In astronomy, an ephemeris provides the position of natural and artificial objects in the sky at a given point in time.
From ancient times, the positions of the planets are given as printed values in the tabular format. These attributes tend to change from time to time. Thus, the diary usually lasts till a day only to be replaced by new values on the very next day. Nowadays, the modern ephemerides are calculated electronically with the help of mathematical models of the movement of celestial bodies around the Earth. The printed ephemeris, though obsolete, is still in use in some parts of the world where the computer devices are yet to be made available to the general public.
Ephemeris lists the planetary positions using the spherical polar coordinate system according to the right ascension and declination. These coordinates are widely used in the making of star maps and telescopes. The astronomers are peculiarly interested to know about the timings for the following astronomical events e.g. solar and lunar eclipses, planets retrograde, sidereal times, etc. Ephemeris astrology helps in predicting horoscope as it tells us about the current planetary positions and their impact on the human and terrestrial events.
Ephemeris @year provides you with the planetary position by date, which in turn helps you with the positional description of planets along with their respective stars, natural satellites and, galaxies. These ephemerides usually cover centuries including the upcoming ones as well. This is done with the help of various real-time calculations available in the field of celestial mechanics. However, there are several phenomenons that may not be adequately explained by the modern ephemeris due to the disruption caused by loosely researched asteroids. Ephemerides play a vital role in making the celestial navigation software which in turn helps us with the spacecraft navigation and can work as a backup option for the global positioning system i.e. GPS. For scientific purposes, the planetary position today or right now planetary position is important as it provides us with the necessary information about the position of comets or asteroids at any given point in time.