Gaia: The ‘impossible space mission’ ready to fly (BBC, 21 Aug 2013)

 

Newspaper: BBC

Tittle: “Gaia: The ‘impossible space mission’ ready to fly”

Webpage: http://www.bbc.co.uk/news/science-environment-23779294

Publication date: 21 August 2013

“It blows your brain. I remember when we went and asked for this stuff we just fell about laughing. We said: ‘Well, let’s try; let’s see what happens. These engineers are smart’. And, boy, they’re smart – they did it!”

Cambridge University’s Gerry Gilmore says astronomers thought they were requesting the impossible when the spec was put forward in the early 1990s for a space mission to make a far-reaching census of the Milky Way.

The desire was to map very precisely the position, motion and properties of hundreds of thousands of the brightest stars all the way to the galactic centre and beyond.

If that could be achieved, the scientists argued, we could unlock remarkable information about the structure and history of our corner of the Universe.

Today, this mission impossible is built and ready to go.

On Friday, the European Space Agency’s Gaia telescope will be flown to French Guiana to begin the preparations for launch on a Soyuz rocket in mid-November.

The satellite is going to make the ultimate map of the sky. For certain, its catalogues will underpin pretty much all of astronomy for decades to come.

Gaia will pinpoint about a billion stars and build a profile on each and every one, including:

  • exact coordinates, including distance
  • brightness – temperature
  • composition
  • age, and so on.

And for about 150 million of these stars, the telescope will determine their velocity not merely across the sky but their movement either towards or away from us.

It’s this part that blows my brain, because these three-dimensional markers then allow us to trace the evolution of the Milky Way, long into the future and deep into the past.

“It will be a time-lapse movie and we’re going to watch it,” says Prof Gilmore.

“We will see the remnants, the debris streams, of the first shards that became what is today the Milky Way. We can run the process right back to the first things that ever happened. We will see the entire history of the Milky Way unfolding before our eyes.

Read more: http://www.bbc.co.uk/news/science-environment-23779294