# The rover's methane readings are an instrumental artefact, chiefly methane leaking from the foreoptics…

> Still possible: The rover's methane readings are an instrumental artefact, chiefly methane leaking from the foreoptics chamber into the sample cell.

Source: https://mysteriesdept.com/mysteries/mars-methane/answers/ANS0D7EXZNC60BA/the-rovers-methane-readings-are-an-instrumental-artefact  
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

# The rover's methane readings are an instrumental artefact, chiefly methane leaking from the foreoptics…

The rover's methane readings are an instrumental artefact, chiefly methane leaking from the foreoptics chamber into the sample cell.

**Still possible** Answers **1** questionPublished0

## Where it stands

**Still possible** Its tests haven't settled it: two pieces of evidence for, one against. It needs two reviews to be accepted.

## What it predicts

- Cell methane correlates with foreoptics methane and pressure changes.
- Fitting the full triplet pattern rather than averaging lines removes or reduces the signal.
- The orbiter continues to see no methane at any altitude it can reach.

## What would rule it out

- A controlled test showing no transfer from foreoptics to cell, together with an independent surface instrument confirming methane.

## Evidence 2 for · 1 against

[The orbiter's limits near Gale are up to four times below the rover's background for the same season.](https://mysteriesdept.com/mysteries/mars-methane/evidence/EVD0D7EY0500VW6/the-orbiters-limits-near-gale-are-up-to-four-times-below-the)

Supported

FOR

[Unreported diffusion experiments give a gas-transport coefficient that makes small leaks plausible.](https://mysteriesdept.com/mysteries/mars-methane/evidence/EVD0D7EXZX64X5N/unreported-diffusion-experiments-give-a-gas-transport)

Suggestive

FOR

[A strong day-night difference is not an obvious product of a leak.](https://mysteriesdept.com/mysteries/mars-methane/evidence/EVD0D7EY0CT140X/a-strong-day-night-difference-is-not-an-obvious-product-of-a)

Speculative

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). The rover's methane readings are an instrumental artefact, chiefly methane leaking from the foreoptics… [Answer ANS0D7EXZNC60BA]. https://mysteriesdept.com/r/ANS0D7EXZNC60BA
```

Key

**ANS** 0D7EXZNC60BA

Kind

Answer · hypothesis

Origin

Published

Version

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