Open AccessHelium in Jupiter's atmosphere: Results from the Galileo probe Helium Interferometer Experiment
Author(s) -
Zahn U.,
Hunten D. M.,
Lehmacher G.
Publication year - 1998
Publication title -
journal of geophysical research: planets
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.67
H-Index - 298
eISSN - 2156-2202
pISSN - 0148-0227
DOI - 10.1029/98je00695
Subject(s) - jovian , atmosphere of jupiter , jupiter (rocket family) , helium , atmosphere (unit) , physics , astronomy , interferometry , atmospheric escape , planet , astrophysics , astrobiology , atomic physics , meteorology , saturn , space shuttle
On December 7, 1995, the NASA Galileo probe provided the first in situ measurements of the helium abundance in the atmosphere of Jupiter. Our Jamin interferometer measured precisely the refractive index of the Jovian atmosphere in the pressure region from 2 to 12 bars. From these measurements, we derive the atmospheric helium mole fraction to be 0.1359±0.0027. The corresponding helium mass fraction matches closely, but accidentally, the current helium abundance of the atmosphere of the Sun. However, both the Jovian and the solar value fall somewhat below the protosolar value. This suggests that in both Jupiter and the Sun processes are active which separate helium from hydrogen.