Did you know that Venus is upside down?
Expand your mind with these top eight facts about the planet Venus.
It takes Venus longer to rotate once on its axis than to complete one orbit of the Sun. That’s 243 Earth days to rotate once – the longest rotation of any planet in the Solar System – and only 224.7 Earth days to complete an orbit of the Sun.
Its mean temperature is 462°C. This is because of the high concentration of carbon dioxide in Venus’ atmosphere, which works to produce an intense greenhouse effect. Heat is trapped in the atmosphere like a blanket, causing the temperature of the planet to be much higher than its proximity to the Sun would suggest.
All other planets spin anti-clockwise on their axis and orbit the Sun in an anti-clockwise direction. Venus also orbits the Sun anti-clockwise, but its unusual axis rotation is due to being upside down – it was knocked off its upright position earlier in its history!
Astronomers believe that at some point, a colliding celestial body tilted Venus so far off its original position that it is now upside down. The only other planet to spin in a weird direction is Uranus which spins on its side, probably the result of another collision early on in its life.
The clouds of sulphuric acid in Venus’ atmosphere make it reflective and shiny, obscuring our view of its surface. Its brightness makes it visible even during the day – if it’s clear and you know where to look.
That’s about the same as the pressure found at a depth of 1km in the Earth's oceans.
It is thought that Venus was named after the beautiful Roman goddess (counterpart to the Greek Aphrodite) due to its bright, shining appearance in the sky. Of the five planets known to ancient astronomers, it would have been the brightest.
Because Venus is easy to spot with the naked eye, it is impossible to say who discovered the planet. But over the centuries we have been able to measure Venus’ motions, including the rare transit of Venus, when the planet appears to cross in front of the Sun.
Following the rules of Latin, we should say ‘venerean’ as the adjective to describe things related to Venus. However, this is deemed to be too close to the word ‘venereal’. The more commonly used word is ‘Venusian’ despite its clunky etymology.
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Main image courtesy of NASA