Laboratory Experiments

Our solar system comprises a fascinating diversity of astronomical bodies. Besides the large planets, countless smaller objects orbit the Sun. Two major groups among them are asteroids — primarily found in the asteroid belt between the orbits of Mars and Jupiter — and comets, which mainly move far outside Neptune’s orbit in the Kuiper Belt and the Oort Cloud, occasionally venturing into the inner solar system.

Because these bodies are typically small, dark, and thus difficult to observe from Earth, special space missions are required, such as the Rosetta mission to comet 67P/Churyumov–Gerasimenko or the Hayabusa2 mission to the asteroid Ryugu, to study them up close. Such missions are costly, time-consuming, and few in number. To learn more about the properties of these bodies on Earth, lab experiments can be conducted. They build on insights from past missions and help us to better understand the physical processes of small bodies in the solar system.

At the Institut für Planetologie, we build laboratories that allow us to simulate and analyze various aspects of small bodies in the solar system. For this purpose, artificial samples are first prepared to mimic, for example, the surface structure of rocky asteroids or ice-rich comets. Depending on the investigation target, these samples are transferred into a suitable experimental environment.

To this end, we design specialized measurement systems inside cryogenic ultra-high-vacuum chambers developed in-house. These enable the realization of space-like conditions with temperatures around 100 K to 400 K and pressures around 10⁻⁶ mbar.

With a variety of instruments, we study central material properties of the samples, including thermal conductivity, compressibility, and speed of sound. A future research focus will be the analysis of the activity behavior* of granular comet analog samples made of dust and ice under sun-like illumination.

In addition to quantifying physical parameters of analog materials, we also conduct experiments to develop and test instruments for space missions. The goal is to test and further develop new technologies for interacting with the surfaces of small bodies in space.

*Activity describes, for a comet, the release of gas and dust particles when exposed to sufficient solar radiation. This also forms the basis of the comet’s tail as seen from Earth.