Terraforming of Venus begins, “the most expensive publicity stunt in recorded history.” Rumors of life in Venus’s clouds and acid pools circulate.
Reference: HSD 2.0 Venus history
Date Notes: There’s a lot of ambiguity here, HSD 2.0 established this date as early 400 but in 1.0 it was tied into the difficult-to-date IRPF origin story and pirate age, with about 50 years of wiggle room on either side.