In the 1660s, Italian astronomer Gian Domenico Cassini made a groundbreaking discovery while observing Jupiter. He noticed a huge spot on the planet, which is now known as the Great Red Spot or Fixed Spot. This feature is believed to be evidence of a powerful Jovian storm. However, recent research suggests that the storm being observed today is not the same one that Cassini saw nearly four centuries ago.
What appears as a red dot from space is actually an anticyclonic vortex twice the size of Earth. The storm includes winds gusting up to 400 miles per hour, making it one of the most powerful natural phenomena in our solar system. The characteristic color of the spot may be due to interactions between elements in Jupiter’s atmosphere and different forms of radiation. Despite being known for centuries, scientists are still unraveling many mysteries about this fascinating celestial body.
Cassini was hailed as a pioneer of telescopic astronomy and first spotted the spot in 1665 as a dark oval shape. He noted that it appeared to be permanent and would often reappear in the same location with a consistent size and shape. Other astronomers documented sightings of this mysterious phenomenon until 1713 when sightings ceased for over two centuries. It wasn’t until 1831 that scientists again reported seeing this spot in the same location that Cassini had identified it in his observations.
A recent study published in Geophysical Research Letters used historical observations to track changes in size and movement of this famous cosmic phenomenon over time, comparing it to modern data. By simulating different scenarios, researchers concluded that today’s Great Red Spot looks more like its counterpart documented in the 1800s than what Cassini originally observed over three centuries ago. The spot has evolved over time, shrinking and becoming rounder due to increased rotation speed, probably caused by unstable winds that created an initial proto-storm that disappeared only to reappear later on Jupiter’s surface.
Lead researcher Agustin Sánchez-Lavega expressed his excitement about studying Cassini’s notes and drawings during his time at University of Basque Country in Bilbao Spain emphasized on quantifying previous research findings saying their work was both motivating and inspiring.
The Great Red Spot remains an enduring mystery for scientists who continue to study this fascinating celestial body with new technologies such as satellites and telescopes, shedding light on its complex history and future evolution on Jupiter’s surface.