Evening star., 1898-10-08
THE MINOR PLANETS.
Their Uses in Astronomy and a Re-
markabIe Discovery.
From the London Times.

| From the London Times.
| OF all the different departments of astro-
nc mical work minor planet" discovery hls
seemed by far the least interesting and
| profitable. There seemed no end to their
numbers-nore than 153 have been detected
within the last ten years-they are all 100
small for any markings to be observed on
! their surfaces or to afford fields for de-
| lightful specuations as to their climates
| and inhabitants; they are Just wandering
| boulders, as numerous as the pebbles on
the seashore, and with, for the most part,
scarcely more individuality to repay the
as tronomer for the toll of keeping a watch
| on their motions and of computing their
| olbits. So that 1t was with a decided feel
| ing Of satisfaction that most astronomers
| saw the first half of the present year go
| by without single fresh discovery.
The past two months, however, have
each brought a new capture the first dis
covered by NJ. Charlois of the Nice observa-
tory, on July 16, having special claims
to attention. But the second, discovered iy
| Herr Witt of the Urania observatory. Ber-
| lin. on August IA, seems to have so re-
markabe an orbit that astronomers Will
| think the labor spent on the discovery and
observation of the other 430 or so of these
| little bodies well bestowed. since 1t mas led
| to the discovery of this one.
The chief interest of minor planet as
tronomy has lain in the suitability of some
| of them for use in the determination Of
the fundamental unit of astronomy -he
distance of the earth from the sun. Some
| of them come sufficiently near the earth
every now and then for their distance to
| be determined with considerable precision
And as the relative distances of the var
1ous planets can easily be ascertained. 10
! know the distance accurately of one is to
know the distance Of ALL
But the minor planets as body lie
between the orbits of Jupiter and Mars
and only one or two ever come nearer to
the sun than the mean distance of Mars
The new planet, unlike all it's brethren, IL
the first attempts at the calculation of Its
orbit are to be received, has It's mean dis
tance from the sun within that of Mars
ard, travelling In a very eccentric orbit
will approach the earth, when it is at its
nearest approach to both earth and sun at
the same time, within 100000 miles It
In space after the moon herself but such
close oppositions will only occur about once
in thirty years. The time of revolution of
the new planet is 645 days.
Like the other pocket planets" 1t Is of
very small size, say twenty or twenty-five
miles in diameter; but on the occasion Of
very close opposition it will shine as a
sixth magnitude star, and therefore be Wis
ible to the naked eye. Even at its most
distant oppositions 1t will be Of the elev-
erth magnitude, five six times as bright
that Is, most Of the more recently dis
covered minor planets. This fact makes IL
covered earlier, and creates the hope that
other bodies nearer than Mars may be de-
tected. At any rate, 1t will revive the in
tGrest in the search for small celestial wan
derers, Of which 1t Is at present by far the
most useful and interesting.