The Hickman courier. [volume] (Hickman, Ky.) 1859-current, 1877-08-24
rHe OPPOSITION or u.Ins.

Astronomers are DOW waiting with F.
great interest for q phenomenon which /
is.to occur iu a few weeks, and IS to be
observed with the utmost care and
asslduity, and with all the appliances at /
stfe disposal OF science. On September . (
10 planet Mars win be in opposition
That is, he win be at that point Of the /
~ which is just opposite the sun, so
L. be viii rise at sunset, and come to /
- sa.es ia1 At midO.ght@ sinss both
Tslie piarIo~ and earth sweep in orbits
around the suh,it follows also that at that
time they make Heir nearest approach
to each ether and le,planet is then
most favorably situated for observation
and examination. In theearlv autumn
Mars will be by far the mosJ-on,picuous
object in the eastern sky. blaznr with a
red fire hardly inie. ior 10 the bnlhtness
Of Venus, which by that time will begin
to adorn the western twilight, and quite
outshining Jupiter. Saturn, close by
Mars, will seem comparatively of no
account.
Oppcsitions Of Mars are rot specially
rare. They occur once in about two
years and fifty days, and IL the orbits Of
this planet and the earth were perfect
circles the circumstances Of all opposi-
tions would be essentially alike, and 10
peculiar interest would attach TO one
rather than another. But this is by no
means the case; the orbits are not quite
circular. The earth, about the first of
July. IS nearly 100000 miles farther
/ from the sun than at new years; and in
/ the case Of Mars the difference between
/ It's greatest and lea-t distance from the
sun is larger yet, amounting to almost
/ 28. 900 600 miles. The average distance
/ between Mars and the earth at the mo-
ment of opposition Is about $1,000, 900
miles if, however the opposition hap
/ pens when the planet is a- far from the
sun as possible, and the earth as near the
/ sun as it can be, they viii be separated
by a space Of 10000 miles; and If, on
the contrary, the event occurs when the
conditions are reversed, the distance
/ between them viii be only thirty-four
million, and the opportunity for obser-
walton viii be exceptionally favorable.
/ These close oppositions are rare, The
motions Of the planet and the earth
being so related that they recur only at
intervals Of seventy-nine years, though
some of the intermediate oppositions,
separated by periods of fifteen and sew
te7teen gears, are not very greatly infe.
rio-. The opposition Of next September
will be one of The best possible, both
earth and planet being in the most fav-
cradle positions, and the distance be-
tween them less than at any time since
the summer Of 179S. The observations
to be made are Of two classes-one in
tended 20 determine the distance, posi-
ton and motions of the planet; the
other relating to its magnitude, form,
rotation, suriace-markings and physical
constitution.
Bearing in mind that the proportions
Of the planetary system are easily ascer-
tanned and now very accurately known,
it is Of course evident that the precise
determination in miles Of any single dis
tance between any two planets viii fix
the dimensions Of the whole system,
and, so TO speak, put "a scale of miles
upon our chart Of the uuiverse. Obser-
vations of the opposition of Mars are
therefore available for the same purpose
as those of a transit Of Venus, and some
astronomers consider them capable Of
giving a result hardly, If at all, inferior
in certainty and precision. tits for this
reason, chiefly, that the phenomenon is
looked forward to with so much interest.