All you can measure at the Planetary Emissivity Laboratory (PEL) at DLR, in Berlin

The Institute for Planetary Research has an expertise in spectroscopy of minerals, rocks, meteorites, and organic matter, build up in more than two decades. The available equipment allows spectroscopy from the visible to TIR range using bi-conical reflection, transmission and emission spectroscopy. The institute has an outstanding heritage in designing and building infrared remote-sensing instruments for planetary missions. The PEL has been operating in various configurations for the last 10 years. The laboratory experimental facilities consist of the main emissivity spectrometer laboratory, a supporting spectrometer laboratory for reflectance and transmission measurements, sample preparation facilities and an extensive collection of rocks and minerals

Laboratory studies of thermal space weathering on airless bodies

Deriving the surface composition of Mercury from remote sensing hyper spectral data is a challenging task. Mercury’s surface has a low iron abundance, which complicates the application of “traditional” space weathering approach. In addition the high temperatures on Mercury lead to previously unseen changes in the spectral characteristics, which we call “thermal space weathering”. The Planetary Emissivity Laboratory (PEL) at DLR in Berlin was setup specifically to study the effects of high temperatures on the spectral characteristics of planetary analog materials. It allows characterizing “thermal space weathering” and adds temperature as another important factor for the creation of spectral libraries. Thermal space weathering can produce reversible as well as irreversible changes in the spectral characteristics of materials. In comparison to “traditional space weathering” it acts on much shorter timescales. We are going to present a number of examples for thermal space weathering effects in the visible as well as infrared spectral range

On the Effect of Emerging Angle on Emissivity Spectra: Application to Small Bodies

We studied the influence of emerging angle on emissivity spectra measured in air and in vacuum, with particular attention to asteroids-like conditions

Transmittance, Reflectance and Emission Spectroscopy of Meteorites from the IV to the IR Spectral Range

In the last decade the Planetary Emissivity Laboratory (PEL) of DLR in Berlin has provided spec-tral measurements of planetary analogues from the visible to the far-infrared range for comparison with remote sens-ing spacecraft/telescopic measurements of planetary surfaces [1-5]. Bi-directional reflection, transmission and emis-sion spectroscopy are the techniques we used to acquire spectral data of target materials. In fall 2015 we started upgrading our laboratory set-up, adding a new spectrometer, three external sources, and new detectors and beamsplitters to further extend the spectral range of measurements that can be performed in the laboratory. Reflecting the wider scope of measurement capabilities the facility was renamed to Planetary Spectros-copy Laboratory (PSL). Two FTIR instruments are operating at PSL, in an air-conditioned room. The spectrometers are two Bruker Ver-tex 80V that can be evacuated to ~.1 mbar. One spectrometer is equipped with aluminum mirrors optimized for the UV, visible and near-IR, the second features gold-coated mirrors for the near to far IR spectral range. Apart from the mirrors the two instruments are identical, and can therefore share the collection of detectors and beamsplitters we have in our equipment to cover a very wide spectral range. The instruments and the accessory units used are fully automatized and the data calibration and reduction are made with software developed at DLR[4]. By using several pairings of detector+beamsplitter we can perform spectral measurements in the whole spectral range from 0.2 to 200 μm

Studying Io's Volcanic History Using Thermal Infrared Measurements

A new thermal infrared instrumentation to observe Io combined with the unique capabilities of PEL will provide new insights into the evolution of Io

Reflectance and Emissivity spectra of graphite as potential darkening agent for Mercury from the UV to the TIR and its Comparison to Remote Sensing Measurements from MESSENGER and Mertis on BepiColombo

For long time Mercury was considered a planet very similar to the Moon. Both are small rocky bodies in the inner solar system with thin exospheres and no large scale traces of recent geological activity. However Mercury’s surface reflects much less sunlight than the Moon. Trying to explain the reasons for this difference, significant abundances of iron and titanium (and their oxides) were proposed for the Hermean surface. But the NASA MESSENGER instruments found only small abundances of iron, confirming earlier ground-based spectroscopy observations, and virtually no titanium. Therefore neither of the elements can account for this diversity. New analysis of MESSENGER data acquired for the darkest regions of Mercury’s surface suggest that the unknown darkening material could be carbon, in particular as the mineral graphite [1] whose abundance in the darker regions is predicted to be 1 to 3 wt% higher than the surroundings