Named for the Roman goddess of love and beauty, the planet Venus has been known since prehistoric times because the planet is one of the brightest objects in the sky. (Only the Sun and the Moon are brighter.)
Although Venus is often called Earth’s sister planet, the two are radically different in very important ways. Despite being close to Earth in size and density, Venus is probably the least hospitable of our solar system’s planets.
The atmosphere is composed mostly of carbon and the several layers of clouds obscuring the planet’s surface are composed of sulphuric acid. Although the winds at the planet’s surface are estimated to be just a few miles per hour, the top layer of clouds are propelled by hurricane-force winds that travel roughly 224 miles per hour.
These clouds are so thick that they make the surface temperature run as hot as 870 degrees Fahrenheit, or hot enough to melt lead. There are more than 1,000 volcanoes or volcanic centers larger than 20 kilometers have been found on the planet’s surface.
Although Venus is nearly twice the distance from the Sun as Mercury, Venus’ surface is hotter. Like Mercury however, Venus has no moons.
Venus take 243 Earth days to rotate once on its axis, but the planet’s orbit around the Sun only takes 225 days, which means a day on Venus lasts longer than a year. Interestingly, the planet also rotates counter-clockwise, which may be because of a collision with an asteroid or other object.
The first spacecraft to visit Venus was Mariner 2 in 1962 and has been visited more than 20 times. Until scientists were able to observe and measure the planet’s temperatures in the 1960s, it was thought that Venus was a tropical paradise.
The Venus Express was launched by the European Space Agency in 2005 and spent 8 years in orbit around the planet. This past summer the spacecraft dipped into Venus’ upper atmosphere; however, the Venus Express is nearing the end of its life as it runs out of fuel. As it falls toward its death, expected to take place December 2014, it will continue to collect and return data on the planet.