Evening star. [volume] (Washington, D.C.) 1854-1972, 1900-02-03
FEBRUARY SKIES
Mighty Orion Has Just Crossed the
Meridian.
LOCKYER'S THEORY OF TIE NEBULA
What Photography Has Done for
Star Study.
THE SPLENDoR OF VENUS
Written for The Evening Star.

] written 1or Inc Evening star.
The central figure among the constel-
lations on a midwinter evening is Orion
the mighty Orion as he was styled by
Homer centuries ago; the stormy Orion"
I as he was called by the Romans of a later
period. At o'clock tonight this grand
| X-like figure will have just crossed the
| meridian and stands before us as we face
| the south.
Orion is not only splendid constella-
| ton, attractive to the ancient star gazers
| because of its striking and suggestive fig
| ure. and brilliant with stars, of which two
| are of the first magnitude, but it has prov
| ed to be region of especial interest to
| astronomers. Foremost among its attrac-
! tons is its great nebula. This mysterious
| object, invisible to the naked eye and hard
| ly discernible through opera glass,
| stands at the lowest angle of q very no.
| ticeable diamond-shaped figure, of which one
| side is formed by the three stars of the
| belt-the Three Kings" Viewed through
a telescope it is mist-like blotch on the
| dark background of the sky, of about half
! triangular shape, its brightest portion be-
| ing on its eastern side, while in all other
| directions it fades away gradually to i'm
| perceptibiiity.
What is a NebuIa.
The spectrosccpe has furnished conclu-
| sfve evidence that the faint glow of a neb-
| ula comes from matter in gaseous state.
At the same time it has shown that this
! ghost-like object is something quite differ
ent from the intensely hot fire mist" re-
| quired by the nebular theory of Laplace
| and Herschel The spectroscope indicates
| that the nebula is at a low, not a high
| temperature; and, moreover, it finds in the
| nebula usually not more than two gases
| of which one is hydrogen and the other
| may be nitrogen or, more probably, mag
| resium. The Orion nebula contains also
| helum and a few other gases, some of
| which have not yet been identified with
any terrestrial elements. Equally interest
| ing with the testimony furnished by the
spectroscope Is that of photography. The
| hne photographs of nebulae which have
| been obtained by several astronomers in
| the last six or eight years reveal these
mlst-like objects with distinctness who'll
y unattalnaole by the eye when viewing
| them directly through a telescope. and
| snow them to be full of structural details
| curVlng W1SpS and whorlS-whlch sneak
plainly OF turbulence within them, as if
| Ihey were r1Ven and torn and twisted by
| forces. which act like mighty whirlwinds
| What Is 1t that is whirling?
The MeteOrftic Theory.
| The theory Of the nebula which seems
| now to AFFORD the most satisfactory ex-
p:anation Of the facts revealed by the spec-
troscone and by photography is the me
teoritic theory of Sir Norman Lockver
| Briefly stated, 1t Is this:
| SPACE abounds in non-luminous particles
or small masses of solid matter, such as
| occasionally dash into the earth,s atnos
| pierre, and, being heated by the friction of
| the air, give rise to the familiar spectacle
| OF the meteor or shooting star. Here and
mere, II Is supposed. are enormous aggre-
| sations OF taese tiny bodies-bits of stone
| ana metal-forming clouds of what NAV
| aptly be called cosmic dust. Like all things
| else In the universe, these clouds or streams
i a a in ioy,
| cumstances they are invisible. But SUM-
| pose That two or more of them collide
| Drawn together by their mutual attraction
| The inevitable result will be a commotion
| among the meteorites Great eddies will
be set up among them. which, if visible
| would present just such appearance as
are brought out in the photographs of
nebulae.
The Nebulous Glow.
And now comes the explanation of the
| nebulous glow. These whirlng meteorites
| collide with one another, and the force Of
| their impact generates heat sufficient to
| vaporize and render luminous their more
| volatile substances, or the glow may be
partly electrical. 1t will be the brightest
| where the disturbance is the greatest and
| the collisions are the most frequent and
| violent; while wherever there is regular
| ity of motion-where the meteorites are
streaming in the same direction-there will
| be few or no collisions and there will be
darkness. In viewing nebula, then-that
| in Orion, Say-we are to conceive that we
| see only disturbed portion of one of these
vast shoals of meteorites; in other words,
| that we see only the whirlpool that has
| been set up in Its midst, and which may
also be supposed to be center of attrac-
ton toward which there is indraft of
| this invisible meteoritic matter from ali
directions.
The Birth of Worlds.
The nebula is supposed to be condensing
| under the force of gravity and to be grow
| ing hotter. 1t is. in fact, the embryo of a
| future sun or of suns. time will come
| when the meteorites in its de,ser part-the
| hottest part Of this grand celestial furnace
| will become molten; then they will be-
| come gaseous. But when these stages are
| successfully reached the luminous object
| which they form is no longer a nebula; it
| has become star. At first 1t is red star,
| with a peculiar spectrum" such as that of
| the star Betelguese, in the right shoulder
| of Orion, which Lockyer holds not to be a
| sun, but g. dense and condenslng mass OF
| meteorites." Then, as its heat increases, it
will become yellow star; then a blue
white star. with q spectrum strongly mark
| ed by the lines of hydrogen. such u star as
| Sirius. its matter being now wholly gaseous
| possible temperature. After that 1t will. in .
the course Of ages. cool until it again be-
| Genes a yellow star, with a spectrum like
| that of the sun, indicative of atmos-
| phere consisting of intensely heated gases
| and the vapors of metals. Then it will be-
| come again q red star, surrounded by an
| atmosphere consisting largely of carbon.
Finally its light will be extfnguished; Il