Venus Rotates Backwards

On nearly every planet in our solar system, the sun rises in the east and sets in the west, but Venus is a remarkable exception. It spins clockwise on its axis in what scientists call a retrograde rotation, making it the lone dissenter among the planets (though Uranus is tilted so far on its side it almost rolls). This backward spin is incredibly slow. A single Venusian day, from one sunrise to the next, lasts a staggering 243 Earth days. In a bizarre cosmic twist, this means its day is actually longer than its year, which it completes in just 225 Earth days.

The exact cause of this planetary oddity remains a mystery, but scientists have compelling theories. One leading hypothesis suggests that early in its history, Venus was struck by a massive object, perhaps another protoplanet. Such a cataclysmic impact could have been powerful enough to not just halt its original spin but completely reverse it. Another possibility involves the planet's incredibly dense atmosphere. Over billions of years, the thick, heavy clouds could have created powerful tidal forces and atmospheric drag, gradually slowing Venus's rotation to a crawl before starting it up again in the opposite direction. Whatever the cause, this unique rotation contributes to the planet's extreme and inhospitable environment.