1.3.2 Behind the scenes with Gaia
The Open University’s Department of Physical Sciences is involved in many different research projects, one of which is the Gaia satellite.
Ross Burgon is one of the scientists working with the Gaia project team. In the following video he talks to Phillipa about the research carried out in the Centre for Electronic Imaging (CEI) [Tip: hold Ctrl and click a link to open it in a new tab. (Hide tip)] .
Download this video clip.Video player: ou_futurelearn_orion_vid_1027.mp4
Transcript
PHILLIPA SMITH:
I’m here with Dr Ross Burgon at the Centre for Electronic Imaging and The Open University. And he’s going to tell me all about the Gaia Mission. Ross, what is Gaia?
ROSS BURGON:
Gaia is a European Space Agency space telescope, ultimately. And it was launched in December of 2013. And it’s on a five-year mission in order to map a billion stars in the Milky Way Galaxy.
PHILLIPA SMITH:
What’s been your involvement in the Gaia mission?
ROSS BURGON:
At The Open University, we are involved in a number of different ways. We looked at the CCD imaging sensors to see how they operate in the environment in space. We also designed some of the software which analyses the data from the spacecraft. And we’re also involved in the science alert followup side of the mission as well.
PHILLIPA SMITH:
Could you tell me a little more about the detectors?
ROSS BURGON:
This is a Gaia CCD. A CCD is an imaging sensor which converts light into electrical signal which we can then display on our computer screens. This sensor is about nine megapixels, so it’s slightly larger than the type you would find in your digital camera. However, Gaia itself has 106 of these detectors. You can see at the back here a one-to-one scale of the Gaia focal plane. 106 of these detectors means that the camera itself is about a billion pixels.
PHILLIPA SMITH:
What makes Gaia different to other space missions?
ROSS BURGON:
OK. So Gaia is quite different to most space telescopes. A space telescope like Hubble will stare at the sky for a very long period of time and will create those beautiful images which NASA and ESA release on quite a regular basis. Gaia is actually scanning the sky, which means that it’s very slowly rotating. So it takes about a minute for a star to pass across the entire focal plane of the camera. This means that it doesn’t have the time to build up those wonderful pictures. So for Gaia, we’re not going to see pretty pictures. What we will get, however, is a detection of the positions of the stars down to an accuracy which has never been recorded before.
PHILLIPA SMITH:
What can we learn from the Gaia mission?
ROSS BURGON:
The key thing about Gaia is that it is accurately mapping the positions of the stars. So accurately, in fact, that if Gaia was on the Earth, you would be able to resolve a one pound coin from the surface of the moon. What this allows us to do, then, is not only map the positions of the stars, which gives us a static view of the Milky Way, but we can also investigate the velocity of the stars as well, so how the stars are moving through the Milky Way. And with our understanding of gravity, then we are able to take that five-year snapshot of position velocity. We are able to rewind the galaxy. So we can see what the galaxy looked like in the distant past. And also, we’re able to forward wind the galaxy as well and see how the galaxy is going to evolve in the future.
PHILLIPA SMITH:
To find out more about the Gaia mission or other research at the Centre of Electronic Imaging, please follow the links on the screen.
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Next, you’ll have an opportunity to test your knowledge in the end-of-week quiz.