Saturn, the slow-moving planet takes 30 years to complete the perambulation of the Sun. He is supposed to be the son of Chaya Devi (Shadow) and the son of God. The God of death Yama is his half-brother. He takes 30 months to cross one rasi(one by twelfth of the journey), It is believed that when he occupies the twelfth house, first house, second house from the moon(called sade sathi or seven and a half year sojourn) or occupies the twelfth house from moon, he causes untold and extreme misery. This great prayer occurring in the Brahmanda Purana is believed to be the best possible antidote for such a situation.
Sani Vajra Panjarika Kavacham in English :
Neelambaro, Nelavapu, kireeti, Grdhra sthitha, sthrasakaro, dhanushman,
Chathurbhuja, suryasutha, prasanna, Sada mama syadwaradha prasantha ॥ 1 ॥
Oh god dressed in blue silk, who has a blue body,
Who wears a crown, who sits on vulture,
Who gives misfortunes, who is armed with a bow,
Who has four hands and who is son of Sun God,
Be pleased with me always and happily grant me boons.
Srunu dwam rishaya, Sarva sani peeda haram mahath,
Kavacham Sani Rajasya Soureridhamanuthamam ॥ 2 ॥
Be pleased to hear oh sage, the great armour,
Which is a cure to all misery brought by king Sani,
Who is the incomparably great in the clan of the Sun.
Kavacham devatha vasam vajra panjara samgnakam,
Sanaishara preethikaram, sarva soubhagya dhayagam ॥ 3 ॥
This armour called “thunderbolt shield” in which gods live,
Is very dear to the slow-moving planet, and brings all luck.
Om Sri Sanaischara, pathu bhalam may Soorya nandana,
Nethre Chayathmaja pathu, pathu karnou Yamanuja ॥ 4 ॥
Om, Oh God Saturn, let the son of Sun protect my forehead,
Let the darling son of Chaya protect my eyes,
Let my ears be protected by the brother of Yama.
Nasam Vaivaswaswatha Pathu, mukham may Bhaskara sada,
Snigha kandashasch may kandaam, bhujou pathu Mahabhuja ॥ 5 ॥
Let my nose be protected by Sun God,
Let the illuminator always protect my face,
Let him with a pleasant voice protect my voice,
And let the great armed God protect my arms.
Skandhou pathu sanischaiva, karou pathu shubha pradha,
Vaksha pathu Yama bhratha, kukshim paathvasitha sthadha ॥ 6 ॥
Let my shoulders be protected by Sani,
Let my hands be protected by he who does good,
Let the brother of Yama protect my chest,
And the one who is dark in colour protect my navel.
Nabhim grahpathi pathu, manda pathu kateem thadha,
Ooru mamanthaka pathu, yamo januyugam thadha ॥ 7 ॥
Let my stomach be protected by the lord of all planets,
Let the slow mover protect my hips,
Let he who makes end protect my thighs,
And let Yama protect my pair of knees.
Padou Manda gathi pathu, sarvangam pathu pippala,
Angopangani sarvani rakshen may Surya nandana ॥ 8 ॥
Let my legs be protected by him with slow speed,
Let all my organs be protected by he who wears the coat,
And all my primary and secondary organs,
Be protected by the darling sin of the Sun God.
Ithyethath kavacham divyam padeth soorya suthasya ya,
Na thaasya jayathe peeda, preetho bhavathi sooryaja ॥ 9 ॥
If this armour of the son of the Sun God is read,
No misery will come to him and,
The son of Sun God would be pleased with him.
Vyayay janma dwitheeyastho, mruthyu sthana gatrhopi va,
Kalathrastho gatho vapi supreethasthu sada sani ॥ 10 ॥
Whether Saturn occupies the twelfth, first or second house,
Or even goes to the house of death or occupies the seventh star,
Saturn will always be pleased with him.
Ashtamastha soorya suthe vyaye, janma dwitheeyage,
Kavacham padathe nithyam, na peeda jayathe kwachith ॥ 11 ॥
If the son of Sun God is in the eighth, twelfth, first or second house,
Daily reading this Kavacham, no misery would ever be caused.
Ithyedath kavacham divyam saureya nirmitham pura,
Dwadasahtama janmastha doshan nasayathe sada ॥
Janma lagna sthithaan doshan sarvan nasayathe Prabhu ॥ 12 ॥
This holy divine armour composed by Sun in ancient times,
Would destroy the ills caused by the eighth, twelfth, first and second house,
And also destroy the bad effects of Saturn occupying the Lagna rasi(Ascendant)
Ithi Sri Brahmanda Purane Brahma Narada Samvade,
Sani Vajra panjara kavacham sampoornam,
Thus ends the thunderbolt armour of Saturn,
Occurring in the discussion between Brahma and sage Narada,
In Brahmanda Puranam