Have you ever noticed that wind and weather patterns tend to travel in the same general direction? While there can be some local changes to this for various reasons, the atmosphere on Earth typically travels in the same overall direction as the rotation of the Earth. This makes sense because the Earth is pulling the atmosphere along. The same thing can be seen on other bodies in our solar system that have atmospheres.

There is, however, one exception to this. Titan, which is the largest moon orbiting Saturn, doesn’t follow this rule, and researchers can’t figure out why.

Titan’s orbit has a very small tilt of just .3 degrees off of its plane of orbit around the sun. This is tiny compared to the tilt of the Earth, which is at 23.45 degrees, and even further off the tilt of Saturan, which is 26.7 degrees.

With that level of tilt, researchers expected the atmosphere of this moon to travel at roughly the same angle, but they found that this wasn’t the case. Dr. Lucy Wright is the lead author of the study published on this. She is from the University of Bristol, and recently talked with IFLScience about this anomaly, saying:

“It seems that the angular momentum axis of the atmosphere is offset from that of the solid body. Over time, the rotation axis of the atmosphere is changing relative to the planet’s spin-axis.”

This study, which is published in the Planetary Science Journal, is based on 13 years of observations that were gathered during the Cassini mission. The team found that the atmospheric temperature is also not located at the poles of the moon as they predicted. Wright explained in a statement:

“The behaviour of Titan’s atmospheric tilt is very strange. Titan’s atmosphere appears to be acting like a gyroscope, stabilising itself in space. We think some event in the past may have knocked the atmosphere off its spin axis, causing it to wobble. Even more intriguingly, we’ve found that the size of this tilt changes with Titan’s seasons.”

While the team is able to describe the abnormality in the paper, they haven’t been able to come up with a good explanation at this time. Professor Nick Teanby is the co-author of the study and he says:

“What’s puzzling is how the tilt direction remains fixed in space, rather than being influenced by the Sun or Saturn. That would’ve given us clues to the cause. Instead, we’ve got a new mystery on our hands.”

Additional missions are planned for this part of space in the future, including the Dragonfly mission, which is set to visit Titan in 2034 and will hopefully gather information to start answering these questions.

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