 ASCAP is a radio telescope that we're building in Western Australia. It's a new generation of radio telescope which will be able to survey the whole sky to great depths. And what we want to find out is how do galaxies evolve over time. So the data comes off the telescope in raw form and gets transmitted via optical fiber to the supercomputer center in Perth. At that point the data gets processed and it gets converted into images of the sky. And those images will be made available to astronomers worldwide. With ASCAP the data volumes are truly enormous and so to make it easier to archive it and also to make it easier for the astronomers who are going to use it the data was actually processed quite a lot before it gets to be archived. So that raises a new paradigm in a sense if you want to be very sure that your data quality is very good before you do archive it. So the great thing about archives is that you put the data in a central location and then anybody can get it from there. The best way to get return on the investment of this big telescope was to have completely open access data policy. There were two reasons we did this. One is because of the internationalization of astronomy generally. The sky is up there for anybody to look at. The second reason was we've got these big teams set up who know the projects they want to do. It's important to keep them honest. It's important that they publish and do the stuff with the data they've got. They can't just leave it languishing for 10 years and then oh yes well maybe I'll do something with data now. They can't do that anymore because the data is freely available to anybody and somebody might nip in and steal their idea. Open data I think is really crucial to getting the best science from your telescope. We're building a very expensive telescope and it's important that the best science gets done. So let's say for example I have a really good idea for a science project and I want to look at this patch of sky over here. I go away and I look at it and I do my own thing. Then the data sits in the archive and somebody from somewhere else might have another completely different idea to do with the same data patch. They will go away, extract the data from the archive, have a look at it, do their own clever science and publish something completely different. So there for the same observation you've got two pieces of clever science. One piece that the original person never even thought of and so that's the really great advantage in having open access data. The questions that it can answer are maybe questions that you haven't even thought of yet and that's I think the beauty of a data archive. So I can carry out an experiment to do what I want to do because I've had that idea. But then maybe in the future science always moves on and there's always different things to do. So in the future somebody will have a completely different question that I haven't thought of and they can use that data to answer their question. They don't need to go back and take expensive telescope time, they can just look at the data that exists already to help answer their questions.