Thursday, July 7, 2011


The planet Venus is the second planet from the sun and is often called Earth's "sister planet" because of their similar size and composition. It is the second brightest object in the night sky, out shined only by the moon. Because of its terrestrial properties, it was thought that Venus might harbor life under its opaque cloud cover. There have been multiple science fiction stories written about it. It has since been discovered, however, that the obscuring cloud layer is composed of sulfuric acid and that the planet is very hot, making it one of, if not the most, inhospitable planets in the solar system.

The atmosphere of Venus is uniquely interesting. Of all of the planets in the solar system, Venus's is the densest. The planets atmosphere also consists mostly of carbon dioxide, meaning that the planet has no carbon cycle or biomass to take the carbon out of the air, yet another sign that the planet is lifeless. It is thought that the planet used to have water oceans, but they evaporated as the planet heated up, and that all of the hydrogen created was whisked away into space by solar winds. Venus has no magnetic field to shield it, meaning that there is nothing to shield its atmosphere from solar winds. The pressure on the surface of the planet is roughly 90 atm, that's 90 times the pressure of earths atmosphere at sea level.

Venus could be an example of the extreme end of the greenhouse effect. With the massive amounts of carbon dioxide in the atmosphere, heat imparted by the sun cannot escape easily, which heats up the surface of the planet significantly, even hotter than the surface of mercury where it faces the sun. The fate of Venus might be an example of what could happen to the Earth if massive amounts of carbon dioxide were to be pumped into the atmosphere.

The surface of Venus has been mapped out by Project Magellan, showing us a bleak landscape shaped by years of volcanic activity. I will provide some links in the comments that show the surface of the planet. One interesting feature of Venus's geography is that its landmasses aren't moving. On earth there is constant plate tectonics which means that our continents are always moving. Venus, however, is still. There are little to no small impact craters of Venus's surface, indicating that most small meteorites burn up in the dense atmosphere, and larger ones break up, making closely clumped impact craters.

Venus reaches its maximum brightness in the early morning and evening, rightfully earning it the title of Morning Star, and Evening Star. Venus has a very slow retrograde orbit. One Venian day is equal to 243 earth days. This slow rotation could be the reason that Venus has no magnetic field.

Our sister planet holds many wonders, but none of which are life. While the planet may have captivated the minds of science fiction writers of the past, it is nothing but dead planet now.

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