
It may sound like an April Fool’s joke about flatulent aliens, but this is serious: The scientists behind the European Space Agency’s Mars Express orbiter think they know where a smelly outburst of Martian methane came from.
Any joke would fall flat, because the proposed explanation is purely geological rather than, um, biological.
The source of Martian methane has been a mystery for 15 years, thanks in part to earlier findings from Mars Express.