From planet of love to scorching Hell planet—the image of Venus has changed considerably since ancient times, because it is no longer just the third brightest natural object in Earth’s skies. The ancients equated the mysterious third light with the goddess of love; in Greece that was Aphrodite, whom the Romans conflated with the goddess Venus. That’s where our closest planetary neighbor got its name and why Men are from Mars, Women are from Venus worked as a best-selling title, as recently as 1992, and still sells. But since the mid-20th century, we’ve known in detail why a paradise Venus is not. Average temperature on the surface is a scorching 462° Celsius (864° Fahrenheit) while atmospheric pressure is 90 times that of Earth at sea level, or equivalent to being at 900 meters depth in Earth’s oceans.
A handful of Russian landing probes have survived for several minutes on the planet’s surface before being cooked and crushed, but the conditions are unquestionably inhospitable for life forms. Consequently, you do not hear about astrobiologists searching for native microorganisms on the Venusian surface the way you hear about the search for microorganisms on Mars. Nevertheless, since the late 20th century, planetary scientists have speculated that Venus could have boasted a much more hospitable environment in the distant past, perhaps 2–3 billion years ago. That’s around the time that Earth was accumulating oxygen in its oceans and atmosphere. At that point in history, Venus and Earth may have had similar climates.
What’s been in the news lately is a study involving computer climate simulations in which data from NASA’s Magellan mission to Venus were found to support the idea of a once habitable Venus. The study involved researchers from NASA, Uppsala University in Sweden, Columbia University, and the Planetary Science Institute in Tucson, AZ.