While vortices on Neptune have been spotted several times before, dating back to the 1989 flyby of ‘Voyager 2’, this recent Hubble observation marks the first time the phenomenon has been seen in the 21st century.
They’re known to travel with what are referred to as bright “companion clouds” that are probably made up of methane ice crystals.
Scientists believe that these clouds are created by gases that freeze when currents of air surrounding the vortices are disturbed and pushed above it.
He said that Neptune’s dark vortices float through its atmosphere like “huge, lens-shaped gaseous mountains.”
Wong compared these companion clouds to flat (orographic) clouds that can form over mountains here on Earth.
Scientists say the size, shape and stability of Neptune’s dark vortices can change, and that they can wander in the atmosphere, traveling at speeds that can vary from slow to fast.
NASA says future observations and investigations could provide scientists with a better understanding of how the vortices are created, what causes them to drift through the atmosphere, their relationship with Neptune’s environment as well as what causes them to eventually disperse.
Meanwhile, the space agency says it has just extended a contract that makes it possible to continue the science operations of the Hubble Space Telescope for another five years to 2021.
This extension would allow a bit of an overlap in operations between the Hubble and its more sophisticated successor, the James Webb Space Telescope, which is scheduled for launch in 2018.