... Long-Term Observations of the Evolution of the Southern Seasonal Cap of Mars: Neutron Measurements by the HEND Instrument onboard the 2001 MarsOdyssey Spacecraft, M. L. Litvak, I. G. Mitrofanov, A. S. Kozyrev, A. B. Sanin, V. I. Tret’yakov, W. V. Boynton, D. Hamara, and S. Saunders, , Solar System Research, Issue 5, Vol 41, 385, 2007 . ... Comparison between polar regions of Mars from HEND/Odyssey data, Литвак М . ... Исследования Солнечной системы, 2003, т. 37, вып. 5, стр. 378-386. (on Russian) ....
Hubble Finds Oxygen Atmosphere On Jupiter's Moon Europa . Astronomers using NASA's Hubble Space Telescope (HST) have identified the presence of an extremely tenuous atmosphere of molecular oxygen around Jupiter's second moon, Europa . ... Europa's oxygen atmosphere is so tenuous that its surface pressure is barely one hundred billionth that of the Earth," said Principal Investigator Doyle Hall, of Johns Hopkins. ... The oxygen gas slowly leaks into space and must be replenished continuously. ...