Titan which is smaller than mars has an atmosphere but mars is not able to maintain atmosphere. Even Luna doesn't have an atmosphere.
Apparent magnitude is a rather complex way to determine the brightness of a star. Quoting the introduction text from the linked to Wikipedia page: The apparent magnitude (m) of a celestial body is ...
How can you determine the gravitational force needed to keep a particular gas in the atmosphere of a planet (for example, carbon dioxide (CO2))? I came across the following formula ...
Since the moon has gravity, it's almost impossible that there aren't some gasses trapped on the surface by the moon's gravity. Has any free-floating oxygen been found on the Moon? If so, in what ...