Great Incarnations

According to Maharshi Parashar the Unborn Lord has many incarnations. He has incarnated as the 9 grahas (Nava Grahas) to bestow on the living beings the results arising from their Karmas. He is Janardan. He assumed the auspicious form of grahas to destroy the demons (evil forces) and sustain the divine beings.
Four incarnations, viz. Rama, Krishna, Narasimha, and Varah are wholly with Paramatmansha. The other incarnations (other than these, out of the ten) have Jivatmansha in them too.
From Surya occurred the incarnation of Rama, from Chandra that of Krishna, from Mangal that of Narasimha, from Buddha that of Buddha, from Guru that of Vamana, from Shukra that of Parashurama, from Shani that of Kurma (Tortoise), from Rahu that of Varah (pig), and from Ketu that of Meena (Fish). All other incarnations other than these are also through the grahas. The beings with more Paramatmansha are called divine beings.
The beings with more Jivatmansha are (mortal) beings. The high degree of Paramatmansha from the grahas (viz. Surya and others), incarnated as Rama, Krishna, etc. After completing the mission, the Paramatmanshas of the grahas merge back into the respective grahas. The Jivatma portions from the grahas take birth as human beings and live their lives according to their Karmas and again merge back in the grahas. At the time of the Great Destruction, the grahas themselves merge in Lord Vishnu.
A person who knows all of these will become versed in the knowledge of the past, present, and future. Without a knowledge of Jyotish these cannot be known. Hence, everyone should have a knowledge of Jyotish, particularly the Brahmin. A person being devoid of knowledge of Jyotish, blaming this Vedic Science, will go to the hell called 'Raurava', and will be born again, but blind.