These images of the Venus clouds were taken by Galileo's Solid State Imaging System February
13,1990, at a range of about1 million miles. The smallest detail visible is about 20 miles. The two
right images show Venus in violet light, the top one at a time six hours later than the bottom one.
They show the state of the clouds near the top of Venus's cloud deck. A right to left motion of the
cloud features is evident and is consistent with westward winds of about 230 mph. The two left
images show Venus in near infrared light, at the same times as the two right images. Sunlight
penetrates through the clouds more deeply at the near infrared wavelengths, allowing a view
near the bottom of the cloud deck. The westward motion of the clouds is slower (about 150 mph)
at the lower altitude. The clouds are composed of sulfuric acid droplets and occupy a range of
altitudes from 30 to 45 miles. The images have been spatially filtered to bring out small scale
details and de- emphasize global shading. The filtering has introduced artifacts (wiggly lines
running north/south) that are faintly visible in the infrared image. The Galileo Project is managed
for NASA's Office of Space Science and Applications by the Jet Propulsion Laboratory; its
mission is to study Jupiter and its satellites and magnetosphere after multiple gravity assist
flybys at Venus and Earth.
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