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by Her Majesty's Nautical Almanac Office,
494 pages, 6 by 9 inches, hardbound,
includes CD-ROM with ASCII tables, 2Lbs 5 Ozs. ship wt.

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Planetary and Lunar Coordinates 2001-2020 provides essential information for those people who require low-precision astronomical positions of the Sun, Moon and planets for tasks such as the planning of observations and the computation of cometary orbits well into the future. It is prepared jointly by HM Nautical Almanac Office at Rutherford Appleton Laboratory and the Nautical Almanac Office of the United States Naval Observatory.

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Phenomena for the Sun, Moon and planets are provided starting with solar and lunar eclipses for a twenty-year period, listed in chronological order and by type, followed by visibility maps (Lunar and Solar) and timing information. Principal phases of the Moon in UT to the nearest minute are tabulated as well the instants when the Moon is nearest to (perigee) and furthest from (apogee) the Earth. The astronomical seasons and the instants when the Earth is closest to (perihelion) and furthest from (aphelion) the Sun are given to a similar precision. Dates for the passage of the Earth through the ring plane of Saturn providing optimum views of the Saturnian satellites as well as the dates for the rare transits of Mercury and Venus across the Sun are listed.

Greatest elongations for Mercury and Venus are provided to the nearest hour. Oppositions, conjunctions and stationary points for the superior planets are given to the same precision. The section on Observability Data provides the transit time, the elongation of the planet from the Sun and the visual magnitude for Mercury, Venus, Mars, Jupiter and Saturn at ten-day intervals and for Uranus, Neptune and Pluto at forty-day intervals.

The coordinates of the planets Mercury, Venus, Mars, Jupiter, Saturn, Uranus, Neptune and Pluto are tabulated for four coordinate systems:

  1. geocentric equatorial spherical coordinates, i.e. right ascension, declination, and light-time
  2. heliocentric equatorial rectangular coordinates
  3. geocentric ecliptic spherical coordinates, i.e. longitude, latitude, and distance
  4. heliocentric ecliptic spherical coordinates, i.e. longitude, latitude, and distance
If geocentric coordinates are tabulated, the position of the Sun is also provided. Likewise, if heliocentric coordinates are tabulated, the position of the Earth/Moon barycentre is also provided.

Geocentric and heliocentric positions of Mercury are given at five-day intervals to a precision of 0h.001 in right ascension, 0°.01 in declination, longitude and latitude and 0.001astronomical units (au) in rectangular coordinates and distances. For the Sun and the remaining planets right ascension is given to 0h.0001 and declination, longitude and latitude to 0°.001 and 0.0001au in rectangular coordinates and distances. Light times are given in micro-days (approximately 0s.1) which can be used directly in the calculation of the corrections for aberration. The tabulation interval is ten days or forty days for Uranus, Neptune and Pluto.

Geocentric positions of the Moon are given daily to a 0h.001 in right ascension and 0°.01in declination, longitude and latitude. The tabulation also includes the elongation of the Moon from the Sun at 0h and the transit time as well as rectangular coordinates given in units of 10-7 au. Formulae and constants for the computation of horizontal parallax and semi-diameter are given with other data for the Moon.

Rectangular coordinates of the barycentre and the indirect attractions of the planets on the Sun, which may be used in the numerical integration of cometary orbits, are tabulated at ten-day intervals.

The tabulated coordinates of the Sun, Moon and planets were derived from fundamental ephemerides computed at the Jet Propulsion Laboratory, Pasadena, California and are given relative to the equinox and equator or ecliptic of J2000.0.

The companion CD-ROM to this book contains computer readable ASCII files of the planetary and lunar coordinates. The ASCII files are similar to the tabulated data but without column headings, gaps or pagination and Julian dates are given in full. A file giving the structure of these files is provided.