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Titel |
The Impact of a Large Object with Jupiter in July 2009 |
VerfasserIn |
Agustín Sánchez-Lavega, A. Wesley, G. Orton, P. Chodas, R. Hueso, S. Perez-Hoyos, L. Fletcher, P. Yanamandra-Fisher, J. Legarreta, J. M. Gomez-Forrellad |
Konferenz |
EGU General Assembly 2010
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Medientyp |
Artikel
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Sprache |
Englisch
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Digitales Dokument |
PDF |
Erschienen |
In: GRA - Volume 12 (2010) |
Datensatznummer |
250045092
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Zusammenfassung |
The only major impact ever observed directly in the Solar System was that of a large
fragmented comet with Jupiter in July (1994) (Comet Shoemaker-Levy 9; SL9). We report
here the observation of a second, single, large impact on Jupiter that occurred on
19 July 2009 at a latitude of -55- with an orthogonal entry trajectory and a lower
incidence angle compared to those of SL9. The size of the initial aerosol cloud debris
was 4,800 km East-West and 2,500 km North-South. Comparison its properties
with those produced by the SL9 fragments, coupled with dynamical calculations
of possible pre-impact orbits, indicates that the impactor was most probably an
icy body with a size of 0.5-1 km. We calculate that the rate of collisions of this
magnitude may be five to ten times more frequent than previously thought. The search
for unpredicted impacts, such as the current one, could be best performed in the
near-infrared methane absorption bands at 890 nm and in the 2.12 to 2.3 μm K
methane-hydrogen absorption band, where the high-altitude aerosols detach by their
brightness relative to Jupiter’s primary clouds. We present measurements of the debris
dispersion by Jovian winds from a long-term imaging campaign with ground-based
telescopes.
Ackowledgements: Work was supported by the Spanish MICIIN AYA2009-10701 with
FEDER and Grupos Gobierno Vasco IT-464-07, by NASA funds to JPL, Caltech, by the
NASA Postdoctoral Program at JPL, and by the Glasstone Fellowship program at Oxford. |
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