THE NEW PLANETS. 207 



difficult to observe these planets even by the aid of telescopes, it seems proba- 

 ble there may be other fragments revolving round the sun too minute to be 

 discovered. 



If a planet were broken into fragments, whether by external collision or by 

 internal explosion, it is demonstrable that the fragments into which it would 

 be resolved would severally revolve round the sun as independent planets. 

 Their orbits would be all nearly at the same distance from the sun as the orbit 

 of the original planet. These orbits, however, would be likely to differ from 

 that of the original planet in some respects. It is consistent with mechanical 

 laws that these orbits should some of them be inclined at a considerable angle to 

 the general plane of the solar system. It is also probable that these orbits or 

 some of them, might be more eccentric in their elliptical character than the 

 planetary orbits generally are. Now we find on examining the orbits of the 

 four new planets, that they partake of these characters. They are inclined to 

 the ecliptic at angles so considerable that they are the only planets which tran- 

 scend the limits of the zodiac, and are thence called ultra-zodiacal planets. The 

 eccentricities of some of their orbits are three or four times greater than those 

 of the planets generally. 



It is also demonstrable that if a planet were broken by any cause the orbits of 

 its fragments which would form independent planets would all pass through a 

 common point. Now this is a character which is also found to attach to the 

 four new planets generally. 



These circumstances would themselves afford a presumption so strong in 

 support of the supposition that the new planets are in fact fragments of a sin- 

 gle planet that has been broken as to amount almost to a moral certainty 

 but they are not the only ones that favor this hypothesis. 



Appearances have been observed upon these planets which render it ex- 

 tremely probable if not certain that they are not like the other bodies of the sys- 

 tem globular but that they are irregular in their form, having corners and angu- 

 lar extremities. This fact has been indicated by the sudden diminution of 

 their light when the angular points pass the line of vision. 



It is remarkable that VESTA, which is the smallest of the four in its absolute 

 magnitude, appears, nevertheless, the most brilliant, having the lustre of a star 

 of the fifth or sixth magnitude. SCHROTER, for this reason, was led to the 

 supposition that VESTA was a self-luminous body. The three other planets, 

 which are greater in magnitude than Vesta, have the appearance, nevertheless, 

 of stars of the ninth and tenth magnitude. CERES would seem to be extremely 

 irregular in its shape, since its light is very variable ; sometimes it is reddish 

 and vivid, sometimes whitish and pale. 



The atmospheric circumstances attending these bodies are very remarkable. 

 CERES and PALLAS, especially, seem to be enveloped in very dense atmo- 

 spheres, which 'extend to a height from their surface from twelve to fifteen 

 times greater than ours. 



The light of Vesta is more intense and white than that of any other of the 

 new planets. It also differs from them in not being surrounded by any nebu- 

 losity. Schroter affirms that he saw it several times with the naked eye, a 

 circumstance which must have arisen from the brilliant light reflected from its 

 surface not being obscured by any nebulous envelope. 



The planet Juno subtends to the eye, when nearest to the earth, an angle 

 of three seconds. It is of a reddish color ; and Schroter discovered around it 

 an atmosphere which he considered to be more dense than any of the atmo- 

 spheres of the old planets. Remarkable and sudden changes were observed 

 in the light of this planet, which Schroter first attributed to atmospheric phe- 

 | nomena upon it, but which have been since ascribed to great irregularity in 

 I 



