by Estelle Asmodelle
The colours in this image were modified to emphasize the planetâ€™s atmospheric features. Neptuneâ€™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 planetâ€™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.