Astronomy for Curious Minds: Interesting Facts about Mercury

Mercury is the classical and smallest planet in the solar system, named after the Roman messenger god.

It is visible with the naked eye from Earth’s surface.

If you are wondering who discovered the planet mercury, then the answer is- it is not known yet! Since ancient times, people of various cultures have observed Mercury (planet), and the earliest record of it comes from Sumerians (3000 BC).

In the seventeenth century, astronomers Galileo Galilei and Thomas Harriot observed this planet through telescopes.

Description of Mercury

The characteristics of Mercury include various parameters like density, orbit time, etc.

Mercury’s size is 2,439.7 kilometers in radius with a mass of 3.285 × 10^23 kg.

Mercury volume is 60.8 billion cubic km.

To know more about Mercury's unique features, read this article until the end.

How long is a day on Mercury?

It is the closest planet to the Sun and is tidally locked to it.

Distance from the Sun to Mercury in km is 58 million.

Hence, its rotation is slowed down, and it nearly matches its orbit around the Sun.

When compared to Earth, the planet Mercury rotates slowly.

Hence, a day on Mercury is very long and is 58.646 Earth days, while one solar day on this planet is 176 Earth days.

Crazy Orbit of Mercury

The planet Mercury moves faster around the Sun as compared to other planets.

Mercury orbit time is 47km/s.

It has the highest orbital eccentricity and travels 180,000 km/h along its elliptical orbit.

It gets as close as 47 million km and as distant as 70 million km from the Sun.

So, a year on the planet Mercury is 88 days long.

Is Mercury the densest planet?

Although Mercury is the smallest, it is very dense.

It is the second dense planet in the solar system.

One cubic centimeter of Mercury has 5.4 grams of density.

This is because of its composition consisting of rock and heavy metals.

Mercury and its Wrinkles

Yes, Mercury has wrinkles.

It is one of the interesting facts about Mercury.

The iron core of Mercury is cooled and contracted, which gives its surface a wrinkled appearance.

The wrinkles are named ‘Lobate Scarps', which extend up to hundreds of miles in length and a mile high.

Do you know about Mercury’s impact on Giant Asteroid?

About 4 billion years ago, Mercury's planet experienced an impact from a huge asteroid around 100 km wide.

This impact created a giant crater, Caloris Basin, about 1,545 km.

Does Mercury have water?

There is ice in the south and north poles of Mercury's craters.

The poles are shadowy and cold, which allows them to retain water/ice.

Scientists believe that comets and meteorites have delivered ice to that area.

They also believe that water vapour from the planet may have seeped out and frozen. 

Mercury’s Core has iron in it.

Mercury planet has a metallic iron core that is partly molten.

It makes up about 3/4 of its mass and takes up around 75 per cent of its radius.  

The remaining surface is a rocky silicate shell. Hence, Mercury is a type of terrestrial planet (with a solid surface).

Does Mercury have an atmosphere?

As per NASA scientists, Mercury has an exosphere.

The planet’s atmosphere is very thin and does little to slow down or prevent impacts from extraterrestrial objects.

This explains the craters on the surface of this planet.

Solar wind and micrometeoroid impact blast off atoms.

These atoms are responsible for the creation of their atmosphere.

Mercury's atmosphere composition includes hydrogen, oxygen, helium, sodium, and potassium.

'Tails' of Mercury

Scientists believe that the Sun's wind and Mercury's magnetosphere are responsible for the tail shapes.

These tails are streams of particles casting off the planet's surface.

Does Mercury have any moons?

This planet is one of the two planets in our solar system without any moons.

This is because of the small size of Mercury, which further attributes to its weak gravity.

Also, its distance from the Sun is another factor as the strong gravitational pull of the Sun can pull them out of Mercury's orbit.

Does Mercury have rings?

No. There are no rings around the planet Mercury.

NASA’s Mercury Mission

During 1974 and 1975, Mariner 10 mapped under half of Mercury's surface.

In March 2011, NASA carried out a mission.

Its MESSENGER is the first probe to orbit the planet Mercury.

During this mission, Mercury's structure of its Core, composition, and magnetic field was determined, and images of the surface in different wavelengths were taken.

The two spacecraft of BepiColombo are enroute to this planet.

There are many other cool facts about Mercury.

This article offers information on Mercury to help the readers know a little more about the special features of Mercury