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. .
The surface has volcanoes and smooth plains. " Much of the .
volcanic activity on Venus takes the form of Basaltic eruptions .
that inundate large ares, much as the mare volcanism flooded the .
impacted basins on the near side of the moon " (Morrison, 93, .
1993). One thing that differs from Earth is that there is no .
water liquid on the Venusian surface. .
Some of the scientific data that follows was taken out of .
Cattermole's book. The mean distance from the sun is 108.20 Km. .
The equatorial diameter is 12,012 Km and the equatorial rotation .
is 243 days. Finally the mass of Venus is 4.87*10^24 .
(Cattermole, 63, 1993). Venus, although different than Earth, is .
still our sister planet.
