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| Content Provider | Springer Nature Link |
|---|---|
| Author | Kaufmann, Erika Kargl, Günter Kömle, rbert I. Steller, Manfred Hasiba, Johann Tatschl, Florian Ulamec, Stefan Biele, Jens Engelhardt, Marc Romstedt, Jens |
| Copyright Year | 2009 |
| Abstract | One possibility to explore the subsurface layers of icy bodies is to use a probe with a “hot tip", which is able to penetrate ice layers by melting. Such probes have been built and used in the past for the exploration of terrestrial polar ice sheets and may also become useful tools to explore other icy layers in the Solar System. Examples for such layers are the polar areas of Mars or the icy crust of Jupiter’s moon Europa. However, while on Earth a heated probe launched into an ice sheet always causes melting with subsequent refreezing, the behaviour of such a probe in a low pressure environment is quite different. We report on the results of some experiments with a simple “melting probe" prototype with two different kinds of hot tips in a vacuum environment. For one of the tips the probe moved into two types of ice samples: (i) compact water ice and (ii) porous water ice with a snow (firn) like texture. It was also found that the penetration behaviour was basically different for the two sample types even when the same kind of tip was used. While in the porous sample the ice was only subliming, the phase changes occurring during the interaction of the tip with the compact ice are much more complex. Here alternating phases of melting and sublimation occur. The absence of the liquid phase has severe consequences on the performance of a “melting probe" under vacuum conditions: In this environment we find a high thermal resistance between the probe surface and the underlying ice. Therefore, only a low percentage of the heat that is generated in the tip is used to melt or sublime the ice, the bulk of the power is transferred towards the rear end of the probe. This is particularly a problem in the initial phases of an ice penetration experiment, when the probe has not yet penetrated the ice over its whole length. In the compact ice sample, phases could be observed, where a high enough gas pressure had built up locally underneath the probe, so that melting becomes possible. Only during these melting periods the thermal contact between the probe and the ice is good and in consequence the melting probe works effectively. |
| Starting Page | 11 |
| Ending Page | 29 |
| Page Count | 19 |
| File Format | |
| ISSN | 01679295 |
| Journal | Earth, Moon, and Planets |
| Volume Number | 105 |
| Issue Number | 1 |
| e-ISSN | 15730794 |
| Language | English |
| Publisher | Springer Netherlands |
| Publisher Date | 2009-03-03 |
| Publisher Place | Dordrecht |
| Access Restriction | Subscribed |
| Subject Keyword | Planetary ices Melting probes Astrophysics Extraterrestrial Physics, Space Sciences Planetology Astronomy |
| Content Type | Text |
| Resource Type | Article |
| Subject | Astronomy and Astrophysics Space and Planetary Science |
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