What Is The Great Red Spot?

QUICK ANSWER

The Great Red Spot is a giant storm on Jupiter that has been raging continuously for at least 350 years. It's currently about 10,000 miles wide, big enough to swallow Earth, with winds reaching up to 400 mph. The storm has been gradually shrinking over the past century.

The Great Red Spot is the longest-running storm humans have ever observed. It's older than the United States, possibly older than the telescope itself, and it shows no obvious sign of stopping. The storm is also slowly getting smaller, which is the part nobody expected.

What is the Great Red Spot exactly?

A massive anticyclonic storm in Jupiter's atmosphere, spinning counter-clockwise in the planet's southern hemisphere. According to NASA, the storm has been observed continuously for at least 200 years, and possibly since the 1660s. Unlike Earth's hurricanes, which form and dissipate within weeks, the Great Red Spot has somehow remained stable for centuries. Wind speeds at its edges can reach about 400 mph, far stronger than any Earth storm.

How big is the Great Red Spot?

Currently about 10,000 miles wide, large enough to fit Earth inside it. That's substantially smaller than it used to be. Historical observations show the storm was about 25,000 miles wide in the late 1800s, and it has been gradually shrinking ever since. The shape has also changed from oval to more circular over the past decade. The reason for the shrinkage isn't fully understood, but the trend has been consistent for over a century.

Why is the Great Red Spot red?

The exact cause isn't fully settled. The reddish color likely comes from chemical compounds in Jupiter's upper clouds, possibly including sulfur, phosphorus, or organic molecules called tholins, formed when sunlight breaks down ammonia and other gases in the upper atmosphere. The color isn't constant; the Great Red Spot can appear pale pink, deep brick red, or somewhere in between, and the variations may be linked to weather patterns deeper in Jupiter's atmosphere.

Will the Great Red Spot ever disappear?

Possibly. If the shrinking continues at its current rate, the storm could become significantly smaller over the next century, though whether it would actually dissipate is uncertain. Some scientists think the Great Red Spot may shrink to a stable smaller size rather than vanishing entirely. Computer models of Jupiter's atmosphere suggest that storms of this kind can persist for very long periods because there's no land or coastline to disrupt them. Earth's storms break apart over continents; Jupiter has nothing for storms to crash into.

The Great Red Spot is the longest-running weather event humans have observed, a storm bigger than Earth that has been spinning continuously for centuries. It's slowly getting smaller, but at the current rate, it will probably be around for a long time. Jupiter's atmosphere is a different game than Earth's, and the storms reflect that.

What Is The Great Red Spot?