u/Similar_Tension6322

Hi r/astrophysics, I previously asked a much more broad version of this question, which turned out to be way too hard to answer. Hopefully this is a little more "possible" haha.

That being said:

Do all planetary bodies which become spherical later begin spherically, OR is it possible for the early stages of many planets to be irregularly shaped, until more mass is accumulated?

For example, in the very first/early stages of a planet's formation, would we be looking at something sort of bumpy, potato shaped, and not-very-round? Or would we be looking at something spherical right off the bat, albeit very small?

If it IS possible for something irregularly shaped to then accumulate mass until it's gravitational force forces it round-- what are the chances of an asteroid or planet-shard becoming a planet?

Thank you for taking the time to read! Hopefully this wasn't too confusing. I haven't been able to find any answers online and would appreciate any insight, however small.

Hi r/astrophysics, I've been thinking about this for a few days. There's a few questions here, so bear with me.

Firstly, do all planetary bodies which become spherical begin spherically, or are the early stages of many bodies irregularly shaped, until more mass is accumulated?

Next, why aren't some of even the largest asteroids then, for example, not spherical? Where's that "tipping point" in size, volume, and mass that causes a spacial object to become (or begin) a spherical shape?

Lastly, is it possible for an irregularly shaped, non-round body to become spherical later due to mass accumulation?

Thank you for taking the time to read. Really looking forward to the answers.

Hi, I posted this in r/AskAstrophysics as well, but wasn't sure where it belongs so putting it here too!

Recently I've been researching Titan, one of Saturn's very popular moons, with an atmosphere of 95% nitrogen, %5 methane, and trace amounts of other carbon-rich compounds. Supposedly, the sun's ultraviolet light breaks down nitrogen molecules in the atmosphere, which recombine to form a variety of organic compounds. This sparked the question:

What gives an exoplanet its gaseous atmosphere? And why are those atmospheres most often some combination of methane, nitrogen, and carbon dioxide? Why aren't there any other oxygen-rich atmospheres out there, or chlorine, or neon? Maybe there are, and I just don't know about it!

Would love to know more about atmosphere types and what makes some more common than others.

Hi, this is my first question here!

Recently I've been researching Titan, one of Saturn's very popular moons, with an atmosphere of 95% nitrogen, %5 methane, and trace amounts of other carbon-rich compounds. Supposedly, the sun's ultraviolet light breaks down nitrogen molecules in the atmosphere, which recombine to form a variety of organic compounds. This sparked the question:

What gives an exoplanet its gaseous atmosphere? And why are those atmospheres most often some combination of methane, nitrogen, and carbon dioxide? Why aren't there any other oxygen-rich atmospheres out there, or chlorine, or neon? Maybe there are, and I just don't know about it!

Would love to know more about atmosphere types and what makes some more common than others.