El Paso herald. (El Paso, Tex.) 1901-1931, 1917-12-22
Sometimes a Comet Flashes
Into View That Exceeds
Venus in Brilliancy.

midable array Of first magni-
tude stars and planets for our
enjoyment, but the queen Of them all
is Venus. She outshines Jupiter and
Saturn. the giant planets and Sirius.
the most brilliant Of all the stars.
Venus is the brightest Of an the
heavenly bodies. with the exception.
OF course. Of the sun and moon
Sometimes a comet flashes up which
rivals or exceeds Venus in bright
ness, but these are only rare. though
welcome visitors. We have heard fl
said that objects cast noticeable
shadows IN the light Of Venus: we
must admit that we have never seen
such a shadow, though the truth Of
me staten elt IS not difficult to be-
lieve when one sees her briIlisncy-
these early nights Of January. Nat
urally. conditions for the observation
or sucn shadows must be particularly
favorable N the matter OF complete
absence or eN-raneous light sources.
thing which we know to be true is
that Al certain times Venus can be
easily seen IN the daytime That Is
when the planet is at the part OF its
orbit which astronomers call great
est elousatiou.' {. p. when il appears
IN the heavens as FAR from the sun as
II can reach. For several weeks
about TINS time one may get a faint
view OF the planet even when the
sun IS well above the horizon.
comparatively few people know
that Venus shows phases very similar
70 those Of the moon. they can be
observed only with a telescope. for
the planets disk is not large enough
10 ne seen without optical aid. This
is particularly good time for the
owner Of even a small telescope to
study these phases. for on the 4th OF
January Venus will be at her briEht-
est and thereafter will decrease N
ortllianey as she grows in phase.
Differs From the Noon.
That is quite different from the
case Of the moon which grows in
orilliancy as the phase advances. But
the two cases are not strictly parallel
For the moon travels around the
earth and is practically always at the
same distance from us no matter
what the phase or relative position
OF SUM- moon and earth. Il is not
50 with Venus. which travels around
the sun and changes her distance
from the earth rapidly from 26.OO0.-
COO when nearest 70 US. to $50. 600 600
miles when on the other side OF the
sun from us When exactly between
us and the san the phase might be
called new Venus and the planet is
OF course entirely invisible to us
As Venus leaves this position. a mar
row crescent like that Of the young
moon becomes visible. The phase :
continues 20 grow and the brillisncy /
increases as Venus proceeds on her
Journey about the sun. and At great I
est elongation We have half Venus
But the distance has increased also /
and as brightness falls off rapidly /
with Increasing distance. the effect or I
a greater proportion Of the surface {
being illuminated is overcome. The
growing distance overbalances the {
growing phase Venus then presents .
the phase like that OF the moon +.
about five days old
More About SOInr EeIfpsea.
Since an eclipse OF the sun is pro-
iuced by the interference Of the
moons mass between us and the sun.
thus shutting off our view Of the
latter, II can take place only when
the moon is in the new phase Or
iiuarily the moon is absolutely in
visible at the time Of the astronomic (
new moon because OF the glare OF
The nearby sun. Unfortunately. there
Is not a solar eclipse every time that
We have the moon new. This would
be the case only If the three bodies.
sun. moon and earth always Kept in
he same plane as the latter two per
formed their orhital rotations As i
4 matter Of fact. the plane OF the
orbit OF the moon about the earth
makes small angle. about five de
Zrees, with the plane OF the earth's
orbit about the sun. The latter plane
$ called the ecliptic plane by astron- /
'mers and the intersection points OF |
he ecliptlc and the moons orbit are
he lunar nodes These two points
ire the only points Of the lunar orbit
Fhich lie in the sun-earth plane and
therefore IL is only when the moon is
Il cor very near one OF these points
hat il IS in the same plane with the
Jun and earth. So that an eclipse Of
he sun can and does occur only
when the moon, at the time OF new
noon. is at or near one Of its nodes
We must explain why II il necessary
q say AT or near" the nodes instead
4 at only.
Looking From Earth'H Center.
II the three bodies in question were
merely dots. geometrical points, in
tead or bodies OF fair size compared
ven to the distances which separate
hem. the eclipses could occur at the
,odes only However. II we imagine
ourselves. Tor the sake Of the Illus
ration. TO be looking out from the
enter Of the earth, at the time when !
he node is exactly between us and
he center of the sun. We shall see
hat there will be quite a large area
( sky within which the moon could
e situated and still cut off at least
ONE Of the suns surface from our
rev Now, an observer can be at
arth facing the sun instead Of on the
aufral line ou1u and eha-aFo-o eFe 1 e