What do you need to map a billion stars ? A billion-pixel camera certainly helps . Scientists hope to glean more clues about the origin and evolution of the universe , and in particular our own galaxy , after a camera of this incredible scale -- fitted to the Gaia space telescope -- was launched Thursday . Gaia , which lifted off from French Guiana , has been tasked with mapping the Milky Way in greater detail than ever before . Designed and built by Astrium for the European Space Agency ( ESA ) , the makers say the telescope is so sensitive that it could measure a person 's thumbnail from the Moon , or to put it another way , detect the width of a human hair from 1,000km ( 620 miles ) away . The mission 's aim is to build a three-dimensional picture of our galaxy , measuring precise distances to a billion stars . Even this is a small fraction of the Milky Way , as astronomers believe there are at least 100 billion stars in our galaxy . Tens of billions like Earth , study says . Astrium says Gaia is also expected to log a million quasars beyond the Milky Way , and a quarter of a million objects in our own solar system , including comets and asteroids . `` It can do it with incredible accuracy . It 's the biggest camera ever put into space , '' said Ralph Cordey , head of science and exploration at Astrium . He said the spacecraft cost 400 million euros ( $ 549 million ) to build , but the total cost of the mission would come to 740 million euros ( $ 1.02 billion ) when the expense of the launch and running the mission for its projected five-year lifetime are included . If successful , Gaia will add to the knowledge gained from NASA 's Hubble Space Telescope , which is still in operation , and ESA 's Hipparcos satellite , which gathered data until 1993 . Hubble spots azure planet where it may rain glass . The value of putting a billion-pixel camera into space has been championed by Robert Massey from the UK 's Royal Astronomical Society . `` Gaia is an amazingly ambitious mission , '' he said . `` Until now astronomers have relied on very indirect methods to gauge the distance to all but the nearest stars , meaning that the foundation on which we build a map of the universe is surprisingly weak . `` Building on the work of the pioneering Hipparcos satellite that mapped the stellar neighbourhood in the 1990s , Gaia will be used to carry out work analogous to the cartographers who surveyed the Earth in the 19th and 20th centuries , building up the first accurate charts of the cosmos and helping us better understand the structure , history and fate of the galaxy we live in . '' One of Gaia 's objectives is to help in the hunt for exoplanets -- new worlds beyond our own solar system . NASA 's Kepler mission has so far confirmed the existence of 167 exoplanets with hundreds more being investigated , but Cordey anticipates Gaia will likely discover thousands of new planets , while further missions will be able to uncover more detail about them . In a recent interview with CNN , George Whitesides , CEO of Virgin Galactic -- the company planning to take tourists into space -- said he thought that within a lifetime it would be possible to detect seasons on far-off worlds . He may have not have too long to wait , as Astrium is already working on design concepts to examine exoplanet atmospheres -- which may provide signs of seasonal variations . `` We are designing missions that could probably do that very thing -- it 's not science fiction , '' said Cordey . Read more : Cassini spots massive 'hexagon ' on Saturn .
European Space Agency 's Gaia has been tasked with making a 3D map of the Milky Way . Telescope so sensitive that makers say it could measure a human thumbnail from Moon . One of Gaia 's objectives is to help in hunt for exoplanets . Comment: