Реферат: Planets And Solar System Essay Research Paper

wrinkles that might form in the crust if the interior of the

planet shrank slightly ” (Morrison, 74, 1993). It is speculated

that it was the solidification of Mercury’s metallic core that

caused this global shrinkage. Mercury is also ” . . . enriched

in metal or depleted of rock ” (Morrison, 74, 1993). It is also

believed that some of the inner core of Mercury is still in a

fluid state.

Scientists also believe that Mercury’s surface is made partially

of silicate rock. The best way to describe Mercury is, ” . . .

small, heavily cratered and airless ” (Morrison, 71, 1993).

Venus is the second closest planet to the sun and is said to

” . . . most closely resemble Earth in size, density, and

distance from the sun ” (Thompson/Turk, 542, 1993). Venus is

known to most scientists as the sister planet to the Earth. It

is called this because it closely resembles the Earth’s mass,

density and diameter. The only thing different is that Venus ”

is shrouded in thick clouds that completely hide the surface of

the planet ” (Grolier, 1992). The surface temperature is also

much warmer than that of Earth.

Venus completes one revolution around the sun in 224.7 days.

This makes the Venusian day equal to 117 earth days. It is

thought that this slow rotation may be the reason why Venus has

no magnetic field.

Planets 4

The atmosphere of Venus made up of 98% carbon dioxide and

2% Nitrogen. This atmosphere also has the presence of helium,

neon and argon. This is yet another thing which makes Venus

different from Earth.

The surface of Venus is quite a bit like that of the Earth.