October 02, 2012, 10:09 AM — You'd think after a few billion years of living next to each other, you'd know everything about your neighbors.
But in recent days scientists have reported some unexpected and counterintuitive findings about Venus and Mars, the planets on either side of Earth in our solar system. Maybe not as unexpected as learning that the prim accountant next door is a cross-dresser, but still.
According to the European Space Agency, Venus -- the second-closest planet to the Sun (after Mercury) but the hottest, with a mean surface temperature of 863ºF -- contains a "surprisingly cold region high in the planet’s atmosphere that may be frigid enough for carbon dioxide to freeze out as ice or snow."
How cold? Try –175ºC, or -283ºF. To give you some perspective, the coldest recorded temperature on Earth was −128.6ºF in Antarctica in 1983. Break out the shorts and tank tops!
Results of the data analysis will be published in the Journal of Geophysical Research.
On to Mars, which has a mean temperature of –63ºC, or -81ºF, and goes as low as –143ºC, or -225ºF.
NASA's Mars Rover Curiosity, equipped with weather data instrumentation, has detected afternoon temperatures as high as 6ºC, or 43ºF. NASA's Mars Science Laboratory scientists say temperatures have risen above freezing for more than half of the days since Curiosity has been monitoring environmental conditions in Gale Crater just south of the Martian equator.
What's especially interesting about this is that it's late winter where Curiosity has been roaming since landing on Mars on Aug. 5. One would assume temperatures will climb higher during daytime in the spring and summer.
It's a different story at night, however, thanks to the thin Martian atmosphere and its inability to retain heat. Curiosity has measured nighttime temperatures as low as -70ºC, or -94ºF. So if you're going out, bring a sweater.