Since every planet spins at a different speed, the gears are built with different ratios: Earth takes about 24 hours to spin once, Mars takes about 24.6 hours, Jupiter spins much faster, and Saturn spins fast too. Because of this, each dial shows the real day cycle of that planet, so the clock doesn't calculate time digitally.
The gas giant's shape and size, previously known only from data collected more than 45 years ago, have been updated at last. The biggest planet in the Solar System just got smaller and flatter. Access Nature and 54 other Nature Portfolio journals Get Nature+, our best-value online-access subscription Subscribe to this journal Receive 51 print issues and online access $199.00 per year only $3.90 per issue. Prices may be subject to local taxes which are calculated during checkout.