Astronomers fromthe European Space Agencyâs Gaia missionwill release the biggest map of our galaxy ever tomorrow, using data collected by the Gaia space telescope. That includes 1.7 billion stars, as well as new information that could potentially solve some cosmic mysteries. The ESAâs Gaia telescope launched in 2013 and soon after began its galaxy-mapping mission. Back in 2016, it released position and brightness data for 1.