# Hunting for Methane on Mars: one Martian year of survey with ACS on TGO

Franck Montmessin, Oleg Korablev, Anna A. Fedorova, Alexander V.

Trokhimovskiy, Franck Lefèvre, Lucio Baggio, Denis A. Belyaev, Kevin Olsen, Juan Alday, Abdanour Irbah, et al.

<figure><img src="image_1.png" /></figure>

## ► To cite this version:

Franck Montmessin, Oleg Korablev, Anna A. Fedorova, Alexander V. Trokhimovskiy, Franck Lefèvre, et al. Hunting for Methane on Mars: one Martian year of survey with ACS on TGO. Europlanet Science Congress 2020. EPSC 2020, Sep 2020, Virtual Meeting, Unknown Region. pp.EPSC2020-637, 10.5194/epsc2020-637. insu-02994808v2

HAL Id: insu-02994808

https://insu.hal.science/insu-02994808v2

Submitted on 6 Mar 2024

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# Hunting for Methane on Mars: one Martian year of survey with ACS on TGO

Franck Montmessin, Oleg Korablev, Anna A. Fedorova, Alexander V.

Trokhimovskiy, Franck Lefèvre, Lucio Baggio, Denis A. Belyaev, Kevin Olsen, Juan Alday, Abdanour Irbah, et al.

► To cite this version:

Franck Montmessin, Oleg Korablev, Anna A. Fedorova, Alexander V. Trokhimovskiy, Franck Lefèvre, et al. Hunting for Methane on Mars: one Martian year of survey with ACS on TGO. Europlanet Science Congress 2020. EPSC 2020, Sep 2020, Virtual Meeting, Unknown Region. pp.EPSC2020-637, 10.5194/epsc2020-637. insu-02994808v2

HAL Id: insu-02994808

https://insu.hal.science/insu-02994808v2

Submitted on 6 Mar 2024

HAL is a multi-disciplinary open access
archive for the deposit and dissemination of sci-
entific research documents, whether they are pub-
lished or not. The documents may come from
teaching and research institutions in France or
abroad, or from public or private research centers.

L'archive ouverte pluridisciplinaire HAL, est
destinée au dépôt et à la diffusion de documents
scientifiques de niveau recherche, publiés ou non,
émanant des établissements d'enseignement et de
recherche français ou étrangers, des laboratoires
publics ou privés.

<figure><img src="image_1.png" /></figure>

Distributed under a Creative Commons Attribution 4.0 International License
# Europlanet Science Congress 2020

Virtual meeting

21 September – 9 October 2020

Home > EPSC2020-637

## EPSC Abstracts

Vol. 14, EPSC2020-637, 2020, updated on 12 May 2022

https://doi.org/10.5194/epsc2020-637

Europlanet Science Congress 2020

© Author(s) 2022. This work is distributed under the Creative Commons Attribution 4.0 License.

<figure><img src="image_3.png" /></figure>

## Hunting for Methane on Mars: one Martian year of science on TGO

Franck Montmessin et al.

### Abstract

The Atmospheric Chemistry Suite (ACS) [1], one of the four science experiments on board ESA-Roscosmos' Trace Gas Orbiter (TGO) mission has started science operations in March 2018. ACS consists of 3 infrared unambiguous detection of trace gases of potential geophysical or biological interest. The dataset reports detection attempts conducted during the first complete Martian year (almost two Earth years) of an occultation observing mode in orbit around Mars.

The Trace Gas Orbiter (TGO) of the ESA-Roscosmos ExoMars mission has ended its trip to Mars, reaching after a year-long aerobraking phase, its scientific mission has begun on April 22nd, 2018 with the execution of the primary objective of TGO is to detect, map and locate trace gas sources, possibly revealing biological activity on Mars. The instrument of interest here is the infrared spectrometer Atmospheric covers a wavelength range from 0.7 to 17 µm at very high spectral resolution (λ / Δλ from 5,000 to 500 nm for solar occultation. Its performances complete the TGO trace gas detection arsenal together with NOMAD TGO.

A large part of the first months of the ACS observing mission has enabled the sensitive search of gas fractions of the Martian globe. The results from the first occultation up until early September 2018, incidentally covered the onset, the full development, and the demise of the Planetary Encircling Dust instruments orbiting currently around Mars. Observing conditions proved more favourable than anticipated cases to probe the Martian atmosphere close to the surface (<5 km) where the MSL Curiosity rover has seasonally varying background level of CH4 concentrations ranging between 240 and 650 pptv [2].
# Europlanet Science Congress 2020

Virtual meeting

21 September – 9 October 2020

Home > EPSC2020-637

## EPSC Abstracts

Vol. 14, EPSC2020-637, 2020, updated on 12 May 2022

https://doi.org/10.5194/epsc2020-637

Europlanet Science Congress 2020

© Author(s) 2022. This work is distributed under the Creative Commons Attribution 4.0 License.

