Astronomers learning about the Universe need telescopes that capture different parts of the electromagnetic spectrum – using just one wavelength would exclude large parts of the information available to us – rather like watching the 3D, high definition version of Avatar on an old black-and-white television. With the sound off. As well as building different types of telescopes, we’re also pushing the boundaries on sensitivity, pixel count and speed for the detectors, so that new facilities are built with a state-of-the-art view of what’s beyond our atmosphere.
Autumn 2013 saw the final radio telescope being put in place for ALMA, the Atacama Large Millimetre/ Sub-millimetre array. In the high-altitude Atacama desert, 66 dishes give ALMA an effective diameter of 16 kilometres. STFC provided equipment and software to help ALMA probe the mysteries of the early Universe (just after the Big Bang), and UK industry secured over £5 million of contracts during the construction phase. ALMA gives us an extremely clear view of the enigmatic cold regions of the Universe, including the relic radiation left by the Big Bang, and to see beyond obscuring dust to the earliest and most distant galaxies.
The GAIA spacecraft is due to launch in December 2013. It combines two optical telescopes with a 1-gigapixel digital camera, and its mission is to make a highly-detailed, 3D map of the Milky Way. Over the next five years, it will generate images of over a billion stars, brown dwarfs and exoplanets. Looking at each object multiple times will also show us their motion, and any changes in their brightness. GAIA is also expected to find hundreds of thousands of new objects in our galaxy, and will also be taking a look at around 500,000 distant quasars – data that will be used to put Einstein’s General Theory of Relativity to the test.
Looking forward, we’re working on the James Webb Space Telescope, which is scheduled for launch in 2018. STFC supported and led the construction of an IR (infrared) instrument (MIRI) that will play a key role in the telescope’s mission to look for the first galaxies that ever formed, and to search for signs of extra-terrestrial life on distant exoplanets. Using IR allows us to see warm objects hidden behind dust clouds, such as the first stars formed in the Universe, and stars that are in the process of forming planets.
The Very Large Telescope (VLT), at the ESO Paranal Observatory in Chile, is the world’s most advanced optical instrument. It has four 8.2 metre diameter mirrors, plus four 1.8 metre movable auxiliary telescopes. The telescopes can be used individually, or combined into a giant interferometer. The VLT helps to make ESO one of the world’s most productive observatories, looking at the faintest and most remote objects in the Universe (it took the first image of an extrasolar planet). UK astronomers can access the VLT via our ESO membership, and STFC supported construction of the KMOS (K-band Multi-object Spectrometer).
And we’re planning for the future with E-ELT, the European Extremely Large Telescope, which will be the largest optical telescope on Earth and will also have near IR capabilities. E-ELT will be able to capture 13 times more light than the largest optical telescopes have at the moment, and to generate images 16 times sharper than those produced by the Hubble Space Telescope. UK industry has already won £9 million of contracts on this project.
All of this star-gazing doesn’t only give us a good view of the Universe – telescope technology brings everyday benefits here on Earth as well. High performance optical and infrared detectors have a wide range of applications, including biomedical imaging and security scanning. Techniques developed to process the vast amounts of data from telescopes are being used to stabilise MRI images of moving patients, which means young children can be scanned without being sedated. And if it weren’t for telescopes, you probably wouldn’t be reading this now – WiFi originated in the search for radio signals from exploding black holes!
Astronomy has a big, bright future – now that we can see the Universe in all its light.