Breakthrough in search for ET as scientists develop method to see whether planets orbiting distant stars could harbour life New technique can penetrate the dazzling light of distant stars Instruments were previously blinded by light while trying to see planets Scientists able to discern the 'chemical fingerprints' of the atmospheres of five planets 128 light years away Astronomers today claimed to be a step closer to discovering alien life thanks to a new technique which allows them to make a remote reconnaissance of distant planets. A project by researchers at Cambridge University has harnessed new software and instruments to collect the first chemical fingerprints of planets orbiting a star 128 light years away from Earth. Previous techniques had only managed partial measurements of the system's outermost planet before light from the star itself blinded the instruments. Dazzling: After applying several advanced optical techniques the P1640 camera sees only a very small fraction of the light from HR8799 in this 'speckle' pattern. The images of the four planets are still hidden While the planets proved 'too toxic and hot' for life as we know, study co-author Ian Parry said the techniques could one day give us the 'first secure evidence of life on a planet outside our solar system'. The central star that the planets orbit, known as HR 8799, is five times brighter and produces about 1,000 times more ultraviolet light than the Sun. In the past it has meant that the blinding starlight - tens of millions to billions of times brighter than the reflected light of the planets - has restricted how far astronomers can see. Now, for the first time, scientists have been able to penetrate the starlight to read the unique light signatures of the chemical elements that make up the atmospheres of the four planets. Project 1640, a collaboration between Cambridge academics and researchers from several U.S. institutions, used the Hale telescope at the Palomar Observatory in California. Previously light from bright distant stars had so dazzled telescopes that it had been imposssible to clearly see planets orbiting them. But, the scientists say, the new capabilities developed for Project 1640 allow for the rapid characterisation of exoplanets, giving information about their atmospheres and surface temperatures. After using advanced software techniques the speckle pattern can be removed and the images of the 4 planets are revealed (labelled b-e). P1640 takes 30 pictures like this simultaneously with each one at a different wavelength (i.e. colour) so that a spectrum is measured for each planet Ben Oppenheimer, of the American Museum of Natural History, said the new ability to go beyond starlight to read exoplanet atmospheres was like 'taking a single picture of the Empire State Building from an airplane that reveals the height of the building but also a bump on the sidewalk next to it that's as high as a couple of bacteria'. Astronomers are developing a system to use reflected starlight to create maps of alien planets that show oceans, land and even clouds. Developed by planetary scientist Nicolas Cowan and presented at a meeting of the American Astronomical Society in January, it is inspired by a technique previously used by military spy satellites. The software can take a point of reflected starlight from an exoplanet, and analyse it to extract the unique signals required to form a rough map. Because there is currently no telescope powerful enough to directly photograph a faraway rocky planet, Dr Cowan tested the software on images of Earth taken from a distant vantage point in space by Nasa's Deep Impact spacecraft as part of the EPOXI mission. 'The object of this experiment was to see whether we could identify the colours of surfaces on Earth, [and tell] how many major surfaces are there, and what they look like,' said Dr Cowan, who works at Northwestern University in Evanston, Illinois. Project 1640 does this by sharpening and darkening a star's light. This technical advance involves the coordination of four major instruments - including the world's most advanced "adaptive optics" system, which can make millions of tiny adjustments every second to it's internal mirrors for optimal imaging. These techniques can reveal planets one to even ten million times fainter than the star at the centre of the image, after only an hour of observation. Scientists have described some of the results from this initial study as 'quite strange', as the exoplanets are 'redder', emitting longer wavelengths of light, than celestial objects with similar temperatures. They say the observed phenomenon could be explained by significant but patchy cloud cover on the planets. There is also an intriguing chemical imbalance in that the planets contain either ammonia or methane, but not both, running counter to basic laws of chemistry given the atmospheric temperatures. These bizarre observations could be down to the brightness and huge amount of UV light shone by HR 8799, the star at the centre of the system, which could affect the chemical "spectra" of the planets, possibly causing complex weather such as dense carbon fog, the researchers said. They are already collecting more data on this system to look for changes in the planets over time, as well as surveying other young stars. During its three-year survey at Palomar, which started in June, Project 1640 aims to survey 200 stars within about 150 light years of our solar system. A detailed description of the study is due to be published in The Astrophysical Journal.