These planets are small and of high density, mainly by transparent and rocky materials with a well differentiated internal structure and a similar size.
They tend to be more dense since it is formed of rocky and non-gaseous materials like the higher planets.
Nitrogen Fixating bacteria ( such as cyanobacteria or clostridum) can convert gaseous nitrogen in the air into amonia, a compound that organism can use to make amino acid and other nitrogen-containing organic molecules
