(CNN) - A giant storm that was once as wide as the Atlantic Ocean is gently fizzling out 3 billion miles away from Earth, on the planet Neptune.
Images from the Hubble Telescope show the storm has been shrinking since it was first seen in 2015.
Scientists thought it would head to Neptune's equator and break up, creating a spectacular outburst of cloud activity.
Instead of going out with a bang, the dark vortex surprised researchers by drifting to the south pole where it is dying with a whimper.
Neptune's immense storms were first discovered by NASA's Voyager 2 spacecraft in the 1980s.
Only the Hubble has the necessary blue light sensors to track them.
Two other dark storms Hubble saw in the 1990s also vanished.
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