4. Mercury is colder than Venus
As we all know, Mercury is the closest planet to the Sun and therefore, logically, it should be the hottest one, but that’s actually incorrect. Although Venus is twice as far away from the Sun as compared to Mercury, it is still the hottest planet. This is because of something with which we are all quite familiar – the ‘Greenhouse effect’. Mercury’s atmosphere is insignificant, so most of the heat from the Sun is reflected back into space by its surface, whereas the carbon dioxide-rich atmosphere of Venus traps heat and the planet’s temperature rises over time.
5. Venus rotates in the opposite direction
Most planets rotate on their axes in a counterclockwise direction, but Venus rotates clockwise at the slowest rotational speed of all the planets. Because its rotation is so slow, Venus is very close to being a perfect sphere. One Venusian year is only twice as long as one Venusian day.
6. Saturn can float on water
This is more like a weird fact than a mystery, but it’s still quite surprising to know that something as large as a planet would be able to float on water. Contrary to what most people think, the ability of a body to float on water does not depend on its weight, but rather on its density. If something is denser than water, then it will sink, and otherwise it will float. The average density of Saturn is less than that of water, thus making it possible for it to float on water. However, we would need a swimming pool 1300 times the volume of the Earth to test this interesting fact in person.
7. Ceres has more water than Earth
Ceres is a minor planet and the largest object in the asteroid belt. It is also the thirty-third largest object in the Solar System and is, interestingly enough, composed of ice and rock. Due to its sheer gravitational power, it is the only object in the asteroid belt that is rounded by its own gravity. While all this is pretty unique for a minor planet, the fact that helps it outshine its brethren is that the minor planet might have a remnant internal ocean of liquid water under a layer of ice.