Impact of comet Shoemaker‐Levy 9 on Jupiter

Abstract

Abstract.Three-dimensional numerical simulations of the impact of Comet Shoemaker -Levy 9 on Jupiter and the resulting vapor plume expansion were conducted using the Smoothed Particle Hydrodynamics (SPH) method. An icy body with a diameter of 2 km can penetrate to an altitude of -350 km (0 km = 1 bar) and most of the incident kinetic energy is transferred to the atmosphere between -100 km to -250 km. This energy is converted to potential energy of the resulting gas plume. The unconfined plume expands vertically and has a peak radiative power approximately equal to the total radiation from Jupiter's disc. The plume rises a few tens of atmospheric scale heights in -102 seconds. The rising plume reaches the altitude of -3000 km, but no atmospheric gas is accelerated to the escape velocity (-60 km/s).

Impact of Comet Shoemaker–Levy 9—Size, Origin, and Plumes: Comparison of Numerical Analysis with Observations

“…Several other groups also predicted various aspects of SL9 fragment impact phenomena with (1) an analytical method using the classical ablation model (Sekanina 1993, PLUME EVOLUTION Zahnle and MacLow 1994) or (2) numerical simulations (Crawford et al 1995, Boslough et al 1994 Our SPH simulations of the SL9 impact (Takata et al 1994, Ahrens et al 1994a demonstrated that the impact 1994, MacLow and Zahnle 1994).…”

Ballistic Reconstruction of HST Observations of Ejecta Motion Following Shoemaker–Levy 9 Impacts into Jupiter

“…Accordingly, from SL9's discovery until the time of the collision, a variety of prediction models detailing the events of the comet's descent and demise were produced. For example, Takata et al (1994) and Ahrens et al (1994) predicted gradual energy deposition into the jovian atmosphere as the bolide descended. In their model, the breakup of the bolide would be confined within its own bow shock, allowing the bolide to penetrate to depths of 350 km below the 1-bar level.…”

The Canyon Diablo impact event: Projectile motion through the atmosphere

“…However, this simplification leads to unrealistically thin and wide projectiles and to extremely low final velocities (essentially, deceleration is inversely proportional to the projectile's thickness). Numerical models (Ivanov et al 1992;Ahrens et al 1994;Takata et al 1994;Crawford et al 1995) carried out around the same time that the pancake model was developed (i.e., the time of the collision of comet Shoemaker-Levy 9 with Jupiter) clearly showed that although flattening ("pancaking") is a typical behavior of disrupted projectiles, it is mostly restricted to a flattening factor of 1.7-2.3. Further, widening is arrested by the growth of Kelvin-Helmholtz (K-H) and Rayleigh-Taylor (R-T) instabilities and the resulting projectile fragmentation into smaller pieces.…”