Scientists have proposed a new way to look for aliens: spotting the waste heat they emit, New Scientist reports. Normally, a galaxy gives off about 10% of its light in the midinfrared range. Those that emit much more midinfrared light could be going through prosaic processes such as rapid star formation—or they could be harboring alien civilizations with vast networks of heat-generating technology. Using images generated by the Wide-field Infrared Survey Explorer, researchers have found several dozen potential candidates, the team reports in The Astrophysical Journal. Next, the team will examine the candidates to rule out false positives.