> Which planet in our solar system spins the slowest, completing a full rotationonce every 243 Earth days?And the answer: Venus. As the second planet from the sun, Venus completes one rotation every 243 Earthdays. In other words, one day on Venus equals 243 days on Earth. That's by farthe slowest rotation of any planet in our solar system.Heavenly Neighbours © Saber Karimi.You may think you know just about everythingthere is to know about our neighboring planet, Venus, but this curious sister ofEarth has tricks around every corner. Test your knowledge below.Q: Which planet is hotter: Mercury or Venus?A: Venus! Despite being further away from the sun than Mercury, the high amountsof carbon dioxide in Venus' atmosphere create an incredibly inhospitableatmosphere. Its mean temperature is around 863 degrees Fahrenheit. Whew!Q: Does Venus have a higher or lower atmospheric pressure as compared to Earth?A: Higher. Much, much higher in fact. Venus has 90 times the atmosphericpressure of Earth. Q: Who is Venus named after?A: The Roman goddess of love and beauty. It's thought that Venus was named forthe goddess of beauty due to her brilliant shine in the night sky. Of the fiveplanets known to ancient astronomers, it would have been the brightest.Q: After the moon, which object in our solar system shines the brightest in thenight sky?A: And again... Venus! Venus' clouds of sulfuric acid make it incrediblyreflective in the daytime and at night. They don't call it the morning andevening star [https://www.askqotd.com/the-morning-and-evening-star/] fornothing!Learn more about our twin planet below.