Deimos. Phobos.
Mean long. 1894, Oct. o.o G.M.T 186.25° 296.13°
Mean daily motion (tropical) 285.16198° 1128.84396°
Mean distance ([Delta] = 1) 32.373´´ 12.938´´
Long. of pericentre, ([pi] + N) 264° + 6.375°t 14° + 158.0°t
Eccentricity of orbit 0.0031 0.0217
Epoch for t 1900.0 1900.0
BIBLIOGRAPHY.--Flammarion, _La Planète Mars et ses conditions
d'habitilité_ (Paris, 1892), embodies so copious a _résumé_ of all the
publications and drawings relating to Mars up to 1891 that there is
little occasion for reference in detail to early publications. Among
the principal sources may be mentioned the _Monthly Notices_ and
_Memoirs_ of the Royal Astronomical Society, the publications of the
Astronomical Society of the Pacific, especially vols. vi., viii. and
ix., containing observations and discussions by the Mt Hamilton
astronomers, and the journals, _Sidereal Messenger, Astronomy_ and
_Astrophysics_ and _Astrophysical Journal_. Schiaparelli's extended
memoirs appeared under the general title _Osservazioni astronomiche e
fisiche sull' asse di rotazione e sulla topografia del pianeta Marte_,
and were published in different volumes of the _Memoirs_ of the _Reale
Accademia dei Lincei_ of Rome. The observations and drawings of Lowell
are found _in extenso_ in _Annals_ of the Lowell Observatory. Lowell's
conclusions are summarized in _Mars and its Canals_, by Percival
Lowell (1906), and _Mars as the Abode of Life_ (1909). In connexion
with his work may be mentioned _Mars and its Mystery_, by Edward S.
Morse (Boston, 1906), the work of a naturalist who made studies of the
planet at the Lowell Observatory in 1905. Brief discussions and
notices will also be found in the Lowell Observatory _Bulletins_. The
optical principles involved in the interpretations of the canals are
discussed in recent volumes of the _Monthly Notices, R.A.S_., and in
the _Astrophysical Journal_. In 1907 the veteran A. R. Wallace
disputed Lowell's views vigorously in his _Is Mars Habitable?_ and was
briefly answered by Lowell in _Nature_, who contended that Wallace's
theory was not in accord with celestial mechanics. (S. N.)