AlexChan wrote:I just have a question..
That 2 moons are irregular body?
Given their small size, it's unlikely that they're spherical - they're probably asteroidal in shape.
Malenfant wrote:AlexChan wrote:I just have a question..
That 2 moons are irregular body?
Given their small size, it's unlikely that they're spherical - they're probably asteroidal in shape.
PlutonianEmpire wrote:A screenshot I made of the new moons
The evil twin moons of Pluto! *scary music*
SittingDuck wrote:Is there a minimum size for a planet for it to indefinitely (well, lets say 5 billion years) hold on to its atmospherew ithout it slowly leaking away. Well..lets just say with an earth like atmosphere.
Malenfant wrote:SittingDuck wrote:Is there a minimum size for a planet for it to indefinitely (well, lets say 5 billion years) hold on to its atmospherew ithout it slowly leaking away. Well..lets just say with an earth like atmosphere.
It depends on several things - the mass of the planet, the molecular weight of the gas, and the temperature at the base of the exosphere (the highest level of the atmosphere, where the atoms can fly off into space), which is partly determined by the temperature of the planet (and distance from the star).
Titan and Triton and Pluto can retain atmospheres basically because they're so cold. If you moved them to Earth's orbit, they'd rapidly lose their atmospheres.
Scorpiove wrote:Yes Titan is the perfect example. It has a thicker atmosphere than Earth only because it is so cold. Mars for example is more massive than Titan yet it still was to warm of a planet to keep most of its atmosphere. But yeah many things contribute to the ammount of atmosphere a planet has. The more massive a planet is the warmer it can be and still have one..... less massive and it will have to be colder. Can't have both!