Essay About Large Meteoroids And Earth Days

Venus
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Venus is the second planet from the sun and the sixth largest. Venus
orbit is the most circular of any planet, with an eccentricy of less than 1%.
Venus, perhaps because it is the brightest of planets known to the ancients,
Is named after the Greek goddess of love and beauty. The planet of Venus
has been known since prehistoric times and is the brightest object in the
sky with the exception of the sun and the moon.
Venus rotation is somewhat unusual in that it is both very slow ( 243
Earth days per Venus day) and retrograde. In addition, the periods of
Venus rotation and of its orbit are synchronized such that it always
presents the same face toward Earth when the two planets are at their
closest approach. The pressure of the planets atmosphere at the surface is
90 atmospheres and is composed mostly of carbon dioxide. There are
several layers of clouds which are many kilometers thick and composed of
sulfuric acid. This dense atmosphere produces a run-away greenhouse
effect that raises Venus surface temperature by about 400 degrees to over
740 K.
The planet of Venus is often regarded as Earths sister planet, in
some ways they are very similar. For example, Venus is only slightly
smaller than Earth (95% of Earths diameter, 80% of Earths mass.) Both
have few craters indicating relatively young surfaces. Their densities and
chemical compositions are also similar. Because of these similarities, it
was once thought that below its dense clouds, Venus might be very
earthlike, perhaps to the point of containing life. However, a more detailed
study of Venus revealed that many aspects of Venus atmosphere was much
different from that of Earth.
There are no small craters on Venus. It appears that small
meteoroids burn up in Venus dense atmosphere before reaching the
surface. Craters on Venus seem to come in bunches indicating that the
large meteoroids that do reach the surface usually break up in the
atmosphere. The oldest terrains on Venus seem to be about 800 million
years old. Extensive volcanisms at the time wiped out the earlier surface
including any large craters from early Venus history.
The interior of Venus is probably very similar to that of Earth. It
consists of an iron core about 3000 km in radius, a molten rocky mantle
comprising the majority of the planet. Venus probably once had large
amounts of water like Earth but it all boiled away, leaving Venus quite dry.
If Earth had been just a little closer to the sun, it would have had a
similar
fate.