The New Horizons Multispectral Visible Imaging Camera (MVIC) snapped this
incredibly detailed picture of Jupiter's high-altitude clouds starting at
06:00 Universal Time on February 28, 2007, when the spacecraft was only
2.3 million kilometers (1.4 million miles) from the solar system's largest
planet. Features as small as 50 kilometers (30 miles) are visible. The
image was taken through a narrow filter centered on a methane absorption
band near 890 nanometers, a considerably redder wavelength than what the
eye can see. Images taken through this filter preferentially pick out
clouds that are relatively high in the sky of this gas giant planet
because sunlight at the wavelengths transmitted by the filter is
completely absorbed by the methane gas that permeates Jupiter's atmosphere
before it can reach the lower clouds.
The image reveals a range of diverse features. The south pole is capped
with a haze of small particles probably created by the precipitation of
charged particles into the polar regions during auroral activity. Just
north of the cap is a well-formed anticyclonic vortex with rising white
thunderheads at its core. Slightly north of the vortex are the tendrils of
some rather disorganized storms and more pinpoint-like thunderheads. The
dark "measles" that appear a bit farther north are actually cloud-free
regions where light is completely absorbed by the methane gas and
essentially disappears from view. The wind action considerably picks up in
the equatorial regions where giant plumes are stretched into a long wave
pattern. Proceeding north of the equator, cirrus-like clouds are shredded
by winds reaching speeds of up to 400 miles per hour, and more
pinpoint-like thunderheads are visible. Although some of the famous belt
and zone structure of Jupiter's atmosphere is washed out when viewed at
this wavelength, the relatively thin North Temperate Belt shows up quite
nicely, as does a series of waves just north of the belt. The north polar
region of Jupiter in this image has a mottled appearance, and the scene is
not as dynamic as the equatorial and south polar regions.
The intricate structures revealed in this image are exciting, but they are
only part of the story. The New Horizons instruments have taken images of
Jupiter at approximately 260 different wavelengths, providing essentially
a three-dimensional view of Jupiter's atmosphere, since images at
different wavelengths probe different altitudes. New Horizons is providing
a wealth of data on this fascinating planet during this last close-up view
of Jupiter until the middle of the next decade.
