CO2 cloud on Mars

Credit by ESA

In martian mesosphere, not only water-cloud, but also CO2-cloud exists. CO2-cloud was first observed by a spectroscopy onboard Mars Express. Until today, It is found that CO2-cloud have spatial and seasonal dependence , but detail of cloud itself is not clear. We use infrared fourier spectrometer PFS which have high-spectral resolution , and it could make cloud feature clear.