VENUS Research
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The surface of Venus is a very hot and dry place. Most of
the surface is made up of gently rolling plains. Venus has several large
lowlands and two large highland areas which are about the size of Australia and
South America. Venus has several mountains and volcanoes and much of its
surface is covered with old lava flows. The highest mountain on Venus is
Maxwell Montes. It is more than 7 miles high and is higher than Mt. Everest.
Venus does not have many craters because most meteors burn up in its thick atmosphere,
and many of the meteor craters which did exist have been covered by lava flows.
The atmosphere of Venus is too thick for us to see its surface, however, radar
can pass through the thick atmosphere of Venus, allowing us to find out what
the surface is like.
Overview of Surface
The surface of Venus is rather
smooth in many places, though not nearly as smooth as originally expected .
However, we find evidence for many of the same geological features found on
Earth: canyons, volcanoes, lava flows, rift valleys, mountains, craters, and
plains. There is substantial evidence for local tectonic activity but the
surface appears to be a single crustal plate, with little evidence for
large-scale horizontal motion of crustal plates as found on the Earth. Why the
two planets differ in this aspect of their geology even though we believe them
to have similar interiors is not well understood. The usual explanation is that
Venus is a little behind the Earth in geological timescale, and its tectonic
activity is just getting started.
Much of the surface of Venus
appears to be rather young. The global data set from radar imaging reveals a
number of craters consistent with an average Venus surface age of 300 million
to 500 million years.
There are two
"continents", which are large regions several kilometers above the
average elevation. These are called Istar Terra and Aphrodite Terra.
They can be seen in the preceding animation as the large green, yellow, and red
regions indicating higher elevation near the equator (Aphrodite Terra) and near
the top (Ishtar Terra).
Examples of Surface Features
We now survey a few of the prominent types of surface features that have
been discovered on Venus.
Mountains
Venus has high mountains, many of which appear to be volcanic in origin.
The bright region near the center in the polar hemispheric view (a) above is
Maxwell Montes,the highest mountain range on Venus; it reaches an elevation of
11 km above average elevation (2 km more than the elevation of Mount Everest
above sea level on Earth).
Volcanos and Lava Flows
There is strong evidence that volcanoes
have erupted on Venus in the geologically recent past, and strong indirect
evidence from observations like changing chemical composition of the atmosphere
and the detection of lightning in certain regions that volcanoes are presently
active on Venus, though we do not yet have direct proof. (Here is a map
of volcanic structures on Venus.) One piece of evidence for recent volcanic
activity is the presence in many regions of features that look like relatively
new lava flows. The two images shown below illustrates a volcano about 3 miles
in diameter near Paragon Chasma (left) and an image of apparent recent lava
flows in the Sif Mons region.
In all of these radar images you should bear in mind that bright spots
correspond to regions that reflect more radar waves than other regions. Thus,
if you could actually see these regions with your eyes the patterns of
brightness and darkness would probably not be the same as in these images.
However, the basic features would still be the same.
Rift Valleys
There are rift valleys as large as the East African
Rift (the largest on Earth). The image shown below illustrates a rift
valley in the West Eistla Region, near Gula Mons and Sif Mons.The perspective in cases like this is synthesized
from radar data taken from different positions in orbit.
The East African Rift on Earth is a consequence of
tectonic motion between the African and Eurasian plates (the Dead Sea in Israel
is also a consequence of this same plate motion). Large rift valleys on Venus
appear to be a consequence of more local tectonic activity, since the surface
of Venus still appears to be a single plate.
Meteor Craters
The
surface of Venus has been smoothed by recent lava flows and by interaction with
the corrosive atmosphere. However, there are various examples of meteor
craters. The following images show a field of craters (left) and the largest
crater found (right).
