nkev, predominantly comprised ntawm methane nrog ib molecular luj ntawm 16, teeb dua cua, Uas muaj ib tug molecular luj ntawm kwv yees li 29 Vim nws cov thawj txaus ntawm nitrogen thiab oxygen. Qhov txawv hauv molecular luj ua tej nkev tsawg dense thiab ua rau nws sawv hauv ib cheeb tsam atmospheric.