The most well-known feature on Jupiter is the Great Red Spot (GRS). It has been studied since at least 1831, though it could be older.
It is a huge anticyclone that is embedded in the South Equatorial Belt at 22 degrees south. The red cloud tops are about eight kilometers (five miles) above the belt clouds that surround the GRS, which appears to be the highest feature visible on Earth.
However, these cloud tops are only the tip of a much larger upwelling that draws material from as far below Jupiter's surface as 240 kilometers (149 miles). Infrared pictures show that material arriving at the surface structures a warm ring around a cooler 'eye' and edges where it upsets and starts to drop.
Like the color of Jupiter's belts, the spot's color is probably caused by the mixture of compounds it brings to the surface, but the chemistry behind its color is unknown. The intensity of the spot can vary a lot, and at times it can even hide completely, appearing only as a "hollow" in the cloud bands that surround it.
The GRS was formed by a similar process, according to comparisons with other storms that occasionally merge, expand, and deepen in color. It might not be immortal, despite its lengthy lifespan; Its east-west diameter has decreased significantly since the middle of the 20th century, and it is anticipated to become circular within a decade or two.
--Bhautik Thummar
