The Martian Oxygen Red Line Airglow: Observations With Nomad/Uvis And
Modeling
J.-C. Gérard, Lpap, Star Institute, Université De Liège, Belgium (Jc.Gerard@Uliege.Be), L. Soret, Lpap,
Star Institute, Université De Liège, Belgium, L. Gkouvelis, L. Gkouvelis, Nasa Ames Research Center, Ca,
United States, S. Aoki, University Of Tokyo, Japan, And The Nomad/Uvis Team
Detection Of Visible Emissions. The Ultraviolet And
Visible Channel (Uvis) Of The Nomad Instrument
(Vandaele Et Al., 2018; Patel Et Al., 2017) On Board
The Exomars Trace Gas Orbiter (Tgo) Has Been
Observing The Dayside Limb Of The Planet Since April
2019. For This Purpose, The Tgo Spacecraft In Moved
In Such A Way That The Nadir Channel Of The Instrument Is Oriented To The Sunlit Limb Away From The
Sun’S Direction. The Instrument Is Occasionally Operated To Collect Spectra In The Inertial Limb Mode
Where The Instrument Points At The Dayside Limb In A
Fixed Orientation (López-Valverde Et Al., 2018). By
Virtue Of The Spacecraft Motion Along Its Orbit, The
Line Of Sight Scans Through The Atmosphere Down To A
Predetermined Altitude Of The Tangent Point And Detects Ultraviolet And Visible Dayglow Emissions. In
This Inertial Tracking Mode, Only Two Altitude Scans
Through The Atmosphere (One Ingress And One Egress)