Saturn is one of the most beautiful planets in our solar system, with its wide ring system and colorful skies. NASA has been observing Saturn with the Hubble Space Telescope and watching the changing seasons on the massive planet. The telescope gave astronomers a look at the turbulent atmosphere as Saturn’s northern hemisphere, currently in summer, transitions into autumn.
The Three photos Below is Saturn in 2018, 2019, and 2020 from left to right. Planetary scientist Amy Simon of NASA’s Goddard Space Flight Center says the tiny changes to Saturn’s color ranges from year to year are startling. As the planet moves towards fall in the northern hemisphere, the polar and equatorial regions clearly alter the sequence of images.
Simon also notes that scientists are seeing that the planet’s atmosphere varies over much shorter timescales. The team found that a slight change in Saturn’s color from year to year could also indicate a change in cloud height and winds. However, the changes to the planet are not huge. Scientists expect major changes over the seasonal timescale, as current progress shows changes towards the new season.
Images from Hubble show that from 2018 to 2020, Saturn’s equator brightened by 5 to 10 percent, and the winds changed little. In 2018, winds measured near the planet’s equator reached about 1,000 miles per hour. Wind speeds were well above the 800 mph measured by NASA’s Cassini spacecraft from 2004 through 2009.
However, in 2019 and 2020, wind speeds returned to the 800mph range that Cassini had seen. Wind speeds also vary with altitude, which led scientists to believe that the speed measured could indicate that clouds in 2018 were about 37 miles deeper than those measured by Cassini. It should also be noted that it takes 29 years for Saturn to complete an orbit around the Sun, which means that each season of Saturn takes more than seven years.