<figure><img src="image_2.png" /></figure>

## Hunting for Methane on Mars: one Martian year of science on TGO

Franck Montmessin et al.

### Abstract

The Atmospheric Chemistry Suite (ACS) [1], one of the four science experiments on board ESA-Roscosmos' Trace Gas Orbiter (TGO) mission has started science operations in March 2018. ACS consists of 3 infrared unambiguous detection of trace gases of potential geophysical or biological interest. The dataset reports detection attempts conducted during the first complete Martian year (almost two Earth years) of an occultation observing mode in orbit around Mars.

The Trace Gas Orbiter (TGO) of the ESA-Roscosmos ExoMars mission has ended its trip to Mars, reaching a year-long aerobraking phase, its scientific mission has begun on April 22nd, 2018 with the execution of the primary objective of TGO is to detect, map and locate trace gas sources, possibly revealing biological activity on Mars. The instrument of interest here is the infrared spectrometer Atmospheric covers a wavelength range from 0.7 to 17 µm at very high spectral resolution (λ / Δλ from 5,000 to 500 nm for solar occultation. Its performances complete the TGO trace gas detection arsenal together with NOMAD TGO.

A large part of the first months of the ACS observing mission has enabled the sensitive search of gas fractions of the Martian globe. The results from the first occultation up until early September 2018, incidentally covered the onset, the full development, and the demise of the Planetary Encircling Dust instruments orbiting currently around Mars. Observing conditions proved more favourable than anticipated cases to probe the Martian atmosphere close to the surface (<5 km) where the MSL Curiosity rover has seasonally varying background level of CH4 concentrations ranging between 240 and 650 pptv [2].
<figure><img src="image_4.png" /></figure>

The first five months of ACS CH4 detection attempts were reported in [3], revealing the absence of methane on the Martian globe (Figure 1). Part of the attempts at that time was impaired by the presence of abundant dust events preventing observing the lower troposphere of Mars (<30 km) where methane, if detectable, presumably coexists.

The ACS dataset analyzed here covers a period of more than 25 months, which is five times more analyzed. This gives us a chance to perform a deeper exploration into the potential presence of methane for our understanding of active geophysical and physicochemical processes prevailing at Mars.

<figure><img src="image_5.png" /></figure>

**How to cite:** Montmessin, F., Korablev, O., Fedorova, A. A., Trokhimovskiy, A. V., Lefevre, F., Baggio, L., J., Irbah, A., Lacombe, G., Patrakeev, A., Teinturier, L., Ignatiev, N., Luginin, M., Shakun, A., Guerlet, S., Wilson, C. F.: Hunting for Methane on Mars: one Martian year of survey with ACS on TGO, Europlanet Science Journal, 21 Sep–9 Oct 2020, EPSC2020-637, https://doi.org/10.5194/epsc2020-637, 2020.
<figure><img src="image_3.png" /></figure>

The first five months of ACS CH4 detection attempts were reported in [3], revealing the absence of methane on the Martian globe (Figure 1). Part of the attempts at that time was impaired by the presence of abundant dust events preventing the observation of the lower troposphere of Mars (<30 km) where methane, if detectable, presumably does not absorb in the IR.

The ACS dataset analyzed here covers a period of more than 25 months, which is five times more analyzed. This gives us a chance to perform a deeper exploration into the potential presence of methane and to study its evolution over time.

This paper provides a framework for understanding the potential role of dust events in preventing the observation of methane in the IR.

<figure><img src="image_4.png" /></figure>

**How to cite:** Montmessin, F., Korablev, O., Fedorova, A. A., Trokhimovskiy, A. V., Lefevre, F., Baggio, L., J., Irbah, A., Lacombe, G., Patrakeev, A., Teinturier, L., Ignatiev, N., Luginin, M., Shakun, A., Guerlet, S., Wilson, C. F.: Hunting for Methane on Mars: one Martian year of survey with ACS on TGO, Europlanet Science Journal, 21 Sep-9 Oct 2020, EPSC2020-637, https://doi.org/10.5194/epsc2020-637, 2020.
© 2019 Copernicus GmbH

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© 2019 Copernicus GmbH

Header image © Europlanet Society

Data protection