[therealbilly]

Even worse, what happens when you get to your destination? Will you find a perfect analog of Earth and with the same kind of star? Assuming the star is very similar to our Sun, then you can ask about the atmosphere of the planet. Pretty much you need 25% oxygen and 75% nitrogen and 14 pound per square inch pressure on the surface. Fine, is the gravity the same? If not, there may be problems getting around. Okay, so what about food? You don't want to die of hunger. Finally, what about viruses and bacteria on the planet? They may attack you instantly and you die a miserable death in two weeks. At that point you may say to your self, Why did I come here.

[Ekaros]

Viruses and bacteria would not really be my worries. Unlikely they are compatible with our physiology. Maybe bacteria in sense of flesh eating or producing toxins as by-product, but nothing as infection I think.