  Jupiter was imaged during the Science Demonstration of the MCAO Demonstrator
(MAD) at the European Southern Observatory's UT3 Very Large Telescope unit. Io
and Europa were used as natural guide stars on either side of Jupiter,
separated from each other by about 1.6 arcmin from 23:41 to 01:32 UT (2008 Aug
16/17). The corrected angular resolution was 0.090 arcsec across the entire
field of view, as measured on background stars.
  The observations at 2.02, 2.14, and 2.16 micrometers were sensitive to
portions of the Jovian spectrum with strong methane absorption. The data probe
the upper troposphere, which is populated with a fine (~0.5 micrometer) haze.
Two haze sources have been proposed: lofting of fine cloud particles into the
stable upper troposphere, and condensation of hydrazine produced via ammonia
photochemistry. The upper tropospheric haze is enhanced over Jupiter's
equatorial region.
  Dramatic changes in the underlying cloud cover--part of the 2006/2007 "global
upheaval"--may be associated with changes in the equatorial haze distribution
now evident in the 2008 MAD images. Haze reflectivity peaked at 5 degrees N in
HST/NICMOS data from 2005, but it now peaks at the equator. The observations
suggest that haze variation is controlled by particle size, cloud source
variation, diffusion, and horizontal transport.
