by Estelle Asmodelle
The colours in this image were modified to emphasize the planet’s atmospheric features. Neptune’s Great Dark Spot stands out as the most prominent feature on the left. The two key features Karkoschka used can also be seen: the fainter Dark Spot 2 and the South Polar Feature, which are locked to the planet’s rotation.Credit: Erich Karkoschka
TUCSON: The first accurate measurement of Neptune’s rotational period has been determined by tracking specific atmospheric features. A day on Neptune lasts precisely 15 hours, 57 minutes and 59 seconds.
This finding adds to our knowledge of the fundamental properties of Neptune and also provides a mechanism for understanding how Neptune’s mass is distributed. The study could lead to a better understanding of the giant gas planets in general.