Good Planets are Hard to Find

Comparison of the atmospheres of Earth, Venus and Mars

Ever wonder why Earth is “just right” for us and all other living things, when our closest planetary neighbors – Venus and Mars – are so inhospitable? The fairytale of “Goldilocks and the Three Bears” provides some clues.

Goldilocks wandered into the 3 bears' home trying out chairs, bowls of porridge and beds, to find just the right comfortable conditions for her. When it came to picking the porridge that suited her, she didn’t take the one that was “too hot” or the one that was “too cold.”

It turns out that Earth’s conditions are just the right ones for us. Our planet is habitable, in large part, because we have a global temperature of 59 degrees Fahrenheit (15 degrees Celsius). Earth is not too cold, like Mars, with frigid average temperatures of -76 degrees Fahrenheit (-60 degrees Celsius) or too hot, like Venus, sweltering at 900 degrees Fahrenheit (482 degrees Celsius).