Composition of Moon and the Planets in our Solar System

MOON
The Moon's composition is estimated at 45% silica,
plus alumina, lime (calcium oxide), and iron oxide (about 40% in total).
For most practical purposes, the Moon is considered to be surrounded by vacuum.

MARS
Due to its gravity Mars is differentiated, which implies that it has a central core made up of metallic iron and nickel surrounded by a less dense, silicate mantle and crust. Unlike Earth, evidence of molten metal in the Martian core is absent. Hydrogen is present as water (H2O) ice and in hydrated minerals. Carbon occurs as carbon dioxide (CO2 - 95% of the Martian atmosphere) and sometimes as dry ice at the poles. An unknown amount of carbon is also stored in carbonates. Molecular nitrogen (N2) makes up 2.7 percent of the atmosphere. 

Martian meteorite analysis suggests that the planet's mantle is about twice as rich in iron as the Earth's mantle. The planet's distinctive red color is due to iron oxides on its surface. Second, its core is richer in sulphur. Third, the Martian mantle is richer in potassium and phosphorus than Earth's and fourth, the Martian crust contains a higher percentage of volatile elements such as sulphur and chlorine than the Earth's crust does.

MERCURY
The geology of Mercury is the least understood of all the terrestrial planets in the Solar System. This stems largely from Mercury's proximity to the Sun which makes reaching it with spacecraft technically challenging and Earth-based observations difficult. Mercury's density implies a solid iron-rich core that accounts for about 60% of its volume (75% of its radius).

VENUS
Venus's crust appears to be composed of silicate rocks. Venus is presumed to have a core made of semisolid iron and nickel. Its thick atmosphere is made of carbon dioxide and sulphur dioxide.

JUPITER AND SATURN
Spectral analysis of Jupiter and Saturn has revealed that in addition to hydrogen and helium (over 99% of the composition), the planets are made of water, methane and ammonia. Those three elements are in trace amounts.

URANUS AND NEPTUNE
Uranus and Neptune's internal structure is differentiated between a rocky core consisting of silicates and metals; a mantle consisting of water, ammonia and methane ices; and an atmosphere consisting of hydrogen, helium and methane gas.

PLUTO
Pluto is thought to be made of mostly ice. It probably also has a small rocky core which might contain some metals. The ice on the surface of Pluto is made of frozen nitrogen, methane and carbon monoxide.

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