With these images, scientists can study how these weather changes impact each planet.
NASA's long-lived Hubble telescope spotted a notable storm churning inside the planet's blue-green atmosphere, and the space agency posted the image online Thursday. Uranus, which is in its summer season, also has a more prominent polar-cap region that might be a result of atmospheric flow changes. That constant sunlight may be affecting the planet's atmosphere, forming what NASA calls a 'polar hood, ' which we see as a mass of frosty white clouds.
The space agency also spotted a new storm brewing on Neptune.
"The yearly observations are helping us to understand the frequency of storms, as well as their longevity", Amy Simon, a scientist at NASA's Goddard Space Flight Center who leads the OPAL mission, told Gizmodo.
Like Earth, Uranus and Neptune have seasons, which likely drive some of the features in their atmospheres, according to the U.S. space agency. The new data, captured during the autumn of 2018, are providing important new insights into the seasonal variations on both Neptune and Uranus.
Since 1993, Hubble has detected four more of the storms, including the latest one, which appeared in a routine image sweep in September 2018. Since then, only Hubble has had the sensitivity in blue light to track these elusive features, which have appeared and faded quickly.
Hubble uncovered the latest storm in September a year ago in Neptune's northern hemisphere.
The frosty planet can be seen with a massive white cap dominating its northern pole, and as NASA explains in a new blog post its odd appearance is actually owed to its freakish orientation.
"These clouds are similar to clouds that appear as pancake-shaped features when air is pushed over mountains on Earth (though Neptune has no solid surface)", the STScI said.
Earth is a bustling hub of weird life forms, Jupiter is a massive ball of gas with storms that could swallow other planets whole, and Uranus, well, Uranus is just plain weird.
The Hubble observations show that as early as 2016, increased cloud activity in the region preceded the vortex's appearance. Researchers suspect that the storms creep upward through the planet's atmosphere, lifting the ingredients of deeper layers of the atmosphere to the top.
This image, taken by Hubble's Wide Field Camera 3 (WFC3), reveals a vast bright stormy cloud cap across the north pole of Uranus. The band circles the planet just north of the equator and it remains a mystery for scientists just how bands like these form on Uranus and Neptune since both planets have dominant jets of westward blowing wind that are generally very broad.
Thanks to the extreme tilt of Uranus-the planet spins almost completely on its side-the Sun shines nearly overhead relative to Uranus's north pole in the summertime and doesn't set for decades. This leaves the sun shining non-stop onto its north pole during its long summer, likely resulting in widespread atmospheric changes. The exact causes of these aerosol changes, he said, remain a mystery, with possibilities including warming temperatures, unusual chemistry, some large-scale atmospheric circulation pattern, or a combination of all these.