A dramatic new time-lapse movie by the Hubble telescope shows for the first time seasonal changes on the planet.

Once considered one of the blander-looking planets, Uranus is now revealed as a dynamic world with the brightest clouds in the outer solar system and a fragile ring system that wobbles like an unbalanced wagon wheel.

The clouds are probably made of crystals of methane, which condense as warm bubbles of gas well up from deep in the planet's atmosphere.