Data returned by the Galileo probe is causing scientists to have to rethink their theories regarding Jupiter's formation and the nature of planetary evolution processes, according to probe project scientist Dr. Richard Young of NASA's Ames Research Center.

Probe instruments returned data indicating that the entry region of Jupiter is drier than scientists anticipated, and the instruments did not detect the three-tiered cloud structure believed to exist. Also, the amount of helium detected was only about half of what was expected.

"The quality of the Galileo probe data exceeds all of our most optimistic predictions," said Dr. Wesley Huntress, NASA Associate Administrator for Space Science. "It will allow the scientific community to develop valuable new insights into the formation and evolution of our solar system, and the origins of life within it."

"The probe detected extremely strong winds and very intense turbulence during its descent through Jupiter's thick atmosphere. This provides evidence that the energy source driving much of Jupiter's distinctive circulation phenomena is probably heat escaping from the deep interior of the planet," said probe project scientist Dr. Richard Young, also of Ames Research Center. "The probe also discovered an intense new radiation belt approximately 31 000 miles above Jupiter's cloud tops, and a veritable absence of lightning."

These early results are exciting, but scientists caution that they are only preliminary and subject to much further analysis and refinement.

(See: http://www.jpl.nasa.gov/galileo for more information)

Preliminary Probe Results

Probe lifetime: approx. 57 minutes

Compounds Detected:



-Hydrogen Sulfide (cloud coloring agent?)

Organic compounds detected:

-Assorted hydrocarbons



Surprising Results:

1) Only 1/10 water vapor of solar baseline (should be at least 5 times that of Sun's water) - possible clinging of water vapor to the tubes of the probe's vacuum chamber or incorrect solar valve

2) Excess abundance of krypton and xenon (water ice from impacting comets early in the solar system's evolution could trap Xenon and Krypton more readily than low-mass noble gases).

-Compiled by Mark Elowitz