The Saint Paul globe. (St. Paul, Minn.) 1896-1905, 1903-10-25
THE PLANETOfDS
APopuIar Study of Heavenly BOdles-By Ps o. T. Denny.


Before passing on to the study of
Venus and Mercury, 1t might be well
/ to pause long enough to give a passing
notice to the asteroids; or, as much
prefer to call them, the planetoidS.
| Heretofore, our study of the planets
| has not been regular and methodical, so
| far as relative size or distance is con-
| cerned; but we have taken them as
1 they now appear In the evening sky.
! in passing from east to west. Venus
which would naturally come next, has
/ passed from the evening to the morning
| sky, where we will leave her till we
| take view of that strange, new group
of the solar family, known as the PLAN
etoids.
Perhaps our youngest readers will
recall that all the planets revolye round
| own distance. 1t was discovered by
Kepler that there is regular law gov
erning the time of the planets revolu-
| ton and it's its distance from the sun.
This law is as follows: For any two
planets, the squares of their times or
revolution round the sun are proper
! tional to the cubes of their distances
| from the sun. IT, then, we know the
distance of one planet, and the times
of revolution of all of them, we can
readily calculate all their distances.
This is one of the most wonderful laws
of all science, and to many minds II
argues the existence of a wonderful
harmony and divine order among
! the celestial bodies. But another law
was announced later, which is known
as BODIES law, because he brought 1t
into prominent notice. 1t is as follows:
Take the series of numbers, 0, 8, 6, IL,
| "a, 48, SO, 1872, etc, in which each num-
Der except the first is doubled to get
the next; and adding to each we have
I A -
numbers represent approximately the
relative distances of the planets from
the sun, in which Mercury is 4, Venus
Z, Earth 10, Mars Is, Jupiter SO, and
Saturn 100. But when the law was
announced there was no known planet
corresponding to 2S, and none to 1876.
The imaginative Kepler boldly affirm
ed that there must be a planet for 20,
and many others shared his opinion.
When, in 1881, the planet Uranus was
discovered closely conforming to 1876,
1t greatly strengthened the opinion that
there must still be an undiscovered
body for %. From that time to the
present careful and persistent search
has been prosecuted, which has resulted
In discoVering-not one large planet,
but multitude of small ones, which we
call planetoids. Their distances, of
course, vary but they may be said, in
the aggregate, to fill the vacant place at
20, and thus tend to confirm the law.
But when, in 1916, by one of the most
astonishing feats of mathematical skill,
the planet Neptune was discovered, it
was found that it did not correspond
to the next number in the series, even
approximately. And so the question
still remains rs BODIES law really
law, or only happy coincidence"
AS result, then, we have a. large
family of small planets, or planetoids,
TOO small to compare with the major
planets, whose orbits lie between Jupi-s
ter and Mars, and whose number is al
ready nearly five hundred not a year
passing in which others are not found,
and still there's more to follow Lee
Verr1er, the great discoverer of Neptune.
said there may be 10000 of them, most
or them being very minute
When these bodies were first discov-
ered-so many where they had expected
one-it was conjectured that the small
bodies were simply fragments of one
large planet, which had been shattered
by some tremendous catastrophe some
terrific explosion, which sent the frag-
ments flying in their individual orbits
round the sun. But no single explo-
sion could account for the present or
bits, unless We may suppose that the
attraction of Jupiter, perhaps. has
changed their original orbits to their
present forms; for it is we'll known
that after the explosion, and after each
fragment had completed it's Journey
round the sun, it would return to the
original point of the explosion. Now,
no such common point is found in
their orbits, and it is necessary to sup /
pose other explosions occurring in the
fragments themselves. But all this
seems quite improbable and it is far
more reasonable to account for them nv
the nebular hypothesis, hint of which
we have in the rings of Saturn. In
THIS case, however, the ring of matter
Wmch should have formed one planet.
was broken up by some external inf1u-
ence (most likely Jupiter's attraction.
and separated into many rings. each Of
winch gave rise to a planetoid or to
several But nothing can be said to he
oefnitely known concerning their orr
gin.
THESE little bodies are so small and
at Such large distances from us that it
is difficult to learn much of their phvs-
1cal features. They shine like faint
stars as seen through a telescope.
though one or two Of them NAV he
seen by good eyes when thew are at a
favorable opposition. Two or three of
the largest may have a diameter of
several hundred miles, but the greater
NUMBER OF them are tiny indeed,
perhaps not more than five to twenty
miles In diameter. How insignificant
are such bodies, compared to our grand
old earth. which, In turn, Is only a mig
my beside great Jupiter. But these
vast differences present to us the won
derful variety In form and size, In
structure and action, in which nature
seems 10 delight. Can we picture to
ourselves a little world-say ten miles
IN d1ameter-revolving round the sun
and at the same time rotating on its
little axis? Such is one (and doubtless
many of the planetoids. Why, a good
automoblle would easily go entirely
round 1t In three hours. if there are
the way. And what tiny seas, thew
must be, If they are proportionate to
ours! Perhaps they are not over fiftv
rect deep in the deepest places, and in
most places man could easily wade
them. mountain on this little world
TO correspond with Mount Mckinley. in