10 Things You Probably Didn’t Know About Planet Mercury

In around 2012, NASA's MESSENGER spacecraft found water ice in the craters around Mercury's north pole.


Mercury is pretty close to the sun. Moreover, it orbits the sun faster than the rest of the planets of our solar system. Hence, the Romans named it after their messenger god known as Latin Mercurius. Multiple ancient cultures knew of Mercury. It was also linked with Nabu, the god of writing. 

Mercury's Caloris Basin
Mercury’s Caloris Basin. Source: NASA

Timocharis of Alexandria initially discovered Mercury in around 265 B.C. The ancient Greeks assumed that the east and west elongations of Mercury signified two different objects, which they named Hermes, the evening star, and Apollo, the morning star. Greeks, later on, recognized Mercury as a single celestial object and decided to call it Hermes. The people of ancient Egypt, however, discovered that Mercury or Sabkou revolved around the Sun. All in all, ancient civilizations had different opinions about Mercury in general. 

Following are ten facts regarding Mercury. Let’s have a look at them, shall we?

1) Mercury’s weather conditions are unbearable:

Since Mercury is pretty close to the sun, its surface temperature can reach 840 degrees Fahrenheit. However, the planet itself does not have a real environment to capture any heat. Hence, the temperatures generally fall to minus 275 Fahrenheit during the night. 

2) Mercury is quite small:

Mercury is slightly larger than the Earth’s moon. Moreover, it does not have any atmosphere to stop the impacts. Hence, the entire planet is marked with craters. A massive asteroid hit Mercury approximately 4 billion years ago. Its impact was equal to 1 trillion 1-megaton bombs. The collision left an impact crater about 960 miles wide, which is now known as the Caloris Basin

3) Discovery of water ice on Mercury:

As I have stated before, Mercury is pretty close to the sun. In around 2012, NASA‘s MESSENGER spacecraft found water ice in the craters around Mercury’s north pole, where certain areas may be permanently shaded from the sun.

4) Mercury is shrinking with each passing day:

Yes, the small planet is shrinking with each passing day. Mercury is made up of a single continental plate over a cooling iron core. Hence, as the core cools, it hardens, decreasing the planet’s volume and forcing it to shrink further. The said process destroyed the surface of the planet, creating lobe-shaped cliffs, some hundreds of miles long and towering up to a mile high.

5) Mercury is the second densest planet after Earth:

Mercury is known as the second densest planet as it has a massive metallic core about 2,200 to 2,400 miles wide. Moreover, the planet’s exterior is only 300 to 400 miles thick.

6) Mercury possesses a magnetic field:

According to Mariner 10, Mercury has a magnetic field. Planets apparently produce magnetic fields only if they orbit quickly and have a molten core. However, Mercury takes approximately 59 days to pivot and is quite small. According to experts, its core must’ve cooled off ages ago.

7) One year on Mercury is 88 Earth days long:

Mercury revolves around the sun every 88 Earth days. It travels through space at approximately 112,000 mph, faster than any other planet in our solar system. Mercury’s oval-shaped course is highly elliptical, taking it as close as 29 million miles and as far as 43 million miles from the sun.

8) The atmosphere of Mercury:

According to NASA, Mercury has 42% oxygen, 29% sodium, 22% hydrogen, 6% helium, 0.5% potassium, with traces of argon, carbon dioxide, water, nitrogen, xenon, krypton and neon. Moreover, its magnetic field is about 1% the strength of Earth’s.

9) 2 shuttles explored planet Mercury:

The first shuttle to visit the planet is known as Mariner 10, which captured about 45% of the surface and discovered its magnetic field. Moreover, NASA’s MESSENGER orbiter was the second shuttle to visit Mercury.

10) Planet Mercury has wrinkles:

As the iron core of the planet cooled, the surface of the planet became wrinkled. These wrinkles are known as Lobate Scarps.

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