Methane Fuels Superstorms on Uranus and Neptune

Scientists have finally discovered why intense superstorms occasionally erupt on Uranus and Neptune, and the key ingredient is methane. These distant ice giants, rich in water, experience massive, short-lived storms that can be seen from Earth. For years, researchers have been puzzled by the irregular nature of these storms. Now, a team of astronomers suggests that methane is responsible for these unpredictable events.

Normally, heat from a planet’s interior rises to the surface, cooling and causing turbulence, which can trigger storms. However, the constant warmth inside Uranus and Neptune and their cool exteriors raise the question: why aren’t storms always happening? According to a paper on arXiv, methane, the third-most abundant molecule in these planets’ atmospheres, plays a crucial role.

In the upper atmosphere, methane condenses into droplets that fall to lower altitudes, where they reheat and rise again, forming a cycle similar to Earth’s water cycle. Once the atmosphere becomes saturated with methane, a stable layer forms, preventing heat from reaching the surface and thus suppressing storm formation. This methane layer is common on Neptune and certain parts of Uranus, but at Uranus’ poles, the lack of methane allows heat to rise easily, resulting in larger storms.

On Neptune, methane occasionally escapes from the stable layer, allowing heat to flow and storms to form before the atmosphere settles again. Further research will help scientists understand these complex atmospheric interactions and provide insights into planets beyond our solar system.