# If the rover is right, why does the orbiter see no methane? · Mars methane puzzle > Two answers have been proposed. None is ahead on the evidence yet. Two are still possible. Source: https://mysteriesdept.com/mysteries/mars-methane/questions/QST0D7EXWZE752X/if-the-rover-is-right-why-does-the-orbiter-see-no-methane Publisher: Mysteries Department Licence: CC BY 4.0 (credit Mysteries Department and link the page) Updated: 2026-10-26T11:58:00+00:00 --- **0** # If the rover is right, why does the orbiter see no methane? Asked 26 Oct 2026 by [**apollo** ](https://mysteriesdept.com/u/apollo)·Part of [Is there methane in the air at Gale crater?](https://mysteriesdept.com/mysteries/mars-methane/questions/QST0D7EXWQM6TWB/is-there-methane-in-the-air-at-gale-crater)·2 answers·0·0 following **Two answers, none ahead** None is ahead yet. See what would settle it. ## Where it stands Two answers have been proposed. None is ahead on the evidence yet. Two are still possible. ## Why it matters The orbiter's best limits are about a twentieth of the rover's background⁠[[1]](https://mysteriesdept.com/sources/SRC0D7EXPCG3CNM/a-stringent-upper-limit-of-20-pptv-for-methane-on-mars-and). Both can be right only if methane stays near the ground and disappears quickly⁠[[2]](https://mysteriesdept.com/sources/SRC0D7EXN5E4XES/the-methane-diurnal-variation-and-microseepage-flux-at-gale)⁠[[3]](https://mysteriesdept.com/sources/SRC0D7EXP4P2XCB/day-night-differences-in-mars-methane-suggest-nighttime). ## Answers 2 [**Methane seeps from the ground, is trapped near the surface at night, diluted by day, and removed by an…** ](https://mysteriesdept.com/mysteries/mars-methane/answers/ANS0D7EY0WE0WAD/methane-seeps-from-the-ground-is-trapped-near-the-surface-at) Not tested enough to call either way Evidence: 2 for, 1 against Still possible [**None of these.** ](https://mysteriesdept.com/mysteries/mars-methane/answers/ANS0D7EY1VP6BS4/none-of-these) Not tested enough to call either way Evidence: none yet Still possible ## History 1. 2009[Lefèvre & Forget: standard photochemistry gives methane a lifetime of centuries; local variations need a loss 600 times faster.](https://mysteriesdept.com/sources/SRC0D7EXKPJ0M3K/observed-variations-of-methane-on-mars-unexplained-by-known)Against: Methane seeps from the ground, is trapped near the surface at night, diluted by day, and removed by an… 1. 2019[Moores et al. puts forward: methane seeps from the ground, is trapped near the surface at night, diluted by day, and removed by an…](https://mysteriesdept.com/sources/SRC0D7EXN5E4XES/the-methane-diurnal-variation-and-microseepage-flux-at-gale) 1. 2019[Moores et al.: a steady seepage of 1.5 × 10⁻¹⁰ kg m⁻² per sol reconciles the data if only about 2.7 × 10⁴ km² emits, or if a…](https://mysteriesdept.com/sources/SRC0D7EXN5E4XES/the-methane-diurnal-variation-and-microseepage-flux-at-gale)For: Methane seeps from the ground, is trapped near the surface at night, diluted by day, and removed by an… 1. 2021[Webster et al.: the day-night difference measured in 2019 fits night-time containment.](https://mysteriesdept.com/sources/SRC0D7EXP4P2XCB/day-night-differences-in-mars-methane-suggest-nighttime)For: Methane seeps from the ground, is trapped near the surface at night, diluted by day, and removed by an… 1. 26 Oct 2026Asked on this site ## Discussion 0 [Add to the discussion](https://mysteriesdept.com/signin?next=/mysteries/mars-methane/questions/QST0D7EXWZE752X/if-the-rover-is-right-why-does-the-orbiter-see-no-methane%23discussion) Help with this question [ **Propose an answer** Something the evidence could support or rule out ] [ **Propose an answer** Something the evidence could support or rule out ](https://mysteriesdept.com/signin?next=/mysteries/mars-methane/questions/QST0D7EXWZE752X/if-the-rover-is-right-why-does-the-orbiter-see-no-methane%23add-answer) [ **Add evidence** A result for or against an answer ] [ **Add evidence** A result for or against an answer ](https://mysteriesdept.com/signin?next=/mysteries/mars-methane/questions/QST0D7EXWZE752X/if-the-rover-is-right-why-does-the-orbiter-see-no-methane%23add-evidence) [ **Ask a sub-question** A smaller question that would help settle this one ] [ **Ask a sub-question** A smaller question that would help settle this one ](https://mysteriesdept.com/signin?next=/mysteries/mars-methane/questions/QST0D7EXWZE752X/if-the-rover-is-right-why-does-the-orbiter-see-no-methane%23add-question) [ **Add a source** A paper, archive record or image ] [ **Add a source** A paper, archive record or image ](https://mysteriesdept.com/signin?next=/mysteries/mars-methane/questions/QST0D7EXWZE752X/if-the-rover-is-right-why-does-the-orbiter-see-no-methane%23add-source) Where it fits Mars methane puzzle [**Is there methane in the air at Gale crater?** ](https://mysteriesdept.com/mysteries/mars-methane/questions/QST0D7EXWQM6TWB/is-there-methane-in-the-air-at-gale-crater)Key question · 3 answers, inconclusive [Does the background follow a seasonal cycle?](https://mysteriesdept.com/mysteries/mars-methane/questions/QST0D7EXX785WEM/does-the-background-follow-a-seasonal-cycle)Open · 3 answers, inconclusive **If the rover is right, why does the orbiter see no methane?** You're here · 2 answers, inconclusive [ Ask a question under this one ]