Astronomers explain 1,800 km long mysterious cloud on Mars

Researchers have proposed a new explanation for the Arsia Mons Elongated Cloud (AMEC), a massive white ice formation on Mars that stretches approximately 1,800 km in length. The cloud appears near the Arsia Mons volcano at an altitude of about 45 km during the Martian spring and summer in the southern hemisphere.

A study led by Jorge Hernández-Bernal from Sorbonne Université utilized computational atmospheric models to understand the phenomenon. The findings, published in Nature Geoscience, suggest the cloud forms through a physical process involving extreme water vapor saturation that does not rely on the usual presence of dust particles to trigger ice formation.

Unlike clouds on Earth, which typically require dust or salt particles to form ice crystals, the AMEC appears to be driven by exotic physics. The researchers noted that while these physical concepts exist in textbooks, they are often considered theoretical and have not been observed in action within a planetary atmosphere until now.