In vedic times, Boomi (Earth) was known by the name of 'Prithvi'. To this prithvi, was born Agni, the god of fire.

According to some texts, the planet Mars (Chevvai in Tamil, Angarak in Sanskrit) was said to be born to 'Boomi' too.

If I am correct, it is said, in Ramayana, Sita devi is said to have requested Agni to punish her if she had any mistakes on her, regardless of the fact she was his mother (as Sita was an incarnation of Booma or mother earth).

Therefore, my question here is, what is the connection between earth (boomi) and the fire element? I am also thinking of the sign of Capricorn which is an Earth sign and Mars is exalted in this sign.

(Incidentally, Boomi was always born 'Ayonijah' or self-incarnate. Be it Sita, Andal (who is said to be Boomi's incarnation). This makes me wonder if Boomi has a strong connection with the fire element, and hence Booma devi is born self-incarnate always, may be she doesn't want to be cooled-down? Even Skanda, the embodiment of fiery Mars the red planet, is born from Lord Shiva's 3rd eye and not of a mother. ).

Knowledgeable, kindly answer my question in highlight.