Scientists found a secret in old Voyager 2 data. This is why we need to revisit Uranus and Neptune

By Ashley Strickland, CNN

Updated 1910 GMT (0310 HKT) March 27, 2020

NASA's Voyager 2 spacecraft visited Uranus (left) in 1986 and Neptune (right) in 1989.
Photos: Voyager 2 captures planetary portraits
NASA's Voyager 2 spacecraft visited Uranus (left) in 1986 and Neptune (right) in 1989.
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Voyager 2 launched on August 20, 1977. Retrace the steps of its journey across our solar system through some of its most iconic images.
Photos: Voyager 2 captures planetary portraits
Voyager 2 launched on August 20, 1977. Retrace the steps of its journey across our solar system through some of its most iconic images.
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Voyager 2's view of Jupiter during the spacecraft's approach.
Photos: Voyager 2 captures planetary portraits
Voyager 2's view of Jupiter during the spacecraft's approach.
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Voyager 2 provided this image of Jupiter's red spot.<br />
Photos: Voyager 2 captures planetary portraits
Voyager 2 provided this image of Jupiter's red spot.
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The hemisphere of Ganymede that faces away from the Sun displays a great variety of terrain in this mosaic from NASA's Voyager 2.
Photos: Voyager 2 captures planetary portraits
The hemisphere of Ganymede that faces away from the Sun displays a great variety of terrain in this mosaic from NASA's Voyager 2.
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A mosaic of Europa, Jupiter's smallest moon, shows bright areas, likely ice deposits, and darker areas that may be the rocky surface or areas with a more patchy distribution of ice. The most unusual features are systems of long linear structures that cross the surface in various directions, some of which are more than 1,000 kilometers long and about 2 or 3 kilometers wide.
Photos: Voyager 2 captures planetary portraits
Images from Voyager 2 – A mosaic of Europa, Jupiter's smallest moon, shows bright areas, likely ice deposits, and darker areas that may be the rocky surface or areas with a more patchy distribution of ice. The most unusual features are systems of long linear structures that cross the surface in various directions, some of which are more than 1,000 kilometers long and about 2 or 3 kilometers wide.