Several
lines of evidence point to ongoing volcanic activity
on Venus. During the Soviet Venera program, the Venera 11
and Venera
12 probes detected a constant stream of lightning,
and Venera 12 recorded a powerful clap of thunder soon
after it landed. The European Space Agency's Venus
Express recorded abundant lightning in the high atmosphere. While rainfall drives thunderstorms on Earth, there is no rainfall on the
surface of Venus (though sulfuric acid rain falls in the upper atmosphere,
then evaporates around 25 km above the surface). One possibility is that
ash from a volcanic eruption was generating the lightning. Another piece of
evidence comes from measurements of sulfur
dioxide concentrations in the atmosphere, which dropped by a factor of 10
between 1978 and 1986. This may imply the levels had earlier been boosted by a
large volcanic eruption.
Wiki
and Drifting on Alien Winds
CULTURE
Venus
is the only planet with a female name.
The astronomical symbol is the same symbol used in biology for the
female sex; a circle with a cross below it. Greeks named the planet after Aphrodite,
goddess of beauty, love, grace and sexual exhilaration.
Mayan
civilization created their calendar based on the movements of Venus. Venus is
also known as the morning star or twilight star, since it’s the brightest at
dawn and dusk. The Pawnee, a North American native tribe, until as late as
1838, practiced a morning star ritual in which a girl was sacrificed to the
morning star
Venus
is important in many Australian aboriginal cultures, such as that of the Yolngu
people in Northern Australia. The Yolngu gather after sunset to await the
rising of Venus, which they call Barnumbirr. As she approaches, in the
early hours before dawn, she draws behind her a rope of light attached to the
Earth, and along this rope, with the aid of a richly decorated "Morning
Star Pole", the people are able to communicate with their dead loved ones,
showing that they still love and remember them. Barnumbirr is also an important
creator-spirit in the Dreaming, and "sang" much of the country into
life.
Landis, Geoffrey A. (2003). "Colonization of
Venus". AIP Conference Proceedings 654 (1).
pp. 1193–1198. doi:10.1063/1.1541418.
Colonization
Owing
to its extremely hostile conditions, a surface colony on Venus is out of the
question with current technology. The atmospheric pressure and temperature
approximately fifty kilometres above the surface are similar to those at the
Earth's surface and Earth air (nitrogen and oxygen) would be a lifting gas in
the Venusian atmosphere of mostly carbon dioxide. This has led to proposals for
"floating cities" in the Venusian atmosphere. Aerostats
(lighter-than-air balloons) could be used for initial exploration and
ultimately for permanent settlements. Among the many engineering challenges are
the dangerous amounts of sulfuric acid at these heights
Drifting on Alien Winds by Michael Carroll
Average surface temperatures reach a searing 864F.
At night, the rocks are so hot that the landscape glows a dull red. Planet is
dry. Sulfuric acid rains from an eternally overcast and gloomy sky the rain
never reaches the surface, it evaporates before it could. Earth’s twin sister, and
is the closest planet to us. Venus has volcanoes that are powered by the planet’s
internal heat. Venus’s atmosphere is blanketing by a dense canopy of almost
pure carbon dioxide that traps heat from the sun in self-reinforcing greenhouse
cycle.
The atmosphere is covered in the thick layers sof clouds.
The base of the lowest cloud deck is 30 miles above the surface, the air is
clear. The clear air pours sulfuric acid rain that never makes the ground. High
temperatures and updrafts assure the rainfall on Venus becomes virga, rain that
evaporates before it makes landfall.
Rather than familiar billowing walls of opaque
white, the clouds of Venus are more like thin fog or haze stretching from one
horizon to the other. We can’t see surface of Venus from the outside is not because
clouds are dense, but because there is so much of them. Winds carry clouds
around the globe every 4 days known as “superrotation”. Winds are at 100km/h
where is pressure is 16 times more than the surface of the Earth.
In 1995 bizarre readings made it look like it was
snowing metal. The radar had bright reflections, and dude to Venus’s drastic
pressures specific metals may exists as a vapor. A haze of metallic vapor. Theorized a hardware issue but three other
probes experienced similar power spikes at the same altitude.
