TY - JOUR
T1 - No detection of methane on Mars from early ExoMars Trace Gas Orbiter observations
AU - Korablev, Oleg
AU - Avandaele, Ann Carine
AU - Montmessin, Franck
AU - Fedorova, Anna A.
AU - Trokhimovskiy, Alexander
AU - Forget, François
AU - Lefèvre, Franck
AU - Daerden, Frank
AU - Thomas, Ian R.
AU - Trompet, Loïc
AU - Erwin, Justin T.
AU - Aoki, Shohei
AU - Robert, Séverine
AU - Neary, Lori
AU - Viscardy, Sébastien
AU - Grigoriev, Alexey V.
AU - Ignatiev, Nikolay I.
AU - Shakun, Alexey
AU - Patrakeev, Andrey
AU - Belyaev, Denis A.
AU - Bertaux, Jean-Loup
AU - Olsen, Kevin S.
AU - Baggio, Lucio
AU - Alday, Juan
AU - Ivanov, Yuriy S.
AU - Ristic, Bojan
AU - Mason, Jon
AU - Willame, Yannick
AU - Depiesse, Cédric
AU - Hetey, Laszlo
AU - Berkenbosch, Sophie
AU - Clairquin, Roland
AU - Queirolo, Claudio
AU - Beeckman, Bram
AU - Neefs, Eddy
AU - Patel, Manish R.
AU - Bellucci, Giancarlo
AU - López-Moreno, Jose-Juan
AU - Wilson, Colin F.
AU - Etiope, Giuseppe
AU - Zelenyi, Lev
AU - Svedhem, Håkan
AU - Vago, Jorge L.
AU - The ACS & NOMAD Team
AU - Alonso-Rodrigo, Gustavo
AU - Altieri, Francesca
AU - Anufreychik, Konstantin
AU - Arnold, Gabriele
AU - Martin-Torres, Javier
N1 - ExoMars is the space mission of ESA and Roscosmos. The ACS experiment is led by IKI, the Space Research Institute in Moscow, assisted by LATMOS in France. The project acknowledges funding by Roscosmos and CNES. The science operations of ACS are funded by Roscosmos and ESA. IKI affiliates acknowledge funding under grant number 14.W03.31.0017 and contract number 0120.0 602993 (0028-2014-0004) of the Russian government. The NOMAD experiment is led by the Royal Belgian Institute for Space Aeronomy (BIRA-IASB), assisted by co-PI teams from Spain (IAA-CSIC), Italy (INAF-IAPS), and the UK (Open University). This project acknowledges funding by the Belgian Science Policy Office (BELSPO), with the financial and contractual coordination of the ESA Prodex Office (PEA 4000103401 and PEA 4000121493), by Spanish MICINN through its Plan Nacional and by European funds under grants ESP2015-65064-C2-1-P and ESP2017-87143-R (MINECO/FEDER), as well as by the UK Space Agency through grants ST/R005761/1, ST/P001262/1, ST/R001405/1, ST/S00145X/1, ST/R001367/1, ST/P001572/1 and ST/R001502/1, and the Italian Space Agency through grant 2018-2-HH.0. This work was supported by the Belgian Fonds de la Recherche Scientifique—FNRS under grant number 30442502 (ET_HOME). We are indebted to thelarge number of people responsible for designing, building, testing, launching, communicating to and operating the spacecraft and science instruments, whose efforts made the success of TGO possible.
PY - 2019/4/25
Y1 - 2019/4/25
N2 - The detection of methane on Mars has been interpreted as indicating that geochemical or biotic activities could persist on Mars today1. A number of different measurements of methane show evidence of transient, locally elevated methane concentrations and seasonal variations in background methane concentrations2-5. These measurements, however, are difficult to reconcile with our current understanding of the chemistry and physics of the Martian atmosphere6,7, which—given methane's lifetime of several centuries—predicts an even, well mixed distribution of methane1,6,8. Here we report highly sensitive measurements of the atmosphere of Mars in an attempt to detect methane, using the ACS and NOMAD instruments onboard the ESA-Roscosmos ExoMars Trace Gas Orbiter from April to August 2018. We did not detect any methane over a range of latitudes in both hemispheres, obtaining an upper limit for methane of about 0.05 parts per billion by volume, which is 10 to 100 times lower than previously reported positive detections2,4. We suggest that reconciliation between the present findings and the background methane concentrations found in the Gale crater4 would require an unknown process that can rapidly remove or sequester methane from the lower atmosphere before it spreads globally.
AB - The detection of methane on Mars has been interpreted as indicating that geochemical or biotic activities could persist on Mars today1. A number of different measurements of methane show evidence of transient, locally elevated methane concentrations and seasonal variations in background methane concentrations2-5. These measurements, however, are difficult to reconcile with our current understanding of the chemistry and physics of the Martian atmosphere6,7, which—given methane's lifetime of several centuries—predicts an even, well mixed distribution of methane1,6,8. Here we report highly sensitive measurements of the atmosphere of Mars in an attempt to detect methane, using the ACS and NOMAD instruments onboard the ESA-Roscosmos ExoMars Trace Gas Orbiter from April to August 2018. We did not detect any methane over a range of latitudes in both hemispheres, obtaining an upper limit for methane of about 0.05 parts per billion by volume, which is 10 to 100 times lower than previously reported positive detections2,4. We suggest that reconciliation between the present findings and the background methane concentrations found in the Gale crater4 would require an unknown process that can rapidly remove or sequester methane from the lower atmosphere before it spreads globally.
KW - Astrobiology
KW - Inner planets
KW - Atmospheric chemistry
U2 - 10.1038/s41586-019-1096-4
DO - 10.1038/s41586-019-1096-4
M3 - Article
VL - 568
SP - 517
EP - 520
JO - Nature
JF - Nature
SN - 0028-0836
ER -