The Largest Storm in Our Solar System Is Moving Unexpectedly, Scientists Say

Recent observations of Jupiter’s Great Red Spot (GRS) captured by the Hubble Space Telescope reveal that this colossal storm, which has persisted for nearly 190 years, behaves in unexpected ways. The GRS, the largest storm in the solar system—large enough for Earth to fit inside—has shown a surprising degree of instability, with new data indicating that it wiggles like gelatin and changes shape.

The Hubble's images, taken over 90 days from December to March, depict the GRS oscillating in size and movement. Lead study author Amy Simon, a planetary scientist at NASA’s Goddard Space Flight Center, noted that while researchers knew the storm’s longitude varied, they were surprised to find its size fluctuating as well. “This is really the first time we’ve had the proper imaging cadence of the GRS,” she said.

For over 150 years, astronomers have monitored this iconic storm, but its oval shape can appear skinnier or fatter, adding to its enigmatic nature. Additionally, the James Webb Space Telescope has provided infrared observations revealing that the GRS is cold at its center, causing ammonia and water to condense and form thick clouds.

The latest study, published on September 27 in the Journal of Geophysical Research: Planets, also detected phosphine gas within the storm, which could contribute to its distinctive red hue. NASA uses Hubble’s capabilities to track the GRS annually through the Outer Planet Atmospheres Legacy (OPAL) program. However, these new observations focused specifically on the storm's changes over several months.

According to coauthor Leigh Fletcher from the University of Leicester, the apparent stability of Jupiter's atmosphere belies its chaotic weather patterns, which are as complex as those on Earth. Understanding the dynamics of the GRS could shed light on atmospheric processes on exoplanets around other stars, expanding our grasp of weather phenomena beyond Earth. Simon concluded that daily variations in the storm’s characteristics are significant, highlighting the GRS's dynamic nature.