Hord C W, Barth C A, Esposito L W, McClintock W E, Pryor W R, Simmons K E, Stewart A I, Thomas G E, Ajello J M, Lane A L, West R W, Sandel B R, Broadfoot A L, Hunten D M, Shemansky D E
Science. 1991 Sep 27;253(5027):1548-50. doi: 10.1126/science.253.5027.1548.
The Galileo Extreme Ultraviolet Spectrometer obtained a spectrum of Venus atmospheric emissions in the 55.0- to 125.0-nanometer (nm) wavelength region. Emissions of helium (58.4 nm), ionized atomic oxygen (83.4 nm), and atomic hydrogen (121.6 nm), as well as a blended spectral feature of atomic hydrogen (Lyman-beta) and atomic oxygen (102.5 nm), were observed at 3.5-nm resolution. During the Galileo spacecraft cruise from Venus to Earth, Lyman-alpha emission from solar system atomic hydrogen (121.6 nm) was measured. The dominant source of the Lyman-alpha emission is atomic hydrogen from the interstellar medium. A model of Galileo observations at solar maximum indicates a decrease in the solar Lyman-alpha flux near the solar poles. A strong day-to-day variation also occurs with the 27-day periodicity of the rotation of the sun.
伽利略极紫外光谱仪获取了金星大气层在55.0至125.0纳米波长区域的发射光谱。观测到了氦（58.4纳米）、电离原子氧（83.4纳米）和原子氢（121.6纳米）的发射，以及原子氢（莱曼β）和原子氧（102.5纳米）的混合光谱特征，分辨率为3.5纳米。在伽利略号航天器从金星飞往地球的巡航过程中，测量了来自太阳系原子氢的莱曼α发射（121.6纳米）。莱曼α发射的主要来源是星际介质中的原子氢。太阳活动极大期时伽利略观测的一个模型表明，太阳两极附近的太阳莱曼α通量有所下降。太阳自转的27天周期也会导致日变化强烈。
