Dictionaries define it as another name for the planet Mars (Maṅgala; Mangala). The word aṅgāra (angara) refers to the scarlet or red colour. The planet Mars is known for its bright red hue. It has been mentioned in Sabhāparva (Sabhaparva) of Mahābhārata (Mahabharata) that Aṅgāraka (Angaraka) or Mars had earned a remarkable position in Brahmā’s (Brahma’s) court.
Various Purāṇas (Puranas) provide detailed descriptions about Mars. In Garuḍapurāṇa (Garurapurana) the eulogy of Viṣṇu (Vishnu), recounting his one thousand names, equates the name Aṅgāraka with Viṣṇu, the cosmic figure. In the incantations of his mediation and prayer, Aṅgāraka has been identified as the son of Pṛthivī (Prithivi) or Kṣiti (Kshiti), namely the Earth. Mars or Aṅgāraka is the lord of the zodiacal signs of Aries and Scorpio —
One should worship the blood-red Aṅgāraka in the south-east corner.
According to astrological thought in Purāṇas, the duration of the phase of influence (daśa; dasha) of Aṅgaraka or Mars is eight years — aṣṭāvaṅgārakecaiva. The retrograde position of this planet was a cause of concern even during the age of Mahābhārata. Especially, a retrograde Mars under the influence of the star Maghā (Magha; Regulus according to Western astrology) made people even more apprehensive — maghāṣvaṇgārako bakraḥ śravaṇe ca bṛhaspatiḥ.
It so happened once that Arjuṇa fought the Saṃsaptaka (Sangsaptaka) warriors, and then engaged in battle with other adversaries. After this he once again came to fight the Saṃsaptaka soldiers. This incident in Karṇaparva (Karnaparva) has been compared to Aṇgāraka or Mars being retrograde once, then gaining direct motion, and then reverting back to the retrograde mode.