Mercury is both the solar system’s smallest planet and the planet closest to the Sun. It’s relatively easy to see before sunrise or at dusk and has been known about since ancient times. It also orbits the Sun in just 88 days, earning it the name the Swift Planet. Let’s find out some more cool facts about Mercury.
1: Who does the planet Mercury represent?
In Roman mythology, Mercury was a very busy god of commerce, wealth, eloquence, messages, travelers, luck, trickery, and thieves, whose other responsibilities included conveying the dead to the underworld. With so many duties and delegations, it was necessary that he be remarkably fast and capable of flight. Naturally, Mercury’s name has also become associated with a great many things fast.
Examples include a liquid metal that moves so fast it is sometimes called quicksilver. A line of cars used to be named after him, and in the DC comic books, the original Flash wore the same metal winged type helmet that Mercury is often seen wearing after the superhero received his powers from the Greek god equivalent himself, Hermes. His name was also given to the fastest moving of the planets, our topic for today, Mercury!
2: How fast is the speed of Mercury?
And when I say fast, I mean fast. It orbits the entire Sun in just 88 days. The circumference of Mercury’s orbit is 35,983,125 miles (57,909,227 km). It travels at 105,946 mph (170,503 km/h) or 1766 miles (2842 km)/minute or 29.42 miles (47.36 km)/second.
3: Why isn’t Mercury the hottest planet?
Despite being the planet closest to the Sun, Mercury is only the second-hottest planet. Unlike the hottest planet, Venus, with its thick atmosphere, Mercury’s thin atmosphere is less able to trap in the heat. However, it is hot enough to have liquid lead on the surface on the Sun-side, but the night side drops down to as little as 173°C/ 280°F.
4: Is there ice on the planet Mercury?
You wouldn’t expect it on such a hot world, but there are permanently shadowed craters and basins at the North Pole that have plenty of water ice. This was revealed by one of only two probe to visit the planet Mercury. Mariner 10 visited briefly in the mid-1970s, followed by a mission called Messenger which lasted four years until April 30, 2015. Could there be intermediate zones between the permanently frozen or boiled-dry state where liquid water and organics co-exist, and life of some description might flourish? Maybe one day we will find out.
5: How long is a day and year on Mercury?
Mercury’s year is 88 Earth days long, but its day is a whopping 176 Earth days long. That’s twice as long as its year. That’s because Mercury is almost tidally locked to the Sun. We Earthlings only ever see one face of the Moon, because it is completely tidally locked to Earth. The Moon completes one revolution every time the Earth turns once on its axis. Mercury has a few more hundreds of thousands of years before it becomes totally tidally locked.
6: Is Mercury the most cratered planet?
Sitting near the bull’s-eye of a cosmic shooting gallery, Mercury is the most cratered planet in the solar system, with a surface littered with new impact craters found inside older ones.
Unlike other planets whose craters are smoothed away by geological processes, Mercury’s main surface processes have not erased its craters and basins (250km+), which range in size from 100 meters to as big as 1300 km across.
7: What is the planet Mercury made of?
Despite its small size, Mercury still has a molten core which surprised scientists. Such a small planet should have lost its heat and solidified, but Mercury’s core churns on, generating a magnetic field (albeit one hundredth that of Earth) and an actual magnetosphere around the planet to deflect the solar wind. Scientists suspect that the core may be composed of lighter metals or sulfur.
8: Can Hubble look at Mercury?
People wonder if there are any Hubble Space Telescope images of the planet. The fact is that we’ll never get a look at Mercury with the HST because it is too close to the Sun, and the light from the Sun would destroy Hubble’s optics and associated electronics instantly.
9: Can you see Mercury with the naked eye?
Interestingly, you can see the planet Mercury with your own, unaided eyes. All you have to do is know where the sunrise occurs and have a clear view to the horizon. A few minutes before sunrise, Mercury makes its appearance and then vanishes as it is overwhelmed by the light of the rising Sun. At night you can watch the sunset, and after the Sun is gone and the twilight dissipates you can see Mercury as it disappears down below the horizon.
The ancients, before any written history, knew about Mercury. The first written record found mentioned it so casually that it was evident that it was a well-known companion of the Sun for a very long time.
10: What is Mercury’s orbit like?
At closest approach (perihelion) Mercury is only around 29 million miles (47 million km) from the Sun, but at its greatest distance (aphelion) it is 43 million miles (70 million km). Mercury’s highly elliptical, oval-shaped orbit is more eccentric than any of the other solar system planets. In fact, its motion was so peculiar and hard to predict that it actually took Einstein’s general relativity calculations to figure it all out.