Do you think about satellites often?
Perhaps you should. Satellites, either man made or natural, are what allow us to live life as we know it. Without the moon, there would be no tides; the Earth’s orbit, without the gravitational influence of this changeable companion, would not be stable over long timescales, and we wouldn’t have the (mostly) regular climate which allows for our survival.
In the European Space Astronomy Centre (ESAC), which our Year 12 physicists had a chance to visit last week, satellites of all kinds are just one of researchers’ tools for observing the Universe, and in the shadows, holding together the pieces of all the technology you see around you.
The ESAC facilities are located just outside of Madrid, off the edge of a residential area which trails off into a verdant forest. Driving up to it, there was already a certain degree of expectation; the closer the bus got, the more massive the satellite dishes alongside the road seemed to become. Full sized radio telescopes (not dissimilar to the one our own Gonçalo Fernández-Nespral replicated in a smaller scale) stood pointed at the sky, and the centre seemed to be in growing isolation as we approached it, a step away from the small residential area we were leaving into the unknown.
At the gate you’re greeted by a reconstruction of the Gaia mission, tasked with producing a three dimensional map of our galaxy, the milky way. This is a common theme around the ESAC centre: at every juncture in the roads there seems to be a scaled down model of old satellites, obsolete projects, which bring a glint to the centre researchers’ eyes; even of a few current endeavours— which light a spark of pride in those explaining them.
The visit itself consisted of two activities— an introduction to emission spectra and how they can be used to determine the identity and thus, composition, of stars; and a tour of the facilities and the models of old missions, culminating in an explanation of the functioning of a large radio telescope.
More interesting perhaps than the workshop itself, was the breadth of research and of activities conducted at the ESAC. We were greeted by three scientists, two highly intelligent women, who spoke clearly and confidently about what they did, and an eccentric German professor, who answered a few questions we had prepared for them.
We learned that while they deal with the more exotic sides of space exploration, what one would generally imagine: looking at the stars, comets and other phenomenons of the sort: the ESACs lesser known, but primary function is that of a data processing facility: they look at information transmitted by satellites, decipher it, and send it to their respective locations. At the moment, they are facing a Chinese information satellite and dealing with that data, however depending on which satellite is facing them in orbit, that is the information they receive.
Satellites are responsible for GPS, space imaging and a vast array of other things; even the internet, on which you might be reading this article right now. We have the ESAC and their collaborators to thank for that.
Beatriz J, Year 12