The main reason for the temperature constraint isn't actually temperature but rather the presence of liquid water. We currently know of no life form that can e

The main reason for the temperature constraint isn't actually temperature but rather the presence of liquid water. We currently know of no life form that can exist without it. I believe the 'goldilocks zone' is more specific in that its looking for liquid water on the surface. There could be liquid water underground in bodies well outside the goldilocks zone and there are some indications that this is true of some moons in our own solar system. 'Planet temperature' doesn't completely rule out the possibility of life. Venus for example is hot as hell on the surface but there is actually a band of the atmosphere which humans could hangout unprotected in, its breathable, the pressure is about what it is on Earth, etc. There have been some attempts to send a probe to hang out there and look for bacterial life but I don't think any have been funded.