Planet Venus, second from the Sun Sister World or Evil Twin?
Venus is nearly the Earth's twin in terms of size, density, and mass. Venus'
diameter is 7,521 miles at the Equator, and Earths' is 7,926 miles at the
Equator. The very slow rotation speed of Venus gives it a nearly perfect
sphere shape, where most planets have some flattening at the poles and bulging
at the equator due to their faster rotation speeds. The orbit of Venus is the
closest to being a perfect circle out of all the Planets in the Solar System.
I have listed the data from my, "Planets Article", here for you to review:
Distance from Sun (mean): 67.0 million miles or 0.72 AU
Closest approach to Earth: 25.7 million miles
Length of year (in Earth time): 224.7 days
Average orbital speed: 78,341 miles per hour
Rotation period (in Earth time): -243 days (retrograde)
Diameter at equator: 7,521 miles
Number of known moons: 0
The (retrograde) you see by the Venus "Rotation period" of -243 days means
that Venus Rotates clockwise on its axis forming night and day. Earth and
most of the other Planets Rotate counter clockwise forming night and day
with the Sun rising in the East and setting in the West. Planet Uranus
and Planet Pluto also have (retrograde) Rotation like Planet Venus does.
Venus Rotates on its axis so VERY slowly that one day on Venus is as long
as 243 days on Earth! So on Planet Venus one Day is longer than one Year!
All of the Planets orbit the Sun in a Counter Clockwise direction.
Distance from Sun (mean): 93.0 million miles or 1.00 AU
Length of year (in Earth time): 365.25 days
Average orbital speed: 66,629 miles per hour
Rotation period (in Earth time): 23 hr 56 minutes
Diameter at equator: 7,926 miles
Number of known moons: 1
From the "Planets Article" data above you realize that Planet Venus is rotating
on its axis VERY slowly, and that it is rotating in a clockwise (retrograde)
motion. The Earth rotates counter clockwise which has the Sun rising in the
East and setting in the West. Standing on Planet Venus, (if the dense clouds
were parted), you would see the Sun Rise in the West and set in the East 121
Earth Days later! Wow what a long day that was! The daylight period on Venus
lasts for 121.5 Earth days, and the night time period lasts for 121.5 Earth
days because Venus takes 243 Earth days to rotate once on its axis. The Earth
rotates on its axis (forming night and day) at a speed at the equator of about
1,037 miles per hour. Venus rotates on its axis at a speed at the equator of
about 4 miles per hour! If you put on your best "Speed Walk" you could walk at
the speed of 4 miles per hour. Now you have an example of just how slowly
Planet Venus is rotating on its axis! Being closer to the Sun, Venus orbits the
Sun in only 224.7 Earth Days forming one Venusian Year. The Earth orbits the
Sun in 365.25 days as you know which gives us an extra day in February every 4
Venus surface temperature is 900 degrees F and yet the atmosphere reflects 80%
of the Sunlight back to space, while trapping the heat rays from the Sun,
making Venus one of the Brightest Planets in the sky, and one of the hottest.
The large amount of carbon dioxide gas in the Venusian Atmosphere is trapping
the Sun's Heat energy and causing the: "run away greenhouse effect" where the
atmosphere gets hotter and hotter. This is the same effect as the very slow
global warming we are worried about here on Earth. The massive atmosphere and
very thick clouds are all that can been seen by telescopes here on Earth or by
orbiting spacecraft. America was able to map the surface of Venus using its
Magellan Spacecraft that arrived in orbit on August 10th 1990. Magellan was
the first planetary spacecraft launched from the Space Shuttle. The spacecraft
was named after Ferdinand Magellan, the sixteenth-century Portuguese explorer
whose expedition first circumnavigated the Earth. The Magellan orbiter made
detailed maps of 98 percent of the planet's surface using synthetic aperture
radar. The Radar Imagery showed volcanos had effected about 85% of the surface
of Venus and the rest had ranges of deformed mountains. Maxwell Mons is the
highest mountain on Venus at 35,000 feet, which is 7,000 feet higher than Mount
Everest here on Earth! Scientists think there may be up to a hundred thousand
volcanos on Planet Venus compared to some 15 hundred here on Earth. They think
Basalt Lava Rock makes up 70% of the Surface of Venus.
This global view of the surface of Venus is centered at 0 degrees east
longitude. Magellan synthetic aperture radar mosaics from the first cycle
of Magellan mapping are mapped onto a computer-simulated globe to create
this image. Data gaps are filled with Pioneer-Venus Orbiter data, or a
constant mid-range value. Simulated color is used to enhance small-scale
structure. The simulated hues are based on color images recorded by the
Soviet Venera 13 and 14 spacecraft. The image was produced by the Solar
System Visualization project and the Magellan Science team at the JPL
Multimission Image Processing Laboratory, and is a single frame from a
video released at the October 29, 1991, JPL news conference.
Venus has the most massive atmosphere of all the inner planets. Its atmosphere
is composed of 96.5 percent carbon dioxide (CO2) and 3.5 percent nitrogen (N2).
