Length of a Day on Neptune Finally Established

Astronomers were recently able to determine that a day on the gas giant Neptune lasts for 15 hours, 57 minutes and 59 seconds. Scientists have been trying to figure this out for many years, but thus far their studies have been stifled by lack of accurate data.

In order to arrive at the new conclusions, a group of investigators had to use a wealth of data collected by the NASA Hubble Space Telescope and American space agency's Voyager 2 probe. More than 500 images were combined to create a time-lapse video of a full day on Neptune.

Establishing the length of day on gas giants is a very complex process primarily because astronomers cannot see the planets' surface. Their atmospheres usually spin either faster or slower than the actual ground mass, making it hard to verify whether predictions are correct or not.

Previous studies have established a day on Neptune to last for 16 hours and 6 minute, but the new data refine the results even further, and slightly decrease this amount.