# Methane is present near the surface at Gale at a background of a few tenths of a ppbv, with occasional…

> Disputed: Methane is present near the surface at Gale at a background of a few tenths of a ppbv, with occasional releases of several to tens of ppbv.

Source: https://mysteriesdept.com/mysteries/mars-methane/answers/ANS0D7EXXYP7TFK/methane-is-present-near-the-surface-at-gale-at-a-background  
Publisher: Mysteries Department  
Licence: CC BY 4.0 (credit Mysteries Department and link the page)  

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

Answer · Mars methane puzzle

# Methane is present near the surface at Gale at a background of a few tenths of a ppbv, with occasional…

Methane is present near the surface at Gale at a background of a few tenths of a ppbv, with occasional releases of several to tens of ppbv.

**Disputed** Answers **1** questionPublished0

## Where it stands

**Disputed** Four pieces of evidence for, two against. It needs two reviews to be accepted.

## What it predicts

- Repeated measurements reproduce the background and its day-night difference.
- Methane in the sample cell does not track methane in the foreoptics chamber.
- A second, independent instrument at the surface measures similar values.

## What would rule it out

- The two-step leak test, or any controlled experiment, showing that methane in the sample cell follows the foreoptics chamber.

## Evidence 4 for · 2 against

[Background 0.41 ± 0.16 ppbv over five years with spikes of about 7 ppbv.](https://mysteriesdept.com/mysteries/mars-methane/evidence/EVD0D7EXY6G39D8/background-0-41-0-16-ppbv-over-five-years-with-spikes-of)

Supported

FOR

[Mars Express PFS recorded methane over the Gale region a day after a rover spike in 2013.](https://mysteriesdept.com/mysteries/mars-methane/evidence/EVD0D7EXYXY5XM0/mars-express-pfs-recorded-methane-over-the-gale-region-a-day)

Suggestive

FOR

[Night-time values of 0.52 ± 0.10 ppbv against daytime 0.05 ± 0.22 ppbv in the same season.](https://mysteriesdept.com/mysteries/mars-methane/evidence/EVD0D7EXYEA5KCC/night-time-values-of-0-52-0-10-ppbv-against-daytime-0-05-0)

Supported

FOR

[Ozone cannot be confused with methane at TLS resolution.](https://mysteriesdept.com/mysteries/mars-methane/evidence/EVD0D7EXYP45B8Y/ozone-cannot-be-confused-with-methane-at-tls-resolution)

Supported

FOR

[The foreoptics chamber held methane three to four orders of magnitude above the sample cell; leaks under 0.1…](https://mysteriesdept.com/mysteries/mars-methane/evidence/EVD0D7EXZ5R0DK1/the-foreoptics-chamber-held-methane-three-to-four-orders-of)

Suggestive

AGAINST

[Triplet-line discrepancies in five experiments have a probability of about 10⁻³ under the reported errors,…](https://mysteriesdept.com/mysteries/mars-methane/evidence/EVD0D7EXZDJ40GJ/triplet-line-discrepancies-in-five-experiments-have-a)

Suggestive

AGAINST

## The questions it answers

[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)

Open3 answers, none ahead

## Cite it

```
Mysteries Department. (2026). Methane is present near the surface at Gale at a background of a few tenths of a ppbv, with occasional… [Answer ANS0D7EXXYP7TFK]. https://mysteriesdept.com/r/ANS0D7EXXYP7TFK
```

Key

**ANS** 0D7EXXYP7TFK

Kind

Answer · hypothesis

Origin

Published

Version

1

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