A stellar-occultation light curve for Triton shows asymmetry that
can be understood if Triton's middle atmosphere is distorted from
spherical symmetry. Although a globally oblate model can explain the
data, the inferred atmospheric flattening is so large that it could be
caused only by an unrealistic internal mass distribution or highly
supersonic zonal winds. Cyclostrophic winds confined to a jet near
Triton's northern or southern limbs (or both) could also be
responsible for the details of the light curve, but such winds are
required to be slightly supersonic. Hazes and clouds in the atmosphere
are unlikely to have caused the asymmetry in the light curve.
J. L. Elliot, Department of Earth, Atmospheric, and Planetary
Sciences and Department of Physics, Building 54-422, Massachusetts
Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA
02139-4307, USA; and Lowell Observatory, 1400 West Mars Hill Road,
Flagstaff, AZ 86001-4499, USA.
J. A. Stansberry and C. B. Olkin, Lowell Observatory, 1400 West Mars Hill Road, Flagstaff, AZ 86001-4499, USA.
M. A. Agner, Department of Earth, Atmospheric, and Planetary
Sciences, Building 54-314, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139-4307, USA.
M. E. Davies, RAND Corporation, 1700 Main Street, Santa Monica, CA
90407-3297, USA.
*
To whom correspondence should be addressed at the Department of
Earth, Atmospheric, and Planetary Sciences, Building 54-422, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139-4307, USA. E-mail: jle{at}mit.edu
Volume 278, Number 5337,
Issue of 17 October 1997,
pp. 436-439
