Inferior Planets.
Inferior planets are those whose orbits are inside that of the earth. The first, whose mean distance from the sun may be put down as thirty-five millions of miles, is called
MERCURY.
It has one peculiarity; it twinkles like a star. In this respect it differs from all the other planets. Its nearness to the sun has led some astronomers to believe that the temperature is very uneven, that “every six weeks on an average there is a change of temperature nearly equal to the difference between frozen quicksilver and melted lead.” But later discoveries indicate that temperature dependent on the sun’s rays is influenced much more by the media through which the rays pass, or by which they are absorbed, than the proximity of the sun; and hence Professor Langley argues that Mercury might be a globe on which people like ourselves could have the proper degree of heat to sustain life. Our calendar for Mercury for this month is as follows: On the 1st, it rises at 5:50 a. m.; on 15th, at 5:54 a. m.; and on 31st, at 5:57 a. m. On the same dates it sets as follows: 3:52, 4:52 and 6:25 p. m. On the 30th it will be in superior conjunction with the sun, that is, in a line with the sun and earth, but having the sun between it and the earth. Up to this last date it will be morning star; after that, evening star. On the 26th, at 9:11 p. m., it will be 3° 25′ south of the moon. The only other inferior planet with which we are acquainted is called Venus.
VENUS
Will increase in brilliancy every day this month; but will not shine its brightest till about the third of June. Its time for setting will be as follows: On the 1st, 8:58 p. m.; on the 15th, at 9:28 p. m.; and on the 31st, at 10:03 p. m. Its motion will be direct, and amount to 34° 34′ 37.35″. Its diameter will increase from 14.6″ at the beginning of the month to 17.8″ on the 31st. On the 27th, at 9 p. m., it will be in conjunction with and 3° 34′ north of Neptune.