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Comet Shoemaker‐Levy 9: Fragment and progenitor impact energy
Author(s) -
Takata Toshiko,
Ahrens Thomas J.,
Harris Alan W.
Publication year - 1995
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/95gl02237
Subject(s) - comet , jupiter (rocket family) , physics , astrophysics , plume , astronomy , hubble space telescope , astrobiology , spacecraft , stars , meteorology
Initial observational data from the impact of fragments of Comet Shoemaker‐Levy 9 (SL9) are compared with smoothed particle hydrodynamic (SPH) calculations to determine their pre‐impact diameters and the equivalent diameter of the SL9 progenitor. Diameters (solid ice) of 2.0±0.1, 2.0±0.05, 2.1±0.04 and 1.9±0.05 km for fragments A, E, G1, and W are obtained from impact‐induced plume heights from the Hubble Space Telescope (HST) data. Applying these values to scale apparent diameters for the balance of 18 SL fragments in Weaver et al.'s [1995] catalog of 22 objects yields a SL9 progenitor diameter of 5.0±1.8 km. This corresponds to total impact energy of 1.2 (+1.8−0.8) × 10 30 erg. Such an energetic event occurs on Jupiter and Earth at least every 4,900 +4,700, −2,700, and ∼0.5 × 10 8 years, respectively.