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Bibliography, web links and some definitions


This section contains references used in the preparation of this website and which may be useful for further reading.

Excellent descriptions of Mars are available in several books, such as:

  • Cattermole P., Mars, The Mystery Unfolds, 2001, Terra Publishing, 186 pp.
  • Carr M.H., Water on Mars, 1996, Oxford University Press, 229 pp.
  • Carr M.H., The Surface of Mars, 1981, Yale University Press, New Haven, 232 pp.

For a book that includes up to date papers on various aspects of Mars research including the radiometric dating and ejection ages, see

  • Kallenbach R., Geiss J. and Hartmann W.K. (editors) Chronology and Evolution of Mars, Kluwer, Dordrecht, 498 pp.

      Two of the papers in this volume are:
    • Nyquist L.E., Bogard D.D., Shih C.Y., Greashake A. and Stoffler D. (2001) Ages and Geologic Histories of Martian Meteorites.

    • Bridges J.C., Catling D.C., Saxton J.M., Swindle T.D., Lyon I.C. and Grady M.M. (2001) Alteration assemblages in Martian Meteorites: Implications for near-surface processes.

Web sites

Some definitions used in this website

  • Aerocentric Longitude (Ls): The angle of Mars in its orbit around the Sun, measured from the line of equinoxes. Ls values are used to denote martian seasons e.g. Ls = 0o is the vernal (spring) equinox within the northern hemisphere and the autumn equinox within the southern hemisphere.
  • Albedo: The fraction of incoming light reflected from a body. Surfaces of high albedo appear white and areas of low albedo appear black.
  • Aphelion (synonym apogee): The point in the orbit of a body where it is furthest from the Sun
  • Celestial Equator: This is the extension into space of the plane of the Earth's equator. (see also Equinoxes)
  • Ecliptic: The plane on which the earth rotates around the Sun. The other planets and asteroids orbit close to this plane, deviations from it are known as Orbit Inclination.
  • Equinoxes: The line of intersection between the Sun's orbit on the Ecliptic and the Celestial Equator is called the line of equinoxes. It is often used as a reference line in astronomical measurements. At a time of equinox e.g. when the Sun's path crosses the Celestial Equator day and night are of equal length.
  • Obliquity: The angle between the plane of a planet's equator and the plane of the planet's orbit around the Sun. The Earth has an obliquity of 23.5 degrees.
  • Opposition: The close approach of Earth and another one of the 6 planets that is further out in the Solar System. For instance, when Earth passes between Mars and the Sun, Mars is said to be at opposition.
  • Orbital eccentricity: A measure of the elongation of an elliptical orbit. Circular orbits have an eccentricity value of zero.
  • Perihelion (synonym perigee): The point in the orbit of a body where it is nearest to the Sun.
  • Revolution Period: the time taken for a planet to orbit the Sun e.g. one year for the Earth, 1.9 times this for Mars. Similarly, the Moon orbits the Earth with a revolution period of 27.3 days.
  • Rotation Period: the time taken for a planet or moon to complete one full rotation on its spin axis e.g. one day for the Earth, 0.41 times this for Jupiter. Similarly, the Moon completes one full rotation on its spin axis in a Rotation Period of 27.3 days.
  • Semimajor axis: The semimajor axis of a planet's orbit is the mean distance of the planet from the Sun. It is often quoted in AU (astronomical units) with the Earth semimajor axis = 1.0.


Mars and Martian Meteorites / John Bridges / October 2003