What do smoke rings, tornadoes and the Great Red Spot of Jupiter have in common? They are all examples of vortices, regions within a fluid (liquid, gas or plasma) where the flow spins around an imaginary straight or curved axis. Understanding how geophysical (natural world) vortices behave can be critical for tasks such as weather forecasting and environmental pollution monitoring.
Astronomers have at last discovered a nearby Earth-like planet that could easily have liquid water - and life.
Venus's rotation is slowing down - and scientists aren't at all certain as to why.
The ITU Radiocommunication Assembly has decided to hang on to the leap second for three more years, keeping the world's atomic clocks in synch with the Earth's rotation.
Last Friday's quake in Japan has likely shortened the length of the planet's day and shifted its axis, says a NASA scientist.