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THE PLANET MARS.

view of the telescope. Phobos is therefore, in all probability,rather larger than Deimos .

We cannot but feel that there is altogether something verystrange about these little members of the Sun’s family. It ismost likely that some of our great landowners would hardlyfind sufficient room for such an estate as they occupy uponthe Earth, either upon Deimos or Phobos . They seem tobear somewhat the same relation as regards size to the restof the satellites, that the minor planets revolving outside theorbit of Mars bear to the other planets. Nor can we but bestruck with the fact, that we meet with them upon the confinesof the very same region in which the minor planets circulate.And, although they may have long belonged to Mars , and haveonly been so recently discovered, owing to the previous wantof sufficient telescopic power, we may, perhaps, be allowed tosuggest, that it is just possible, that these two satellites maybe two of the minor planets, to which Mars may have passedso near that it has picked them up and attached them to itself.

We are of course aware, in making this suggestion, how veryunlikely it is that a comet, or a meteorite, should at any timepass so close to a planet, and under such conditions as to itsvelocity and direction of motion, that its orbit should not only beperturbed (or, it may be, very greatly changed, as has happenedin the case of certain comets which have passed near to Jupiter or to Saturn ), but that it should actually become a satellite ofthe planet, and remain permanently attached to it. But thisdoes not seem to be quite so unlikely in the case of Mars anda minor planet, inasmuch as it will. be shown in our nextlecture, that we know at the present time of at least one minorplanet which, in the nearest portion of its orbit to the Sun,comes about five million miles nearer than the maximum dis-tance of Mars . Such an one, if its orbit were, only moderatelyoval, might therefore, at any given time, be moving nearly inthe same path and with the same speed as the planet itself,and thenceforth remain under its permanent control.

The small size of these bodies is not, however, their mostremarkable feature. Their nearness to the planet’s surface, andthe rapidity of their motions round it, are still more curious.