Tour of the Solar System: The Planet Venus

Next up on our Tour of the Solar System is the second planet from the Sun, the planet Venus. Venus is located about 108 million kilometers from the Sun, about three quarters of the distance between the Earth and Sun. 

Like Mercury, Venus is always hanging somewhere near the Sun when you look at our sky.  It is only visible from the earth during the evening just after sunset, or shortly before sunrise in the early morning.  Venus is often mistaken as a UFO since it wanders around the sky each night, and it is also the brightest object in the evening sky.  During the evening hours, it usually the first object seen, before all of the other stars peek out from the black veil, in the western sky just above the horizon.

Venus is a perfect example of what happens when the 'greenhouse effect' goes awry. Its atmosphere is largely made up of carbon dioxide.  Since the mid to late 1800's, it has been hypothesized by scientists here on Earth that high amounts of carbon dioxide in an atmosphere will help to trap tremendous amounts of heat.  The Venusian atmosphere is dense, more than 90 times the density of our own atmosphere.  Thus, it keeps a huge amount of heat it receives from the Sun trapped within its atmosphere.

Due to the extreme pressures of the Venusian atmosphere, it would seem unlikely that we would ever be able land humans on the planet's surface. It was a popular legend when I was growing up that the Soviets also sent cosmonauts on suicide missions to Venus. I doubt that one is true.  However, the former Soviet Union did manage to land probes on Venus in the '70's and 80's that were able to send back images and bits of data. The probes survived from just  a few minutes to a couple hours before they were rendered inoperable by the extreme temperatures and high pressures of the atmosphere.  The surface temperature of Venus approaches 800 F which is twice as hot as one most of our baking ovens here on Earth. The images that were returned  truly depicted a hellish environment.

Not only does Venus have an inhospitable atmosphere, but the surface of the planet may be hard looking place.  Radar mapping of the planet has revealed plenty of volcanic eruptions.  And since there is evidence of sulfuric acid raining down, some of these eruptions may be recent or are still ongoing.  Radar maps have also revealed that the Venusian landscape is made up of several continents. There is one mountain that stands 11 KM high.

Venus has many remarkable similarities to our own planet.  It is about the same size, has similar gravitational effects, and is made up of many of the same materials.  However, Venus has one distinct difference about itself that makes it stand apart from all other planets in our solar system, including the Earth.  The difference is that Venus rotates in a completely opposite direction on its axis, clockwise, as view from above the elliptic plane. It also has a very slow rotation taking 243 earth days to complete a Venusian day.  The planet has a unique property in that its day last longer than its year!