Mercury Tectonic Plates

1. Mercury:

The first planet closest to the Sun, Mercury, has a surface geology which is quite rocky, with heavy amounts of craters, boulders, and a lot of pulverized dust. It lacks in atmosphere, due to its moderate day-night variations, particularly in heating by solar energy, and its temperate weather swings as a result of that energy. Temperatures on Mercury range from low (90 Kel.) to high (700 Kel.) though, despite its many observations, it is however quite dead, and it has been for some time.

An interesting feature of Mercury is its magnetic field. As a planet with no cloud activity, no visible signs of existing rivers, dust storms (despite the amount of dust present) and or any other aspects pertaining to weather, this makes Mercury
a rather dull planet in terms of surface geological study. Much of its surface, in fact, bears strong resemblances to the moon, in terms of a visual scope. But...back to the magnetic field. As discovered by Spaceship Mariner 10, Mercury's magnetic field is actually quite small, about 1 of a 100th of the size of Earth's. That it has a field at all is a surprise to Astronomers due to the weakness of its gravitational pull, although it is strong enough to deflect a standard solar wind, and has created a sort of small magnetosphere which surrounds the planet. Of course, newer studies conclude that it is more likely the field originates from within the core of the planet, as opposed to being one with its surface, as with Earth's magnetic field. It is also thought to be more dynamic, as evidenced by its large change during the two observations into the study of its existence beginning in the year 2008. A final notation of interest is that Mercury, on its axis, and like the Moon, has been proven to always be facing the Sun, on one side, and thus its magnetic field (more specifically, the core) is always pointing directly towards the path of the Sun. The pull from the Sun on Mercury's gravitational field, is what is thought to have been the largest modifier for the planet's basic rotation rate since its discovery.

2. Venus:

The largest concentration of chemicals, compounds and elements exists within the atmosphere of Planet Venus. The largest concentration is Carbon Monoxide, at 96.5%, while the final 3.5% is taken up by Nitrogen. Other Periodic elements include Argon, Helium, and Neon. These chemicals, elements, and compounds combine to make Venus's atmospheric pressure up to 90 more times heavier than that of Earth. On its surface level is a thick layer of carbon dioxide, but over this layer is clouds of sulfuric acid, and this reflects 90% of the sunlight which hits Venus. The reflective nature of its clouds presents one aspect, also its closeness to Earth, and thus it is considered one of the brightest objects in our universe.

As to the climate of Venus, it is considered the hottest planet in the solar system, regardless of its proximity to the Sun. Theories suggest it once featured a similar climate to that of Earth, but that greenhouse gases impacted this climate and effectively altered it. Temperatures range on Venus from between -364 to 870 degrees, Fahrenheit.

3.
Earth:

Earth's tectonic plates (or plates which float separately and independently of the hotter mantle which sits below them) are categorized into three major categories, these being: Primary (Major), Secondary (Minor) and Tertiary (or, micro-plates.) The seven major (or, any plates which range over at least 10 million kilometers) plates are: African plate, Antarctic plate, Eurasian plate, Indo-Australian plate, North American plate, Pacific plate and South American plate. These are also the primary plates which formulate the planet's Lithosphere.

The three major categories of plate activity are Divergent, which is where plates move apart from one another, Subduction, wherein an oceanic plate moves beneath a continental plate, and which usually causes the largest amount of volcanic and earthquake activity, and finally, Transform, which is where plates slide back and forth against one another. A result of this activity is that the Earth and its contents were once known as a single continent under the name Pangaea, and which is now comprised of several, separate continents, or areas of land, which continue to move to this day, each time the tectonic plates have
shifted.

4. Mars - Moons: Name, describe, and give a brief history of their names.

The moons of Mars are two in number.
Their names derive from the sons of Ares, who was the Greek and Roman god of War. The Romans would call him Mars. The names of the moons are Phobos, which correlates to Fear, and Deimos, which represents Panic. Their mother was the goddess Aphrodite, the Greek goddess of Love, which is also the name derivation for the planet Venus. In size, these moons are little more than rocks, in their scale, and are thought to be trapped, by the planet's gravitational pull. As discovered by an American Muggle astronomer, Asaph Hall, in 1877, these two moons orbit closely to Mars, and are about only tens of kilometers across in
diameter.

Studies by the orbiters Viking and Mariner, the moons are shown to be irregularly shaped and heavy in their amount of craters. Phobos is the larger of the two, at 28 kilos across, and 20 kilos wide. Its largest crater is a 10 kilo-wide crater by the name of Stickney, named after the aforementioned astronomer's wife, Angelina, while Deimos is 16 kilos long and 10 kilos wide. Deimos's largest crater is only 2.3 kilos in its diameter. Both moons possess dark surfaces, and reflect only about 6% of the light which falls upon them, which contributes heavily to the difficulty astronomers have found in their observations of them.