Could a planet hold a significant atmopshere of Co2 O2 N and H2O if the gravity was 50% Earths if under the right conditions?
So if a planet with this gravity was inbetween earths and mars distance do you think it could hold onto the atmosphere? Id imaine if it were at venuses distance there would be no atmoshpere.
Ok so i made up a hypothetical exoplanet that has a mass of .205 earths with a density of 5.20 g/cm3 and a radius of .60 earths and gravity is 57% earths with an orbit of 402 days around a sun like star. The temperature for the planet is around 275 K Could a planet like this retain a thick enough atmosphere for life? Any possibility for life?
The escape velocity of the planet can be found by:
For your planet, it would be about 6.5 km/s, while earth's escape velocity is about 11.2 km/s.
Using the Maxwell-Boltzmann distribution for the speed of gas particles, you could determine the relative amount of gas you'd expect to lose compared to earth. However, just by taking a look at a plot of the Maxwell-Boltzmann distributions for a few gases at 298°K, you can see that even the lighter gases seem to fit well within the range of your escape velocity.
Without actually going into the math for the Maxwell-Boltzmann probability density, this seems to indicate that a planet of those proportions would be able to sustain an atmosphere similar to earth's. The temperature could even be a bit higher.
It is not. Just look at venus. A magnetic field is relevant, but not required for an atmosphere.And, of course, magnetic field is vital for holding on to the atmosphere. Just look at Mars.
I guess conditions have to be right for an atmosphere, there are certainly a lot of styles of atmospheres in the solar system. But as for active volcanoes, look at Io. There are active volcanoes going on daily, yet it has an atmosphere of 1 billionth of Earth's. So volcanic activity alone is not the whole answer.No such thing as an earth like atmosphere else where as they come in various differences. A earth size planet could have a mars like atmosphere and a mars sized planet could have a venus like atmosphere. I think there are a number of processes that determine what type of atmosphere occours on a planet or moon other than size. Look at titan thick atmosphere then Ganymede no atmosphere despite similar sized. We also have to consider the what the planet or moon is made of and a number of other processes. Mars has 38% Earths gravity yes but the volcanoes are barley active. The planet i created was 57% earths gravity and has active volcanoes.