The new image was taken during summer in Saturn’s northern hemisphere as part of the Outer Planets Atmospheres Legacy (OPAL) project.
“Hubble found a number of small atmospheric storms,” said lead investigator Dr. Amy Simon, an astronomer at NASA’s Goddard Space Flight Center, and colleagues. “These are transient features that appear to come and go with each yearly Hubble observation.”
The atmosphere of Saturn is mostly hydrogen and helium with traces of ammonia, methane, water vapor, and hydrocarbons that give it a yellowish-brown color.
“Hubble photographed a slight reddish haze over the northern hemisphere in this color composite,” the researchers said. “This may be due to heating from increased sunlight, which could either change the atmospheric circulation or perhaps remove ices from aerosols in the atmosphere.”
“Another theory is that the increased sunlight in the summer months is changing the amounts of photochemical haze produced.”
“It’s amazing that even over a few years, we’re seeing seasonal changes on Saturn,” Dr. Simon said.
“Conversely, the just-now-visible south pole has a blue hue, reflecting changes in Saturn’s winter hemisphere.”
The rings of Saturn are mostly made of pieces of ice, with sizes ranging from tiny grains to giant boulders.
Just how and when the rings formed remains one of our Solar System’s biggest mysteries.
“NASA’s Cassini spacecraft measurements of tiny grains raining into Saturn’s atmosphere suggest the rings can only last for 300 million more years, which is one of the arguments for a young age of the ring system,” said team member Dr. Michael Wong, an astronomer at the University of California, Berkeley.