Monday, February 17, 2014

Things that boggle my mind

People (as we would recognise ourselves) have been around on this planet for quite a decent period of time, certainly in the order of a quarter of a million years or so; we invented agriculture around 10,000 years ago and started to develop organised societies with cities, systems of government, religions and writing some 5,000 years ago; the Romans rose up around 2100 years ago and disappeared a few hundred years later. 500 years ago printing was invented and as early as 300 years ago we were making maps of the night sky using early optical telescopes. We had the beginnings of what was necessary to truly understand our place in the universe and a mechanism to communicate it widely. It took another 200 years to grasp the true size and scale of our cosmic back-yard and throughout the Enlightenment as we discarded our primitive paranoia about magic deities in the sky who governed our thoughts, we've been improving our knowledge at an ever increasing rate.

This year we have a brand new European space craft in an L2 orbit 1.5 million km from the Earth called Gaia. The two tonne space-craft will remain in orbit for 5 years mapping around 1% of the 100 billion stars in our galaxy with an unprecedented degree of precision. The camera on board the ESA Gaia platform has around 1 billion pixels, that's a lot of pixels! It can resolve objects to 1/3600th of a degree, which is equivalent to resolving a mobile phone on the surface of the Moon and is several thousand times what the Hubble space telescope can do. Over the years Gaia will measure the change in positions of the stars as well as their apparent motion as the Earth moves around the Sun (parallax) it will also look at what the stars are made of via their electromagnetic spectra as well as their Doppler shift which tells us their precise motion through space. The data should enable us to understand our place in the universe much better than before and who knows, just like the early star charts, this data may be used by some future explorer as a navigation aid on some pioneering cosmic voyage, I wonder if I'll still be around to see it.

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