What did you learn about Venus - sometimes
called our sister planet - when you were in school? Unless you are still in
school, chances are that at least some of those ‘facts’ have changed.
Venus has been called Earth’s twin,
because it is similar to Earth in size and mass. Venus’ diameter is 7,520.8
miles, only 396.7 miles smaller than Earth’s. Its mass is 81.5 % of Earth’s.
But in other ways, they are not very alike at all.
Venus is still the second planet
from the Sun, it is still named after the Roman goddess of love and beauty. It
orbits the sun in 224.7 Earth days. A Venus day is 243 Earth days, so its day
is longer than its year. It also rotates in the opposite direction as Earth, so
on Venus, the sun rises in the west and sets in the east. It still does not
have any moons.
Venus has the densest atmosphere of
the 4 inner planets, which consists of more than 96% carbon dioxide. At Venus’
surface, the atmospheric pressure is 92 times that of Earth, or roughly the
pressure found at 3,000 ft underwater on Earth.
Venus is the hottest planet in the
solar system, with a mean surface temperature of 863°F. Mercury is closer to
the sun, but Venus is hotter. It is shrouded by an opaque layer of clouds of
sulfuric acid. It may have had water oceans at some point in the past, but they
would have vaporized due to a runaway greenhouse effect. That water vapor would
have photodissociated, and the resulting free hydrogen swept into
interplanetary space by the solar wind because Venus doesn’t have a planetary
magnetic field. It is postulated that the surface of Venus is a desertscape
interspersed with slab-like rocks and is periodically resurfaced by volcanism.
In my youth, I remember reading
books and short stories that postulated that Venus weather included perpetual
rain, and that Venus was a water planet. In both cases, humans from Earth had
colonized Venus. But given the updated information on Venus’ atmosphere and
surface, colonization may have to wait until some type of reclamation can happen.
Perhaps remove some (a lot!) of carbon from the atmosphere, and set up some
type of artificial field around the planet to keep the solar wind from removing
any more of the lighter elements from that atmosphere. If we can lessen the
green-house effect, then maybe the volcanism will also settle down a bit.
No comments:
Post a Comment