In: Physics
Ephemeris is a book which has data on the position of heavnly objects, primarily planets, constellations, important stars. In southern india it is called panchangam which has tables of five details about the day. 5 details are
what star is there with moon(nakchatra),
what is moon phase (thithi),
Half time of moon phase(karana)
The angle between moon and sun ( yoga)
And day( Sunday - Saturday)
It also has the details about when will a planet move from one constellation to another,Events of Saturn(sani), jupiter(guru) , solar eclipsce( ragu) and lunar eclipse(kedhu) moving from one constellation to another is much celebrated in India with fear. when will lunar and solar eclipse will happen. This habit of creating panchangam dates back to several 1000 years to the very dawn of hinduism. Without knowledge of kepler’s law and newton’s law or without any telescope at he moment, how the people foretold these details is a mystery. Even to this date it is in almost every indian household to find auspicious timing of the day. People usually store old Ephemeris for many generations in india.
In 2005 mars started from Taurus constellation and finished near Pisces constellation . in the mean time it retrograded for a period of two months near constellation cetus.