**Daily Planetary Distance and Light-Time Tables**

These programs compute the geocentric and heliocentric distances and light-times to the major planets. The distances to the planets are given in AUs (astronomical units) and millions or billions of kilometers or statute miles at 00h TD on each date of the given year and month on either the Julian or Gregorian calendar. These computations are based on the VSOP87 theory.

**SYMBOLS USED IN THE TABLES**

**AU** = Astronomical Units

**Mkm**, **Bkm** = Millions, Billions of kilometres

**Mmi**, **Bmi** = Millions, Billions of statute miles

**UT** = Universal Time (UTC1)

**TD = UT + ΔT** = Dynamical Time (Technically, Barycentric Dynamical Time)

The barycentre is the centre of mass of the solar system.

**ΔT** = Time adjustment made to UT to obtain Dynamical Time (TD).

Due to its random nature, the exact value can only be determined by observation. Generally, it changes at a slow rate and can be approximated, in some cases, based on observed trends.

**NOTE**: For clarity:

1 million = `1E+6`

= 10^{6} = 1 000 000

1 billion = `1E+9`

= 10^{9} = 1 000 000 000

**© Jay Tanner - NeoProgrammics - 2014**