(CNN) The weather on Jupiter and Uranus is changing gradually, according to our galaxy’s own interplanetary meteorologist.
NASA’s Hubble Space Telescope captured Earth’s outer planetary neighbors in images from 2014 to 2022, documenting changes in the planets’ weather and seasons over time.
In Jupiter at about 484 million miles (779 million kilometers) away from our sun and Uranus about 1.8 billion miles (3 billion kilometers) apart, each takes longer to orbit the sun, which means the seasons move more slowly. But the gas giants are still experiencing extreme weather. That’s especially true for Uranus, which has a strange, tilted axis that causes one hemisphere to be completely without sunlight for about 42 years at a time.
In the November 2022 Hubble image of Uranus, the planet’s north pole has a large white circle, caused by a thick photochemical haze that resembles the smog produced by cities, along with several storms near the edge of the circle, according to NASA.
In one of the first images from the Outer Planet Atmospheres Legacy, or OPAL, Program of the Hubble Space Telescope, the north polar cap of Uranus appears brighter than it did in a November 2014 image. A NASA research team is monitoring the size and brightness of the north polar cap and reports that the haze appears to lighten each year.
“I always had a view of the planets when I was young that they were very static. You have a picture in the textbook; you never saw them change. And of course, that’s not true. These are huge atmospheres, they change everything of time,” said Dr. Amy Simon, the senior scientist for Planetary Atmospheres Research at NASA, who was involved in these Hubble observations.
“For us to understand the processes that are going on, we just need more time coverage. A year on Jupiter takes 12 Earth years, and it only gets worse from there. We’re trying to build this database so we can understand the processes occurring in these atmospheres.”
Monitoring atmospheric changes
The goal of the OPAL project is to obtain observations of the outer planets to help scientists better understand theirs dynamics and evolution of the atmosphere. Since following Uranus’ polar cap and how it changes with the seasons, scientists have discovered that neither pole is bright during the planet’s equinox in 2007, when it is fully illuminated by the sun.
In 2028, when the northern summer solstice approaches, NASA scientists predict that the cap will grow even further, giving Hubble a clear view as the north pole of Uranus points directly at Earth.
“If you think about the original Voyager images of Uranus, it’s just a pale blue empty ball. You didn’t see any clouds, you didn’t see any haze, you didn’t see anything … so there was a polar cap, but we couldn’t see it,” Simon said. “What we were watching. over time (using Hubble), is it the build-up of this high-altitude haze in the atmosphere, and the exact purpose or the exact mechanism behind it, we don’t know, is that one of the things we’re studying .”
Great Red Spot storm system
In a January image of Jupiter, the planet’s Great Red Spot is in the limelight. The site, which is actually a giant, centuries-old storm, is located next to one of Jupiter’s moons, called Ganymede. It is the largest moon of the solar system and is slightly larger than the planet Mercury.
This Hubble image shows that the Great Red Spot is big enough to swallow Earth, according to NASA.
Although the vortex is very powerful, scientists have observed that the area has been shrinking over the years and reported that it is at its smallest size, according to records including data dating back 150 years.
Jupiter’s increased storm activity
At the Hubble launch in 1990, no storms or thunderstorms were seen on Jupiter. But over the past decade, storms have increased, with a succession of storms seen in both images in November 2022 and January 2023. If the storms are close to each other, they can merge and possibly form a huge storm that is even bigger. than the size of the Great Red Spot, according to NASA.
“We’re used to seeing a lot of big changes on Jupiter. We see clouds change color, we see storms coming, we watch the Great Red Spot — I want to see a big storm outbreak on Uranus, because that’s one of the few places where we don’t see that often,” Simon said. “If we see a big storm forming on Uranus (using Hubble), I’m pretty excited.”
With Hubble, scientists can closely monitor the changing environments of these outer planets. “Hubble’s intelligence and sensitivity keep an unblinking eye on a kaleidoscope of complex activities over time,” according to a NASA statement.