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N.P.J. van den Heuvel
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The surfaces of icy moons such as Europa and Enceladus are covered in H2O ice grains. How such grains form under icy moon conditions is known only indirectly. This thesis addresses that question experimentally. A protocol was developed to freeze a consolidated piece of water ice from the top down inside the PISCES vacuum chamber at TU Delft. This ice it then held at pressures down to 10-3 mbar to drive its surface out of equilibrium with its surroundings. A monochrome camera resolved the surface morphology and a microsecond-resolution event camera resolved the material leaving it.
The surface did not sublimate uniformly. It eroded into upright millimetre-scale spikes that thinned at their base, detached, and were carried upward. Over 10,000 grain trajectories were reconstructed. A temperature-dependent Hertz-Knudsen model accounts for most of the measured mass loss, and a free-molecular force balance shows the ejected grains cannot be compact ice. Extrapolated to icy moon conditions, the Enceladus South Polar Terrain is the one environment considered that is warm enough to eject grains, indicating a passive thermodynamic pathway for generating porous regolith. ...
The surface did not sublimate uniformly. It eroded into upright millimetre-scale spikes that thinned at their base, detached, and were carried upward. Over 10,000 grain trajectories were reconstructed. A temperature-dependent Hertz-Knudsen model accounts for most of the measured mass loss, and a free-molecular force balance shows the ejected grains cannot be compact ice. Extrapolated to icy moon conditions, the Enceladus South Polar Terrain is the one environment considered that is warm enough to eject grains, indicating a passive thermodynamic pathway for generating porous regolith. ...
The surfaces of icy moons such as Europa and Enceladus are covered in H2O ice grains. How such grains form under icy moon conditions is known only indirectly. This thesis addresses that question experimentally. A protocol was developed to freeze a consolidated piece of water ice from the top down inside the PISCES vacuum chamber at TU Delft. This ice it then held at pressures down to 10-3 mbar to drive its surface out of equilibrium with its surroundings. A monochrome camera resolved the surface morphology and a microsecond-resolution event camera resolved the material leaving it.
The surface did not sublimate uniformly. It eroded into upright millimetre-scale spikes that thinned at their base, detached, and were carried upward. Over 10,000 grain trajectories were reconstructed. A temperature-dependent Hertz-Knudsen model accounts for most of the measured mass loss, and a free-molecular force balance shows the ejected grains cannot be compact ice. Extrapolated to icy moon conditions, the Enceladus South Polar Terrain is the one environment considered that is warm enough to eject grains, indicating a passive thermodynamic pathway for generating porous regolith.
The surface did not sublimate uniformly. It eroded into upright millimetre-scale spikes that thinned at their base, detached, and were carried upward. Over 10,000 grain trajectories were reconstructed. A temperature-dependent Hertz-Knudsen model accounts for most of the measured mass loss, and a free-molecular force balance shows the ejected grains cannot be compact ice. Extrapolated to icy moon conditions, the Enceladus South Polar Terrain is the one environment considered that is warm enough to eject grains, indicating a passive thermodynamic pathway for generating porous regolith.
L.O.V.E. mission
Life On Venus Exploration
Bachelor thesis
(2022)
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J.M. Rothenbuchner, A.J. Phillips, T.J.J. Goetzee, S. Dhiyaneeswaran, J.J.P. Bos, F. ten Voorde, N.P.J. van den Heuvel, D.J. Nieuwenhuizen, A.A. Land, C. Castro Garcia, J.A. Melkert
When searching for life we tend to imagine faraway exoplanets, and rarely do we think of our
own solar system. Although a lot of focus is put on Mars, Venus, our closest neighbor, could
currently host life. Temperatures of 475 ℃ and pressures 95 times what we experience on
Earth don’t offer the best conditions for life on the surface. However at high altitudes the
temperature and pressure drop until, in the area between 50 and 70 km, they approach those
of Earth. Here, amongst a thick deck of sulfuric acid clouds, it is speculated that life could
exist, perhaps in the form of bacteria living in suspended water bubbles.
The purpose of our mission is to design a remote sensing platform to perform in-situ
measurements on the atmosphere and soil composition of Venus, in an effort to learn more
about the planet while looking for specific biomarkers that could be attributed to life. ...
own solar system. Although a lot of focus is put on Mars, Venus, our closest neighbor, could
currently host life. Temperatures of 475 ℃ and pressures 95 times what we experience on
Earth don’t offer the best conditions for life on the surface. However at high altitudes the
temperature and pressure drop until, in the area between 50 and 70 km, they approach those
of Earth. Here, amongst a thick deck of sulfuric acid clouds, it is speculated that life could
exist, perhaps in the form of bacteria living in suspended water bubbles.
The purpose of our mission is to design a remote sensing platform to perform in-situ
measurements on the atmosphere and soil composition of Venus, in an effort to learn more
about the planet while looking for specific biomarkers that could be attributed to life. ...
When searching for life we tend to imagine faraway exoplanets, and rarely do we think of our
own solar system. Although a lot of focus is put on Mars, Venus, our closest neighbor, could
currently host life. Temperatures of 475 ℃ and pressures 95 times what we experience on
Earth don’t offer the best conditions for life on the surface. However at high altitudes the
temperature and pressure drop until, in the area between 50 and 70 km, they approach those
of Earth. Here, amongst a thick deck of sulfuric acid clouds, it is speculated that life could
exist, perhaps in the form of bacteria living in suspended water bubbles.
The purpose of our mission is to design a remote sensing platform to perform in-situ
measurements on the atmosphere and soil composition of Venus, in an effort to learn more
about the planet while looking for specific biomarkers that could be attributed to life.
own solar system. Although a lot of focus is put on Mars, Venus, our closest neighbor, could
currently host life. Temperatures of 475 ℃ and pressures 95 times what we experience on
Earth don’t offer the best conditions for life on the surface. However at high altitudes the
temperature and pressure drop until, in the area between 50 and 70 km, they approach those
of Earth. Here, amongst a thick deck of sulfuric acid clouds, it is speculated that life could
exist, perhaps in the form of bacteria living in suspended water bubbles.
The purpose of our mission is to design a remote sensing platform to perform in-situ
measurements on the atmosphere and soil composition of Venus, in an effort to learn more
about the planet while looking for specific biomarkers that could be attributed to life.