The Planet Mercury is the closest planet to the Sun. With virtually no atmosphere, the planet has some really harsh conditions with temperatures rising to 840 degrees Fahrenheit during daytime and fall to hundreds of degrees on the negative scale during night. Mercury has almost no atmosphere that can absorb meteor impacts and hence, its surface is strewn with craters.
- Orbit: 88 Earth Days
- Diameter:3,031 miles (4,878 km)
- Day:6 Earth days
The present name given to the planet Mercury is that of the Roman messenger god. This is due to the fact that it circles the sun faster than the other planets. The planet has been named differently by different civilisations. The Sumerians knew about this planet around 5,000 years ago and they associated it with their god writing, Nabu. Mercury is known as a morning star as well as an evening star. However, Greek astronomers knew that both names referred to the same astronomical body.
Mercury is the smallest of all planets. Physically, it is only slightly bigger than Earth’s moon. Due to the absence of a significant atmosphere, the planet faces some of the worst temperatures in the solar system and also is hit by asteroids and meteors. Around 4 billion years ago, Mercury was struck by an asteroid that was roughly 60 miles. The impact was equal to the explosion of a trillion one megaton bombs. The resulting crater is today known as Caloris Basin. It is believed that a similar impact may have resulted in the odd spin that the planet follows presently.
Despite being the closest to the sun, water ice has been discovered in craters around its north pole. Certain regions may be permanently shaded from the sun’s heat aiding in the formation of water ice. The southern orbit has also contained ice, but this has not been validated by scientists yet.
The planet Mercury is the second most dense planet after Earth. It is a core of around 2,200 to 2,400 miles in width. The outer shell of the planet is only 300 – 400 miles thick. This fact is a mystery for scientists till date.
It was recently discovered that the planet Mercury possessed a magnetic field. Due to its slow rotation speed (59 Earth days), the planet was not expected to possess one. The presence of such a magnetic field suggests that its core may still be molten, although solar winds may dampen some of the magnetic field emanating from the planet.