Experimentelle Planetenphysik

The department has a long standing heritage in infrared and terahertz remote sensing and laboratory spectroscopy. Based on this heritage it participates in a number of missions, namely MESSENGER, SOFIA (GREAT, upGREAT), BIOMEX, BepiColombo (MERTISI), ExoMars (RLS, WISDOM), MarsExpress (PFS) and VenusExpress (VIRTIS). The analysis of data obtained with these instruments is an important research activity. Spectroscopic techniques which are established in the department are Fourier transform infrared (FTIR) spectroscopy, Raman spectroscopy, Laser Induced Breakdown Spectroscopy (LIBS) and terahertz (THz) spectroscopy. These techniques provide key information for example on surface composition and mineralogy. The significance of robotic exploration of planets, moons and small bodies is rapidly growing. Besides robotic exploration the analysis of extraterrestrial material, possibly returned by dedicated missions is another important topic. The department addresses both by developing miniaturized Raman and LIBS spectrometers for in-situ exploration and by analyzing extraterrestrial material using Raman micro-spectroscopy. In some more detail the scientific objectives are:

Spectroscopy of planetary analog materials in support of current and future space missions: Terrestrial material which closely resembles material from Mars and Mercury is spectroscopically investigated using FTIR, Raman and LIBS. The data serve as a guide for the development of novel spectrometers and provide a reference library for the interpretation of mission data.	Thermal decomposition of sulfides at Mercury peak surface temperatures of 700K observed at PEL as analog for hollow formation on Mercury.
Microscopic image of a sample from the astroid Itokawa returned by the Hayabusa mission. The colors represent the mineral phases derived from the Raman spectra.	Sample analysis: In addition to analog materials real extraterrestrial samples are investigated using Raman micro-spectroscopy and infrared spectroscopy. A recent highlight is the investigation of the specific chemical composition of the minerals that make up the dust particles which were returned from the asteroid Itokawa by the Japanese Hayabusa mission. The long term goal is to establish a sample analysis laboratory which allows performing first-hand sample analysis with respect to elemental, isotopical and mineralogical composition of samples returned from missions to asteroids, moons or Mars.
Astrobiological research: The survival potential and photosynthetic activity of various microorganisms (extremophiles) is studied in a dedicated chamber, which enables the simulation of the Martian atmosphere with respect to chemical composition, humidity and temperature including diurnal variation. The goal is to understand which species can survive under e.g. Martian conditions and which biological mechanisms enable this.	Mars Simulation Facility Laboratory (MSF Lab)
THz silicon laser and superconducting hot-electron bolometric mixer.	Terahertz research: THz components and THz systems are developed for applications in astronomy, planetary research, and security. Examples are a heterodyne spectrometer for SOFIA, and a stand-off imaging system capable of detecting hidden objects. Another focus is THz-components which are required for spectrometers and imaging systems for various applications. Examples are quantum-cascade lasers, silicon lasers and superconducting hot electron bolometers.
Enabling technologies: Technologies for future space instruments are developed. Examples are miniaturized infrared remote sensing instruments or novel detectors and lasers for compact LIBS and THz spectrometers. An important aspect is the spin-off use of such technologies for example in security research. The combination of instrument concept development, laboratory measurements and development of new data analysis techniques in the department provides strong synergies that will support a wide range of future missions – both for in-situ and remote sensing instrumentation.	Portable LIBS system with laser and sensor head.