The second planet from the sun, Venus, was once actually a lot like Earth until a runaway greenhouse effect dried up all the oceans and left the planet hot and dry. So world-famous physicist Stephen Hawking is offering to send climate change deniers to the planet on his own dime to try and convince them of climate change here on Earth.

Anyone who traveled to Venus would find a hot planet, that spins from east to west, has no moon, an incredibly thick atmosphere of carbon dioxide and clouds of sulfuric acid. The planet is only slightly smaller than Earth and has a similar structure, according to NASA.

The thick atmosphere traps heat and makes it incredibly warm on the planet. The surface of the planet reaches temperatures hot enough to melt lead, says NASA. Venus also has a core, with a hot churning rocky mantle and a crust like Earth does. Billions of years ago it even may have had oceans and habitable surface temperatures, said NASA, but that all changed with the runaway greenhouse effect.

In a new episode of Stephen Hawking’s Favorite Places he says of climate deniers, "Tell them to take a trip to Venus. I will pay the fare," CNET reported. The idea behind his offer is that Venus underwent its own sort of climate change and might offer some insight about what Earth could go through.

A "runaway greenhouse" happens when a planet takes in more energy from the sun than it can expel which results in the surface of the planet warming, which speeds up the warming process further. This happens because as the planet warms, so does the ocean, putting more water vapor into the atmosphere, resulting in even more trapped heat, perpetuating the cycle further.

Hawking has been vocal in the past about how much time humans have left on Earth and he’s said humans need to be on other planets within the next 100 years or so. He’s also said that he doesn’t think humans will survive more than 1,000 years on Earth without traveling to other planets.

Of course, it's physically impossible to send a live person all the way to Venus, but the principle of Hawking's statement is clear.

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