# ExoMars Trace Gas Orbiter solar-occultation spectra (ACS and NOMAD)

> Spectra of sunlight through the atmosphere at sunrise and sunset, sensitive to tens of parts per trillion above a few kilometres. They find no methane…

Source: https://mysteriesdept.com/mysteries/mars-methane/artifacts/ART0D7EYA5A2BZF/exomars-trace-gas-orbiter-solar-occultation-spectra-acs-and  
Publisher: Mysteries Department  
Licence: CC BY 4.0 (credit Mysteries Department and link the page)  

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**ART** 0D7EYA5A2BZF·Artifact · recording

# ExoMars Trace Gas Orbiter solar-occultation spectra (ACS and NOMAD)

PhotographCC BY-SA 3.0 IGOFrom April 2018; no detection reported April 2019

[Cite][Download](https://mysteriesdept.com/files/d/3328f2c867ab0628e3bd69713fe8c88c9ac50b7d0189421ed9f86527c37dd773)

[![ExoMars Trace Gas Orbiter solar-occultation spectra (ACS and NOMAD): document](https://mysteriesdept.com/files/v/3328f2c867ab0628e3bd69713fe8c88c9ac50b7d0189421ed9f86527c37dd773/w800)](https://mysteriesdept.com/files/3328f2c867ab0628e3bd69713fe8c88c9ac50b7d0189421ed9f86527c37dd773.jpg)

ExoMars Trace Gas Orbiter solar-occultation spectra (ACS and NOMAD): document

Spectra of sunlight through the atmosphere at sunrise and sunset, sensitive to tens of parts per trillion above a few kilometres. They find no methane, to a limit a twentieth of the rover's background.

ESA, 2018. CC BY-SA 3.0 IGO

## Copies 3

**Dataset** NOMAD team · archives.esac.esa.int · ESA PSA terms (acknowledge the PI and the PSA)Primary source: [ESA Planetary Science Archive: ExoMars 2016 Trace Gas Orbiter (ACS and NOMAD)](https://mysteriesdept.com/sources/SRC0D7EXQKJ5NVV/esa-planetary-science-archive-exomars-2016-trace-gas-orbiter)1 step from the original

[Where it's published](https://archives.esac.esa.int/psa/ftp/ExoMars2016/em16_tgo_nmd/)

**Dataset** ACS team · archives.esac.esa.int · ESA PSA terms (acknowledge the PI and the PSA)Primary source: [ESA Planetary Science Archive: ExoMars 2016 Trace Gas Orbiter (ACS and NOMAD)](https://mysteriesdept.com/sources/SRC0D7EXQKJ5NVV/esa-planetary-science-archive-exomars-2016-trace-gas-orbiter)1 step from the original

[Where it's published](https://archives.esac.esa.int/psa/ftp/ExoMars2016/em16_tgo_acs/)

**Document** ESA · commons.wikimedia.org · 2019-04-10 · CC BY-SA 3.0 IGO3 steps from the original

[Where it's published](https://commons.wikimedia.org/wiki/File:Key_methane_measurements_at_Mars.jpg)[Download](https://mysteriesdept.com/files/d/3328f2c867ab0628e3bd69713fe8c88c9ac50b7d0189421ed9f86527c37dd773)

## Sources 2

- [A stringent upper limit of 20 pptv for methane on Mars and constraints on its dispersion outside Gale crater](https://mysteriesdept.com/sources/SRC0D7EXPCG3CNM/a-stringent-upper-limit-of-20-pptv-for-methane-on-mars-and)_SRC_
- [No detection of methane on Mars from early ExoMars Trace Gas Orbiter observations](https://mysteriesdept.com/sources/SRC0D7EXMNT4W0Z/no-detection-of-methane-on-mars-from-early-exomars-trace-gas)_SRC_

## Cite it

```
Mysteries Department. (2026). ExoMars Trace Gas Orbiter solar-occultation spectra (ACS and NOMAD) [Artifact ART0D7EYA5A2BZF]. https://mysteriesdept.com/r/ART0D7EYA5A2BZF
```

Key

**ART** 0D7EYA5A2BZF

Kind

Recording

Held by

ESA Planetary Science Archive (ACS team, IKI Moscow; NOMAD team, BIRA-IASB Brussels)

Dated

from April 2018; no detection reported April 2019; 20 pptv upper limit from 1.44 Mars years, 2021

Licence

CC BY-SA 3.0 IGO

Part of

[Mars methane puzzle](https://mysteriesdept.com/mysteries/mars-methane)

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