Day-night differences in Mars methane suggest nighttime containment at Gale crater

@article{Webster2021DaynightDI,
  title={Day-night differences in Mars methane suggest nighttime containment at Gale crater},
  author={Christopher R. Webster and P. M. Mahaffy and Jorge Pla‐Garc{\'i}a and Scot C. R. Rafkin and John E. Moores and Sushil K. Atreya and Gregory J. Flesch and Charles Malespin and Samuel Teinturier and Hemani Kalucha and Christina L. Smith and Daniel Vi{\'u}dez‐Moreiras and Ashwin R. Vasavada},
  journal={Astronomy \& Astrophysics},
  year={2021}
}
We report new measurements of atmospheric methane by the Curiosity rover’s Tunable Laser Spectrometer that is part of the Sample Analysis at Mars suite (TLS-SAM), finding nondetections during two daytime measurements of average value 0.05 ± 0.22 ppbv (95% confidence interval CI). These are in marked contrast with nighttime background levels of 0.52 ± 0.10 (95% CI) from four measurements taken during the same season of northern summer. This large day-night difference suggests that methane… 

Figures and Tables from this paper

Constraints on Emission Source Locations of Methane Detected by Mars Science Laboratory
The Sample Analysis at Mars (SAM) instrument on the Mars Science Laboratory (MSL) Curiosity rover has detected both methane spikes and variable background methane abundance in recent years in Gale
Mars Methane Sources in Northwestern Gale Crater Inferred From Back Trajectory Modeling
During its first seven years of operation, the Sample Analysis at Mars Tunable Laser Spectrometer (TLS) on board the Curiosity rover has detected seven methane spikes above a low background abundance
Mission Overview and Scientific Contributions from the Mars Science Laboratory Curiosity Rover After Eight Years of Surface Operations
  • A. Vasavada
  • Environmental Science
    Space science reviews
  • 2022
NASA’s Mars Science Laboratory mission, with its Curiosity rover, has been exploring Gale crater (5.4° S, 137.8° E) since 2012 with the goal of assessing the potential of Mars to support life. The
Atmospheric processes affecting methane on Mars
Planetary Mass Spectrometry for Agnostic Life Detection in the Solar System
For the past fifty years of space exploration, mass spectrometry has provided unique chemical and physical insights on the characteristics of other planetary bodies in the Solar System. A variety of
Depleted carbon isotope compositions observed at Gale crater, Mars
TLDR
Carbon isotopic values of methane released during pyrolysis of 24 powder samples at Gale crater, Mars, show a high degree of variation, but no single explanation can be accepted without further research.
From Atmospheric Evolution to the Search of Species of Astrobiological Interest in the Solar System—Case Studies Using the Planetary Spectrum Generator
The study of minor chemical species in terrestrial planets’ atmospheres can teach us about the chemistry, dynamics and evolution of the atmospheres through time. Phosphine or methane on terrestrial

References

SHOWING 1-10 OF 35 REFERENCES
No detection of methane on Mars from early ExoMars Trace Gas Orbiter observations
TLDR
Highly sensitive measurements of the atmosphere of Mars with the ExoMars Trace Gas Orbiter do not detect any methane over a range of latitudes in both hemispheres, in contrast to previous local or remote detections.
Comparing MSL Curiosity Rover TLS‐SAM Methane Measurements With Mars Regional Atmospheric Modeling System Atmospheric Transport Experiments
The detection of methane at Gale crater by the Tunable Laser Spectrometer–Sample Analysis at Mars instrument aboard the Curiosity rover has garnered significant attention because of the implications
First detection of ozone in the mid-infrared at Mars: implications for methane detection
Aims. The ExoMars Trace Gas Orbiter was sent to Mars in March 2016 to search for trace gases diagnostic of active geological or biogenic processes. Methods. We report the first observation of the
Background levels of methane in Mars’ atmosphere show strong seasonal variations
TLDR
In situ measurements at Gale crater made over a 5-year period by the Tunable Laser Spectrometer on the Curiosity rover show large seasonal variation in the background and occurrences of higher temporary spikes that are consistent with small localized sources of methane released from martian surface or subsurface reservoirs.
The Methane Diurnal Variation and Microseepage Flux at Gale Crater, Mars as Constrained by the ExoMars Trace Gas Orbiter and Curiosity Observations
The upper bound of 50 parts per trillion by volume for Mars methane above 5 km established by the ExoMars Trace Gas Orbiter, substantially lower than the 410 parts per trillion by volume average
Methane seasonal cycle at Gale Crater on Mars consistent with regolith adsorption and diffusion
A strong, repeatable seasonal cycle in the background methane mixing ratio has been observed at the Gale Crater landing site of the Mars Science Laboratory rover with the Tunable Laser Spectrometer
Mars methane detection and variability at Gale crater
TLDR
Curiosity confirms the presence and variability of atmospheric methane, implying episodic production from an unknown source, and reports of plumes or patches of methane in the martian atmosphere that vary over monthly time scales have defied explanation.
Curiosity Mars methane measurements are not confused by ozone
In the detection of methane in the atmosphere of Mars by the Tunable Laser Spectrometer on the Sample Analysis at Mars (TLS-SAM) on the Curiosity rover, the possibility of confusing ozone lines with
Independent confirmation of a methane spike on Mars and a source region east of Gale Crater
Reports of methane detection in the Martian atmosphere have been intensely debated. The presence of methane could enhance habitability and may even be a signature of life. However, no detection has
...
...