Thermal environment of the lunar poles

• Applicant: Dr.-Ing. Philipp Gläser
• Subject Area: Geodesy, Photogrammetry, Remote Sensing, Geoinformatics, Cartography
• Term: from 2016 to 2021
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 325108945

The polar regions of the Moon have complex illumination conditions and hence, also a complex surface temperature distribution. Standing at the poles, the Sun has a maximum elevation of just 1.54° over the local horizon owing to the small inclination of the lunar rotational axis with respect to the ecliptic plane. Extreme illumination conditions such as Permanently Shadowed Regions (PSRs) at crater floors, which are in darkness for several millions to billions of years, to crater rims receiving direct illumination for more than 300 days of the year can be found at the lunar poles.The overall goal of this project is to precisely map the surface temperatures near the lunar poles. The resulting temperature maps will enable the mapping of potential water ice deposits and will equip engineers with sufficient information to design future landing units at the poles withstanding local temperature gradients. Direct and indirect illumination of the Sun will be simulated using Digital Terrain Models (DTM) of the Lunar Orbiter Laser Altimeter (LOLA). Together with numerical methods for solving the heat equation the best resolved lunar temperature maps of the lunar poles will be produced. Minimum and maximum temperatures of areas as small as 20 m x 20 m (pixel size of the DTM) will shed light on the possible existence and extent of water ice deposits at crater floors but also give estimates for the expected surface temperatures for future polar landers and rovers.Recently it was discovered that several and also sometimes rather large water ice reservoirs exist at the poles which are not located within PSRs and hence very cold areas. In order to investigate the formation of these reservoirs the lunar spin-axis orientation will be changed to its former position and illumination and temperature maps will be re-calculated. We expect to find such former temperature and illumination conditions at these areas that volatiles could accumulated there in the earlier lunar history which we can still observe today.

• DFG Programme: Research Grants