Meteorologists have grown used to trusting neural networks: the GraphCast model predicts Earth's weather days ahead by drawing on global snapshots of the atmosphere. But this 'brain' can be transplanted to another planet — where the air is thin and the Sun warms differently. The authors took GraphCast and fed it data from the Mars Climate Database, a sort of virtual twin of the Red Planet.
The first test, without fine-tuning, surprised them: the model produced a fairly accurate portrait of current weather, simply relying on its Earthly 'habits.' But look a day ahead, and the forecast drifted toward an average climate, losing the daily rhythm. Morning, noon, evening, and night blurred into one endless, averaged picture.
So they retrained the model from scratch. In just ten training cycles, it grasped the essentials: how the daily cycle unfolds, how temperature distributes across altitude layers. After a few dozen epochs, a ten-day forecast matched real Martian dynamics quite well. Quality improved with more data and depended on which season the prediction started from.
This experiment is more than a curiosity. Fast, accurate Martian weather forecasts would help plan rover operations, shield equipment from dust storms, and, eventually, support crewed missions.
Because of the low pressure, even a hurricane-force Martian wind would feel like a gentle breeze: it wouldn't knock you over, but it would kick up clouds of fine dust.
In Andy Weir's 'The Martian,' the astronaut survives by relying on precise weather reports — models like this could have been his electronic meteorologist.