News by Levels · Level 3 · Student worksheet

Gas Over Martian Fissures Points to Possible Volcanism

In this lesson: Separate the favoured explanation from confirmation of present-day volcanism.

Name: __________________________ Date: __________________

Read the story

Scientists analysing data from the ExoMars Trace Gas Orbiter have reported traces of hydrogen chloride above fissures on the northern flank of Alba Mons, a broad Martian volcano. The European Space Agency discussed the study on November 4.

The team compared atmospheric measurements with images of the surface and assessed possible explanations. Co-author Daniel Mège told the agency that seepage linked to magma appeared more likely than the other sources they examined.

If confirmed, the interpretation would suggest that heat below the surface may still support volcanic processes. Researchers have not observed a present-day eruption or flowing lava on Mars, so the detection is a clue rather than direct proof of one.

Source: European Space Agency, 2026-11-04. https://blogs.esa.int/to-mars-and-back/2026/11/04/geological-intuition-for-mars/

Read and practise

1. Which explanation did Daniel Mège consider more likely among those examined?

   1. A directly observed new lava flow
   2. An explanation already proved by a surface rock sample
   3. Seepage linked to magma

2. Why does the article call the detection a clue rather than direct proof of a present-day eruption?

   1. The spacecraft detected no gas at all
   2. The team did not examine the surface
   3. No present-day eruption or flowing lava has been observed

Your turn

Distinguish the observed evidence from its proposed explanation and state what remains unobserved.

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Read online: https://newsbylevels.com/news/mars-alba-mons-hydrogen-chloride-volcanism-november-2026/level-3/