Mercury

The smallest and innermost planet of the Solar system is also least known. Being so close to the sun it is difficult to spot or observe. It is outshined by the light of dawn or dusk. In cities, it is blocked by buildings. Until 2011 we did not have a complete map of the Sun’s first planet. NASA’s Messenger mission started orbiting and started sending stunning views after a gap of 38 years when Mariner 11 was visiting Mercury.

Mercury is only slightly bigger than our own Moon. It resembles the Moon with a surface covered with craters of all sizes, but lakes, dark lava-filled flats, and the mares. Mercury rotates on its axis in 58.65 Earth days, but a day on Mercury lasts 176 Earth days. At the same time, the year of Mercury is 88 earth days long. In other words, by the time a day is over for astronauts in the future Mercurian Colony, planet Mercury will complete two orbits around the Sun. This means that one side of Mercury will remain in sunlight for one Mercurian year of 88 Earth days; while during the next orbit, that side will be in darkness all the time until the next sunrise after another 88 Earth days.

It has almost no atmosphere so surface temperature varies from -170 degrees to 420 degrees. Unlike Earth Mercury has a very little axial tilt of only 2.04 degrees. That’s why it has permanently shadowed polar craters where frozen water ice has been discovered.

A giant iron ball
Its outer rocky crust is only 26 km thick, the rest is a giant iron-nickel core. The most accepted theory is that Mercury’s composition was similar to the most common type of asteroid called chondrite and it was 2.25 times larger than its present size. But during the formative ‘days’ of the solar system like other planets, it has encountered a planetesimal 1/6th of Mercury. That impact stripped most of the crust and what remained was a huge ‘Iron ball’ planet called Mercury. The alternative hypothesis is that the young Sun boiled away most of its outer crust.

Craters are named after creative peoples
Names of features on Mercury come from almost all nations.

Craters are named for artists, musicians, painters and renowned authors. So there is a 200 km wide crater Valmiki who wrote Ramayana. There is a larger 297 km wide crater Vedvyas compiler of Mahabhadra. Anyway, both are bigger than Hemingway which is only 126 km. On the other hand, crater Homer is still larger at 319 km. You can find a crater named Kalidasa 160 km. Shakespeare is the biggest crater at 399 km. Our Rabindranath Tagore and Surdas have also found a proud place on Mercury with 111km and 131 km wide craters.

Ridges and scientists who studied Mercury.
Depressions are named after architects. Montes are named after words for Hot in various languages. Planes for the Name of Mercury in various Languages. Escarpments after scientific ships. Valleys after abandoned cities, towns or settlements from the past.