Featured Image: A New Dark Vortex on Neptune


This remarkable series of images by the Hubble Space Telescope (click for the full view) track a dark vortex — only the fifth ever observed on Neptune — as it evolves in Neptune’s atmosphere. These Hubble images, presented in a recent study led by Michael Wong (University of California, Berkeley), were taken in 2015 September, 2016 May, 2016 October, and 2017 October; the observations have monitored the evolution of the vortex as it has gradually weakened and drifted polewards. Confirmation of the vortex solved a puzzle that arose in 2015, when astronomers spotted an unexplained outburst of cloud activity on Neptune. This outburst was likely a group of bright “companion clouds” that form as air flows over high-pressure dark vortices, causing gases to freeze into methane ice crystals. To learn more about what the authors have since learned by studying this vortex, check out the paper below.


Michael H. Wong et al 2018 AJ 155 117. doi:10.3847/1538-3881/aaa6d6