Leda in reality is a tiny moon of Jupiter discovered in 1974. But in a sense we can say that it was foreseen, because the use of the name "Leda" for a minor Jovian moon was anticipated in an Edmond Hamilton story published as long ago as 1945, well back in Old Solar System days, allowing us to string the precocious fiction along with the later reality on an identity-thread every bit as firm as that of OSS Jupiter itself...
Captain Future sprang to the port-hole windows. He looked down on the nighted jungles that covered this side of Leda.
Those weirdly beautiful jungles were flower forests! Instead of trees, gigantic flowers towered on massive stalks to a height of a hundred feet. Huge, waving moon lilies, great flame roses whose blooms were thirty feet in diameter, enormous, nodding orchids - their dense thickets lay in the silvery light of great Jupiter like a vast garden planted by giants.
Several of Jupiter's smaller moons possessed such flower forests, due to an excess of carbon dioxide in their atmosphere. But the great flower jungles of this moon Leda were the wildest and most beautiful of all.
Captain Future glimpsed the torpedo-shaped bulk of a small space-cruiser on the ground, half-hidden amid towering flame roses. Men were running toward the ship in alarm... [Outlaw World, p.26]
It's all to do with a three-cornered clash between the Futuremen, Bork King's Martian outlaws and Ru Ghur's raiders - and although we see a bit more of Leda in the following pages, including one of its giant spiders, the fascinating little world does not reveal many of its secrets in this book.
But we have been given a glimpse.
Edmond Hamilton, Outlaw World (1945)