The expression “the days are long but the years are short” is usually applied to the challenging yet fleeting experience of parenthood, but in a literal sense, it more accurately describes the marking of time on the planet Venus.
The second-closest planet to the sun takes nearly 225 Earth days to complete one orbit, compared to Earth's 365 days. Venus orbits the sun at around two-thirds the distance between the sun and the Earth.
However, the nature of a Venusian day is where things get strange. Compared to Earth’s counterclockwise rotation on its axis, Venus spins “backward” in a clockwise direction in retrograde rotation, so if you were standing on Venus, you would see the sun rising in the west and setting in the east. However, you’d have to be extremely patient to observe this. The planet completes one rotation on its axis every 243 Earth days, which is the slowest of any planet and notably longer than it takes Venus to orbit the sun.
Recent research by University of California, Riverside astrophysicists suggests that the dense, stormy atmosphere on Venus contributes to the sluggish pace of the planet’s rotation. Venus experiences an extreme version of the greenhouse effect, with sulfuric acid clouds and an atmosphere mainly composed of carbon dioxide causing temperatures to reach 900 degrees F (475 degrees C). The top layer of this fast-moving atmosphere whips around the planet every four (Earth) days.
The researchers theorize that the fast, powerful winds on Venus (they can reach speeds of 224 mph, or 360 km/h) create drag in the atmosphere and lessen the impact of the sun’s gravity. This may explain why mathematical models indicate that Venus should have taken 6.5 million years to get tidally locked with the sun, yet this has not fully happened, even after 4.5 billion years.
Rotating oddities:
- Although Mercury is closer to the sun, Venus is the hottest planet in the solar system. Due to the unimaginably high temperatures (it’s hot enough to melt lead) and a surface covered in volcanoes, it’s no surprise that Venus has been nicknamed Earth’s “evil twin.”
- Venus is roughly the same size as Earth and has the closest approach, though Mercury spends the most time closest to Earth due to its small orbit and proximity to the sun.
- Our moon is tidally locked in synchronous rotation with the Earth due to the gravitational influence of our planet, which results in our natural satellite completing an orbit around the Earth in sync with a rotation on its axis. This is why we only ever see one side of the moon from Earth, despite its constant rotation.
