Editing Chandra (section)

==Astronomy==

Soma was presumed to be a planet in Hindu astronomical texts.<ref>{{cite book|author1=Aryabhatta|author2=H. Kern (Editor, Commentary)|title=The Aryabhatiya|url=https://books.google.com/books?id=z8EUAAAAIAAJ |year=1973|publisher=Brill Archive |language=sa, en|page=xx}}</ref> It is often discussed in various [[Sanskrit]] astronomical texts, such as the 5th century ''Aryabhatiya'' by [[Aryabhatta]], the 6th century ''Romaka'' by Latadeva and ''Panca Siddhantika'' by Varahamihira, the 7th century ''Khandakhadyaka'' by Brahmagupta and the 8th century ''Sisyadhivrddida'' by Lalla.<ref name="Burgess1989vii">{{cite book|author=Ebenezer Burgess|editor=P Ganguly, P Sengupta|title=Sûrya-Siddhânta: A Text-book of Hindu Astronomy|url=https://books.google.com/books?id=W0Uo_-_iizwC|year=1989|publisher=Motilal Banarsidass (Reprint), Original: Yale University Press, American Oriental Society|isbn=978-81-208-0612-2|pages=vii–xi}}</ref> Other texts such as ''Surya Siddhanta'' dated to have been complete sometime between the 5th century and 10th century present their chapters on various planets with deity mythologies.<ref name="Burgess1989vii"/> However, they show that the Hindu scholars were aware of elliptical orbits, and the texts include sophisticated formulae to calculate its past and future positions:<ref name=burgessxx>{{cite book|author=Ebenezer Burgess|editor=P Ganguly, P Sengupta|title=Sûrya-Siddhânta: A Text-book of Hindu Astronomy|url=https://books.google.com/books?id=W0Uo_-_iizwC|year=1989|publisher=Motilal Banarsidass (Reprint), Original: Yale University Press, American Oriental Society|isbn=978-81-208-0612-2|pages=xx}}</ref>

:The longitude of Moon = <math> m - \frac{P \times R \sin (m - a)}{360} </math>
:– ''Surya Siddhanta'' II.39.43<ref name=burgessxx/>
:where ''m'' is the Moon's mean longitude, a is the longitude at apogee, P is epicycle of apsis, R=3438'.