Short answers, pulled from the story.
Jupiter formed just one million years after the Sun, roughly 50 million years before Earth came into existence. Current models suggest this massive planet began its life at or beyond the snow line where temperatures were cold enough for volatiles like water to condense into solids.
Jupiter's atmosphere consists of 76% hydrogen and 24% helium by mass with trace amounts of carbon oxygen sulfur neon ammonia water vapor phosphine and hydrocarbons. The outermost layer contains crystals of frozen ammonia floating above cloud layers located in the tropopause region.
The Great Red Spot stands as a persistent anticyclonic storm located 22 degrees south of the equator that rotates counterclockwise every six days. Its maximum altitude reaches about 200 kilometers above surrounding cloud tops while Juno measured its depth at around 350 kilometers by October 2021.
Automated spacecraft have visited Jupiter since the 3rd of December 1973 when Pioneer 10 passed within 130,000 kilometers. Six years later Voyager missions vastly improved understanding of Galilean moons while discovering Jupiter's rings.
In 1610 Italian polymath Galileo Galilei discovered four largest moons using a telescope marking the first telescopic observation of moons other than Earth's. Just one day later Simon Marius independently found these same moons though he did not publish until 1614.