Planet number four in the solar system is the Planet Mars. Mars is a cold and dusty place with the nickname “The Red Planet” due to the presence of iron oxide in the dust. The Martian territory is similar to the terrain of Earth with valleys and mountains. Mars receives some snowfall and has water in the form of ice. Due to all this, scientists believe that the planet must have been warm and wet once before it became the cold and desert-like planet it is today.
- Orbit: 687 days on Earth
- Diameter: 4,217 miles (6,787 km)
- Day: Slightly more than one Earth day (6,787 km)
The planet Mars is named after the Roman god of war. In actuality, Romans copied from the Greeks who had named it as Ares, due to its colour. Other civilisations that have seen mars have also given it colours based on its colour, namely Her Desher (The Red One) by the Egyptians and The Fire Star by the Chinese.
This planet contains both deepest valley and the highest mountain in the solar system. The Valles Marineris valley system is as deep as 6 miles and has a width of around 2,500 miles, while the Olympus Mons have a height of 17 miles.
The Martian atmosphere is too thin making it impossible for liquid water to exist for any length of time. However, there is a belief that the planet may have supported life previously and scientists continue to search for any signs of life in the past.
Mars has the largest volcanoes and they are shield volcanoes. They were created by the flowing of erupted lava for long distances before it solidified. The planet Mars has other volcanic landforms such as small steep cones and plain’s that are coated in hardened lava. Some minor volcanic eruptions might still occur on the planet even today.
The Planet Mars has numerous valleys, gullies and channels giving rises to the suggestion that liquid water may have existed on the planet sometime in the past. Some of these channels are 60 miles wide and around 1200 miles long. Water may still be found in some underground rocks and cracks.
The Martian landscape also contains numerous craters and theses vary based on how old that particular surface is. The southern hemisphere is extremely old with many craters, while the northern hemisphere is relatively new and has fewer craters. Sometimes lava erupting from volcanic eruptions cover up the old craters and thus, alter the landform.
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.