Navagrahas...

A topic of dispute, between western philosophers (and scientists) and Indian theists of Vedas -

There are basically many divisions and subdivisions in Indian astronomical science,

Graham (a planet)

Moola graham (a bigger planet which controls the other planets, can also be a star)

Nakshathra (a star)

Anthariksha shila (asteroid)

Upagraha or Grahanga (a natural satellite of a planet)

Suryanga (can be a planet or anything around sun or any other star) and so on.

But graham does not just mean a planet, it also signifies the celestial bodies which are spherical by nature, according to Pani and Prakrit (ancient languages of India much ancient than Sanskrit, till known)

Hence in astronomical terms:

Surya is a nakshatra and a moolagraha (moolagraha :who also can be the origin of grahas) and thus no offense including it in the list of navagrahas, as no calculations are performed without its origin and also will have adverse effect in astrological predictions.

Mercury, Mars, Venus, Jupiter, Uranus, Neptune, Saturn are all universally accepted as planets.

Pluto was never considered a planet by Indians and now it’s been the same with western philosophers and scientists too…

Many now might question of moon being considered a graham and earth being eliminated from the list of navagrahas. Bhoomi or Earth was never eliminated from the list at the first place it was always considered a graham and moon a upagraha or grahanga, but for astronomical calculations, to know the effect of grahas and its positions, on man, and to predict natural calamities or epidemic ,the position of earth was also important, but being on earth and to experience its effect due to its planetary position, was quite an impossible task, its like though the surface of sea is rough with waves its bed remains calm, hence being on earth would not let you experience its motion (revolving not rotating) or effects of its position in space. Hence another planet (graha) or upagraha or satellite which almost was equidistant from sun with negligible difference in distance was considered for calculations, thus moon replaced earth in the list.