Trace amounts of a number of other gases have been detected, including carbon
monoxide (CO), sulfur dioxide (SO2), water vapor (H2O), argon (Ar), and helium
(He). The atmospheric pressure on the surface of Venus is 90 times more than
the atmospheric pressure on Earth. The same pressure can be found on Earth at
about 3,000 feet deep in the Ocean! The atmospheric pressure at the surface of
the Earth is about 14.7 pounds per square inch, on every inch of your body. We
are from Earth so our bones and muscles are designed to withstand this pressure
and the effects of the Earth's Gravity. The atmospheric pressure on your body
on the surface of planet Venus would be 1,323 pounds per square inch! Your body
would be reduced to a pulp about a quarter inch thick! HA HA Ha! Flat as a Pan
Cake as we say here in America. The first few spacecraft sent to Venus by
America and the Soviet Union were crushed by the atmospheric pressure or had
their electronics fried by the 900 degree F heat at the surface. If we put on
our specially designed space suits and walked out onto the surface of Venus we
would find the dim sunlight filtering thru the clouds far less than we are used
to on Earth during the day time. The yellowish tinge to the air around us from
all the sulfur from volcanic activity really adds an alien look to the terrain.
Our vision would also be distorted by waves of heat rising from the surface.
Any hot summer day on Earth just go look down the railroad tracks to glimpse a
similar heat distortion or shimmer due to the heat rising from the vegetation
free, rocky railroad track bed.
The clouds that enshroud Venus are enormously thick. The main cloud deck
extends from about 45 km (28 miles) above the surface up to nearly 70 km (43
miles). The microscopic particles that make up the Venusian Clouds consist of
liquid droplets and perhaps also solid crystals. The dominant material that
has been identified in the clouds is highly concentrated sulfuric acid, H2SO4.
Other materials that may exist include solid sulfur and nitrosylsulfuric acid
The circulation of the Venusian atmosphere is quite remarkable and is unique
among the planets. Even with the Very slow rotation speed of Planet Venus the
high cloud tops circle Venus in only about 4 days! These high clouds are moving
at 360 km per hour (224 miles per hour) from east to west. I would not expect
such fast winds on a Very slowly rotating planet. These fast westward high
level winds decrease in speed as you approach the surface. Surface wind speed
is very slow around 4 kilometers per hour (2.5 miles per hour). The cause of
the fast upper level winds on Venus is not well understood and remains a focus
of scientific controversy and research.
Unlike most planets, Venus does not have its own intrinsic magnetic field.
Sensitive measurements by orbital spacecraft have shown that any field
originating from within Venus is far weaker than the Earth's magnetic field.
The lack of a magnetic field may be related to the very slow rotation of Venus
since the current dynamo theory of the generation of planetary magnetic fields,
says rotation speed helps to drive the motions within the planet's interior
that produce the field.
From my article "The Birth and Death of Our Sun" you learned just how important
a strong magnetic field is to life here on Earth! You learned the Sun gives off
a constant stream of charged particles, mostly protons and electrons, we call
the "Solar Wind." When comets come into the inner solar system their long
gaseous tails always point away from the Sun because of the Solar Wind blowing
them back! Earth's magnetic field deflects the Solar Wind around the planet
long before it gets close to interacting with our precious atmosphere! Planet
Venus has no protective magnetic field so the Solar Wind hits the top of the
planet's atmosphere directly. That point is heated up and compressed by the
force of the Solar Wind striking it, but the Solar Wind is still deflected
around the planet. The force of the Solar Wind pushes the atmosphere closer to
Venus on the Sunward side, and of course the side away from the Sun bulges out
further from the surface of Venus. The Solar Wind is eroding the Venusian
atmosphere but Venus has the most massive atmosphere of all the inner planets
as we said earlier. The portion of the solar wind that does not interact with
the Earth or the other planets continues to travel to a distance of
approximately 20 astronomical units, at which point it cools and eventually
diffuses into galactic space.
The surface of Venus is very different from any other planet in the solar
system with its high atmospheric pressure, low wind velocities, and the
extremely high temperatures at the surface. The Soviet Union made a series of
landings in the 1970s and early 1980s that gave us detailed data on the
appearance and make up of the surface of Planet Venus. Spacecraft Venera 13
took a nice panorama view of the surface which shows the flat, slabby, layered
nature of the rocks. Volcanic and sedimentary rocks on the Earth can develop
such an appearance, but the reason that the Venusian rocks exhibit these
physical characteristics is not known. Some darker fine-grained soil was
present and lifted into the air by the touchdown of Venera 13. Small pebble
sized rocks or clods of soil were also scattered about the landing site. Even
with the heavy cloud cover there is enough light filtering through the clouds
for the picture. The yellowish tint to the air really adds an alien look to
the whole scene. Use the Link provided below to view this excellent picture
of the surface of Planet Venus! You see part of the spacecraft at the bottom of
I have provided you links below to the Magellan Spacecraft site and to the
Venus Express Spacecraft site. Venus Express is in orbit around Venus NOW and
is sponsored by the European Space Agency.
May the FORCE be with you! Live Long and Prosper! May HE whom the winds fear
Light your Path and Guide your Steps as you journey through this life.
Written by:The Galactic Sage