Gaia will have
produced over a petabyte - 200,000 DVD's,
of information that will quite literally transform
our understanding of the cosmos.
