Article,
High temperatures in returning ejecta from the R impact of comet SL9
Icarus, 138 (2): 164--172 (1999)
Abstract
Observations from ground-based observatories and with the Galileo
spacecraft suggest that the flares from the SL9 impacts resulted
from ejecta falling back onto Jupiter in ballistic plumes. This explanation
is supported by comparing the plume height as a function of time
in HST images with the flare light curve. We show that the rotational
temperature of CO in the shock from the R impact rose from less than
2000 K near the beginning of the main flare to about 5000 K at its
end. This behavior agrees with a simple physical model of ballistic
plumes with a mean molecular weight indicating they are 50% or more
jovian air, Alternate models involving formation of molecules at
the original impact site, or formation of dust grains to initiate
the hare, are inconsistent with these measurements. The energy is
emitted primarily as a hot continuum, supporting the possibility
that finely divided dust grains are heated in the reentry shock and
emit to create the flare. Scaling such models to the energy of the
KIT event supports proposals that ballistic plumes were responsible
for the global disaster associated with it, (C) 1999 Academic Press.
Tags
- atmosphere;
- breakup;
- collision;
- fragment-r;
- jupiter
- lightcurves
- near-infrared
- search;
- shoemaker-levy-9;
- size;
- spectroscopy;
- telescope;
- tidal
