What if Earth was like Mars?

The atmosphere is incredibly thin, and the pressure is so low that if you were to go outside without a protective suit, the water in your eyes would instantly vaporize, and then the rest of the water in your body would start doing the same. <br><br>Earth is a terrestrial planet that has no atmosphere, and it is covered in craters. There is no liquid water present on the surface, but scientists are pretty sure there used to be. <br><br>The average temperature on Earth is around -70 degrees Celsius. <br><br>Humans do not live in this solar system, but in another one. <br><br>They are just visiting Earth out of curiosity. <br><br>What do they find?