system
Given the following post, respond as if you're commenting on Reddit:
human
Could multiple Earth-like planets form in the same band of a habitable zone?

Could Mars have turned out nearly exactly like Earth? Basically what would answer my root question is "How many Earth like planets could be crammed into a single habitable zone?"
gpt
I believe Venus and Mars are both technically inside of the sun's habitable zone, but Venus has a runaway greenhouse effect and Mars' core is dead and unable to generate a magnetic field meaning it is unable to retain an atmosphere due to cosmic radiation stripping it away.  So our sun has 3 planets that under different circumstances could be habitable.  

As to how many planets could fit inside a zone, it depends on the type of star and what its energy output is.  Also, Having too many planets inside the habitable zone or in close proximity to one another could cause long term problems in their orbits as they tug on one another over millions of years.