In the navagraha sūkta, after āditya comes aṅgāraka or mars, not candra. Hence we may now take up the mantra for aṅgāraka.

The adhidevatā and pratyadhi devatā for aṅgāraka are pṛthvī (the earth) and kṣetrapāla respectively.

kṣetrapāla is a concept of 'protector of the field', the field denoting any area, usually a village. Siva temples have an idol of kṣetrapāla who is depicted as an ugramūrti. There is a belief that "bindumādhava" is the kṣetrapatiḥ of kāśī. (This I remember to have read somewhere, but am not sure.) kṣetrapāla is believed to be an aspect of rudra (bhairava), agni or as an independent deity also.

The first mantra is:

ऋषिः - विरूप आङ्गिरसः ।छन्दः - गायत्री । दॆवता - अग्निः

अग्निर्मूर्धा दिवः ककुत्पतिः पृथिव्या अयम् ।
अपाँ रॆताँसि जिन्वति ॥ --ॠ. वॆ. ८. ४४.१६

ṛṣiḥ - virūpa āṅgirasaḥ |chandaḥ - gāyatrī | devatā - agniḥ

agnirmūrdhā divaḥ kakutpatiḥ pṛthivyā ayam |
apām̐ retām̐si jinvati || --ṝ. ve. 8. 44.16

This agni, who is the greatest of the devas, higher than dyuloka (sky) and ruler of both the dyuloka and the earth, satisfies the moving and unmoving elements (bhūtas).

Note : This is yet another instance of 'some' ṛk being utilised to fulfil the felt need to embellish rituals and prayers with vedic-sounding mantras, without much attention having been given to whether it has any meaning to the purpose for which it is utilised. This mantra (ṛk) has nothing to do with the planet (graha) Mars. agni and aṅgāraka have only the similarity that 'aṅgāra' means charcoal or heated charcoal, besides the probable root ag or ang from which both might have been derived.

Probably, once the texts of the ṛgveda and yajurveda were finalised and subsequently the priests went on inventing new sacrificial and other rites, and and elaborating the existing ones, it became necessary to make do with whatever was available in the already finalised ṛgveda text. So, selections were made if some similarity of words were found, or, sometimes even without regard to such minimum requirements.

ऋषिः - मॆधातिथि काण्व : छन्दः - गायत्री । दॆवता - पृथ्वी

स्यॊना पृथिवि भवानृक्षरा निवॆशनी ।
यछानश्शर्म सप्रथः ॥ --१. २२. १५

ṛṣiḥ - medhātithi kāṇva : chandaḥ - gāyatrī | devatā - pṛthvī

syonā pṛthivi bhavānṛkṣarā niveśanī |
yachānaśśarma saprathaḥ || --1. 22. 15

O bhūmīdevī ! be your wide-spreading, be free from thorns, providing us comfort and expansive shelter.
[The hymn is repeated at the ceremony termed mahānāmnī, at the time of touching the earth].

ऋषिः - वामदॆवः (गौतमः) । छन्दः - अनुष्टुप् । दॆवता - क्षॆत्रपतिः

क्षॆत्रस्य पतिना वयँ हितेनेव जयामसि ।
गामश्वम् पॊषयित्नुवा स नॊ मृडा(ळा)तीदृशॆ ॥ --4. 57. 01

ṛṣiḥ - vāmadevaḥ (gautamaḥ - one view) | chandaḥ - anuṣṭup | devatā - kṣetrapatiḥ

kṣetrasya patinā vayam̐ hiteneva jayāmasi |
gāmaśvam poṣayitnuvā sa no mṛḍā (ḷā) tīdṛśe || --4. 57. 01

Throug the help of kṣetrapatiḥ as our friend (favourably disposed towards us) we conquer the (agricultural) field for the welfare of all living beings. May he bestow upon us cattle, horses, nourishment and with such gifts may he make us happy.