AIM satellite studying noctilucent clouds, artwork. AIM (Aeronomy of Ice in the Mesosphere) was launched on 25th April 2007 to study noctilucent clouds. Here the SOFIE (Solar Occultation For Ice Experiment) instrument is looking through a cloud at the Sun, allowing the cloud's temperature and composition to be measured. Noctilucent clouds are the highest altitude clouds known in the atmosphere, forming some 80 kilometres above Earth's surface. Little is known about the factors that influence their formation and development, and it is hoped that AIM will provide much more information about them. The clouds have increased in prevalence and brightness in recent years, which some suggest is related to climate change.