Rahu ketu story in Ramayana

Now a days, we have been reading/hearing the story of Mohini Avatar and separation of rāhu (राहु) and Ketu (केतु).

As per the story, Sun and Moon were responsible for the beheading of the demon. Hence it is said the rāhu treats Sun and Moon as his biggest enemies. That is the reason, conjunction of rāhu with Sun and Moon is bad in horoscope. Also, as per the story, periodically rāhu will swallow the Sun and Moon. That means it will cause eclipse to the Sun and Moon.

This is a Puranic story.

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Srimad Ramayana, which came into existence much earlier to Puranas, does contain the story of Samudra Manthan in the 45th Sarga of Bala Kanda.

However, it does not contain the story of beheading of Asura called Svarbhānu, and his head and remaining body becoming rāhu and Ketu.  It simply says that all asuras were eliminated.

यदा क्शयम् गतम् सर्वम् तदा विष्णुः महाबलः।

 अमृतम् सः अहरत् तूर्णम् मायाम् आस्थाय मोहिनीम्॥ १-४५-४२

"When everything is wading into annihilation then that omnicompetent Vishnu swiftly impounded Amrita, the Divine Elixir, by assuming his illusory power of Mohini."

अदितेः आत्मजा वीरा दितेः पुत्रान् निजघ्‌निरे।

 अस्मिन् घोरे महायुद्धे दैतेया अदित्यायोः भृशम्॥ १-४५-४४

"In this horrendous war between the progeny of Diti, namely demons, and the progeny of Aditi, namely gods, the sons of Aditi being gods, have altogether massacred the demonic sons of Diti.

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This indicates that the people of Vedic literature did not believe the story of rāhu and Ketu and Eclipse related story of rāhu and Ketu.

The Puranic story of Sri Hanuma flying into the sky for catching the Sun, under illusion that it was a Red fruit, his thrashing rāhu, who was about to swallow the Sun during the Eclipse time, does not find place in Srimad Ramayana.

The Kishkinda Kanda tells about Sri Hanuma flying into the sky.

शतानि त्रीणि गत्वा अथ योजनानाम् महाकपे |

तेजसा तस्य निर्धूतो न विषादम् ततो गतः || ४-६६-२२

"Even on your flying up three hundred yojana-s, oh, brave monkey, and even when sun's radiation puffed and blown you down, you did not get into any anguish as were indefatigable."

 त्वाम् अपि उपगतम् तूर्णम् अंतरीक्षम् महाकपे |

क्षिप्तम् इन्द्रेण ते वज्रम् कोप आविष्टेन तेजसा || ४-६६-२३

"Oh, mighty monkey, even on seeing you who are coming near the vault of heaven, Indra is captivated by anger and by his effulgence he catapulted his Thunderbolt at you."

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It does not mean that there was no mention about rāhu related eclipse in Srimad Ramayana.  There was indeed a mention about rāhu related Moon eclipse in Sundara Kanda of Srimad Ramayana.

वेदीमिव परामृष्टां शान्तामग्निशिखामिव |

पौर्णमासीमिव निशां राहुग्रस्तेन्दुमण्डलाम् || ५-१९-१५

Seetha was like an altar desecrated, like a tongue of fire gone out, like a full moon night with moon devoured by rāhu.

आस्ये तस्या निमज्जन्तं ददृशुः सिद्धचारणाः |

ग्रस्यमानं यथा चन्द्रं पूर्णं पर्वणि राहुणा || ५-१-१९३

Siddhas and Charanas saw Hanuma sinking in her mouth, like the full moon on a full moon day being swallowed by rāhu.

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In Rig Veda, there was no mention about moon/sun eclipse by rāhu, as mentioned in puranas.  

a)    However, a mention about an Universal deluder bṛsaya (बृसय)  was made in Rig Veda 6.61.3 - विश्वस्य मायिनः

सरस्वति देवनिदो नि बर्हय प्रजां विश्वस्य बृसयस्य मायिनः । 

उत क्षितिभ्योऽवनीरविन्दो विषमेभ्यो अस्रवो वाजिनीवति ॥

Sarasvatī, tear down the scorners of the gods, the offspring of every  universal deluder Br̥saya.  And (while) you found streambeds for the settlements, you flowed poison for them, o you rich in prize mares.

b)   In Rig Veda 5.40.5  Āsura Svarbhānu was mentioned as covering Sun with darkness.  However, if understood in spiritual connotation, it may mean engulfing of ignorance in a human.

यत्त्वा सूर्य स्वर्भानुस्तमसाविध्यदासुरः । 

अक्षेत्रविद्यथा मुग्धो भुवनान्यदीधयुः ॥

When, o Sun, Svarbhānu Āsura pierced you with darkness,  like a befuddled man not knowing the territory did the living beings perceive

c)    On the other hand, Ketu is mentioned in Rig Veda, but with a spiritual connotation  as illumination or higher consciousness or SELF REALISATION.  

Shri Aurobindo says as follows;

This perception, this vision is, we are told, that of the Immortality, amṛtasya ketuḥ - अमृतस्य केतुः (Rig Veda 3.61.3); it is the light, in other words, of the Truth and the Bliss which constitute the higher or immortal consciousness. 

Night in the Veda is the symbol of our obscure consciousness full of ignorance in knowledge and of stumblings in will and act, therefore of all evil, sin and suffering; light is the coming of the illuminated higher consciousness which leads to truth and happiness. 

We find constantly the opposition of the two words duritam and suvitam. Duritam means literally stumbling or wrong going, figuratively all that is wrong and evil, all sin, error, calamity; suvitam means literally right or good going and expresses all that is good and happy, it means especially the felicity that comes by following the right path.