Editing Europa (moon) (section)

==== Discovery of atmosphere ====
The atmosphere of Europa was first discovered in 1995 by astronomers D. T. Hall and collaborators using the [[Goddard High Resolution Spectrograph]] instrument of the [[Hubble Space Telescope]].<ref name="Hall1995">{{cite journal |last1=Hall |first1=D. T. |last2=Strobel |first2=D. F. |last3=Feldman |first3=P. D. |last4=McGrath |first4=M. A. |last5=Weaver |first5=H. A. |title=Detection of an oxygen atmosphere on Jupiter's moon Europa |date=23 February 1995 |journal=Nature |volume=373 |issue=6516 |pages=677–679 |doi=10.1038/373677a0 |pmid=7854447 |bibcode=1995Natur.373..677H }}</ref> This observation was further supported in 1997 by the ''Galileo'' orbiter during its mission within the Jovian system. The ''Galileo'' orbiter performed three radio occultation events of Europa, where the probe's radio contact with Earth was temporarily blocked by passing behind Europa. By analyzing the effects Europa's sparse atmosphere had on the radio signal just before and after the occultation, for a total of six events, a team of astronomers led by A. J. Kliore established the presence of an [[ionosphere|ionized layer]] in Europa's atmosphere.<ref name="Kliore1997">{{cite journal |last1=Kliore |first1=A. J. |last2=Hinson |first2=D. P. |last3=Flaser |first3=F. M. |last4=Nagy |first4=A. F. |last5=Cravens |first5=T. E. |title=The Ionosphere of Europa from Galileo Radio Occultations |date=18 July 1997 |journal=Science |volume=277 |issue=5324 |pages=355–358 |doi=10.1126/science.277.5324.355 |doi-access=free |pmid=9219689 |bibcode=1997Sci...277..355K }}</ref>