A number of agencies, including, of course, NASA, are focusing solar system exploration efforts on Mars. At first glance, though, Mars doesn’t really seem like the best candidate. Venus is much closer — at a distance that ranges between 38 million kilometres and 261 million kilometres, compared to Mars’ 56 million to 401 million kilometres, it’s Earth’s closest neighbour.
It’s also comparable in size to Earth — a radius of 6,052km to Earth’s 6,371 — and has similar density and chemical composition.
But everything else about it makes it almost utterly unvisitable. While probes have been sent to the planet’s surface, they lasted, at most, just two hours before surface conditions on Venus destroyed them. These conditions include an atmospheric pressure up to 92 times greater than Earth’s; a mean temperature of 462 degrees Celsius (863 degrees Fahrenheit); extreme volcanic activity; an extremely dense atmosphere consisting mostly of carbon dioxide, with a small amount of nitrogen; and a cloud layer made up of sulphuric acid.
In short, Venus? Not a top holiday destination, really.