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| Titel |
Magnetism of Minor Bodies in the Solar System: From 433 Eros, passing Braille, Steins, and Lutetia towards Churyumov-Gerasimenko and 1999 JU3. |
| VerfasserIn |
David Hercik, Hans-Ulrich Auster, Philip Heinisch, Ingo Richter, Karl-Heinz Glassmeier |
| Konferenz |
EGU General Assembly 2015
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 17 (2015) |
| Datensatznummer |
250111179
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| Publikation (Nr.) |
 EGU/EGU2015-11266.pdf |
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| Zusammenfassung |
| Minor bodies in the solar system, such as asteroids and comets, are important sources
of information for our knowledge of the solar system formation. Besides other
aspects, estimation of a magnetization state of such bodies might prove important in
understanding the early aggregation phases of the protoplanetary disk, showing the
level of importance of the magnetic forces in the processes involved. Meteorites’
magnetization measurements suggest that primitive bodies consist of magnetized
material. However, space observations from various flybys give to date diverse
results for a global magnetization estimation. The flybys at Braille and Gaspra
indicate possible higher magnetization (~ 10-3 Am2/kg), while flybys at Steins
and Lutetia show no significant values in the global field change illustrating low
global magnetization. Furthermore, the interpretation of remote (during flybys)
measurements is very difficult. For correct estimates on the local magnetization one needs
(in the best case) multi-point surface measurements. Single point observation has
been done by NEAR-Shoemaker on 433 Eros asteroid, revealing no signature in
magnetic field that could have origin in asteroid magnetization. Similar results, no
magnetization observed, have been provided by evaluation of recent data from
ROMAP (Philae lander) and RPC-MAG (Rosetta orbiter) instruments from comet
67P/Churyumov-Gerasimenko. The ROMAP instrument provided measurements from
multiple points of the cometary surface as well as data along ballistic path between
multiple touchdowns, which support the conclusion of no global magnetization.
However, even in case of the in-situ on surface observations the magnetization
estimate has a limiting spatial resolution that is dependent on the distance from the
surface (~ 50 cm in case of ROMAP). To get information about possible smaller
magnetized grains distribution and magnetization strength, the sensor shall be placed as
close as possible to the surface. For such observations the next ideal candidate
mission is Hayabusa-II with its Mascot lander equipped with fluxgate magnetometer.
The small-sized lander shall deliver the magnetometer within centimeters from the
surface, providing measurements on multiple points thanks to a hopping ability. The
mission has been recently launched (December 2014) and is aiming to a C-type
asteroid 1999 JU3 to reach it in 2018. The results will hopefully add some piece of
information to the still unclear question of minor solar system bodies magnetization. |
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