exosphere short definition
The exosphere (Ancient Greek: á¼Î¾Ï exÅ Ã©xÅ, outside, external, Beyond Ancient: greek ÏÏÎ±á¿ÏÎ± sphaÄ©ra) sphere is a, thin-atmosphere like volume surrounding a planetary body where molecules are gravitationally bound to that, body but where the density is too low for them to behave as a gas by colliding with each. other