The outer planets of our solar system – Jupiter, Saturn, Uranus, and Neptune – have no solid surfaces, instead consisting of swirling clouds of gases with their own seasons and storms. The Hubble Outer Planet Atmospheres Legacy (OPAL) program has been tracking these planets since 2014 to understand their unusual weather patterns.
For the past decade, OPAL has observed various phenomena on the outer planets, from Jupiter’s shrinking Great Red Spot storm to Saturn’s changing colors. These observations have contributed to over 60 scientific publications and are expected to provide more insights into the atmospheres of these distant worlds.
“We’ve been observing the outer planets for 10 years now, and our database is growing rapidly,” said Amy Simon, a planetary scientist at NASA’s Goddard Space Flight Center. “The data from OPAL has shown us many interesting features in the clouds of Jupiter, Saturn, Uranus, and Neptune.”
Jupiter, which lacks seasonal variability due to its slight axial tilt, still experiences intense storms like the Great Red Spot. The size and shape of this storm have been tracked by Hubble, revealing oscillations that cause it to shrink over time.
Saturn’s seasons are around seven years long and result in significant changes in the planet’s atmosphere. OPAL has observed subtle color changes, which may be connected to wind patterns and cloud formations.
Uranus, with its 42-year seasonal cycles, features a photochemical haze covering its northern pole that switches between periods of sunlight and shadow due to its unique rotation. Hubble has studied this phenomenon for years, but the exact controls on its seasonal changes remain uncertain.
Neptune, the farthest planet from the sun, is also under OPAL’s scrutiny. The program has tracked various storms and cloud formations, as well as observed changes in Neptune’s weather patterns over 40-year seasons. These observations will help scientists better understand the atmospheric dynamics of these distant worlds.
By studying the outer planets’ clouds and atmospheres, the OPAL program is providing valuable insights into the complex weather systems of our solar system.
Source: https://www.discovermagazine.com/the-sciences/a-decade-of-observation-decodes-the-storms-of-the-outer-solar-system