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Nadir and Occultation for Mars Discovery (NOMAD)

NSSDCA ID: 2016-017A-02

Mission Name: ExoMars 2016
Principal Investigator:Dr. Ann C. Vandaele


The Nadir and Occultation for MArs Discovery (NOMAD) comprises three spectrometers, two infrared and one ultraviolet. The experiment is designed to perform high-sensitivity orbital identification of atmospheric components via solar occultation and direct reflected-light nadir observations. The scientific objectives are to: 1) search for signs of past or present life on Mars; 2) investigate how the water and geochemical environment varies; 3) investigate martian atmospheric trace gases and their sources; 4) study the surface environment and identify hazards to future manned missions to mars; and 5) investigate the planet subsurface and deep interior to better understand the evolution and habitability of Mars. NOMAD's three spectrometers cover the infrared from 2.2 to 4.3 microns and the ultraviolet-visible from 0.2 to 0.65 microns. It is able to detect low concentrations of atmospheric components and map their locations.

NOMAD has three operational modes: Solar Occultation (SO); Limb, Nadir and Occultation (LNO); and Ultraviolet and Visible (UVIS). SO mode takes advantage of solar occultations as the spacecraft orbits Mars, with the instrument pointed towards the "sunset" as its light passes through the atmosphere. An occultation lasts about 5 minutes, during which 300 spectra at each of up to 6 narrow wavelength ranges are taken. These will provide a profile of the atmospheric composition with altitude. The LNO mode makes nadir observations roughly every 3 or 4 days at varying locations and local times to study atmospheric composition and surface ice and frost. The UVIS mode will target molecules such as ozone and sulphuric acid, and aerosols, taking a measurement every second at wavelengths between 200 and 600 nanometers.

Alternate Names

  • EXOMARS16/NadirandOccultationforMarsDiscovery(NOMAD)

Funding Agency

  • European Space Agency (International)


  • Planetary Science: Atmospheres

Additional Information

Questions and comments about this experiment can be directed to: Dr. David R. Williams



NameRoleOriginal AffiliationE-mail
Dr. Ann C. VandaelePrincipal InvestigatorInstitut d'Aeronomie Spatiale de Belgique
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