As intimated last month, continues to be an evening star, making every evening an increasingly handsome display in the western heavens, her diameter growing from 12.8″ on the 1st to 14.6″ on the 29th. Her motion, which is from west to east, amounts during the month to 31° 51′ 37″ of arc. Her time of setting, on the 1st, 15th and 29th, is as follows: 7:54, 8:26 and 8:57 p. m., respectively. On the 29th, at 10:07 a. m., she will be in conjunction with, and 32′ south of the moon.
MARS
Will present nothing particularly new. His retrograde motion still continuing, he will rise earlier each evening, and, of course, set earlier the following morning. Thus, on the 1st, he rises at 4:51 p. m.; on the 15th, at 3:35 p. m.; and on the 29th, at 2:23 p. m. He sets on the mornings immediately following these dates at 7:29, 6:23 and 5:15; or, on the first date about twenty minutes after, and on the latter date about one hour and twenty minutes before sunrise; during the month taking his place as an evening star. His motion amounts to 9° 7′ 11″ of arc, and as he is going farther from the earth, his diameter grows smaller, being 15″ on the first, and only 13.2″ on the last of the month. On the 10th, at 4:40 a. m., he is 9° 43′ north of the moon, and a little east of the nebula Præsepe in Cancer.
JUPITER
Will be evening star throughout the month, and continue his retrograde motion from a point about twenty minutes west of Præsepe on the 1st, to 7 hours 48 minutes 35 seconds right ascension on the 29th. He will rise on the 1st at 3:56; on the 15th at 2:53; and on the 29th at 1:52 p. m., and will set on the 2d at 6:30; on the 16th at 5:29; and on March 1st at 4:30 a. m. On the 9th, at 5:39 a. m., he will be 5° 45′ north of the moon. Of the four satellites, or moons, revolving around Jupiter, three are so near as to be eclipsed by him at each revolution. Roemer, a Danish astronomer, observed, however, that when the earth and Jupiter were on opposite sides of the sun, these eclipses occurred, as he estimated, about twenty-two minutes later than the time predicted by the tables. As the earth in this position was some one hundred and eighty-six millions of miles farther away from Jupiter than when Jupiter and the earth were on the same side of the sun, the discovery was made that the discrepancy in time was occasioned by the fact that light must have time to travel; and later and more accurate investigations afford us the truth that it takes light sixteen minutes and forty seconds to cross the earth’s orbit, or eight minutes and twenty seconds to come from the sun to the earth; and hence, that it travels about 180,000 miles per second. These eclipses occur frequently every month, and can be observed with telescopes of quite moderate power.
SATURN.
This planet will be evening star throughout the month, setting as follows: On the 2d, at 2:28 a. m.; on the 16th, at 1:33 a. m.; and on the 29th, at 12:41 a. m. Its direct motion amounts to 41′ 32.1″ of arc. On the 3d, at 9 a. m., it is stationary. On the 5th, at 7:34 a. m., 1° 18′ north of the moon. On the 22d, at noon, it is “quartile,” being 90° east of the sun. It can be found near the Hyades, a little north, at any time this month. Its diameter decreases from 18″ on the 1st, to 17.2″ on the 29th.
URANUS
Makes a retrograde motion of 55′ 47.1″, and retains the same diameter, namely, 3.8″. It will be morning star, rising however, early enough to be viewed in the evening. For example, on the 1st, at 9:00 p. m.; on the 15th, at 8:02 p. m.; and on the 29th, at 7:04 p. m. It will set as follows: On the 2d, at 9:10 a. m.; on the 16th, at 8:14 a. m.; and on the 29th, at 7:18 a. m. On the 13th, at 7:44 p. m., it will be 3° 18′ north of the moon. On the 29th can be found nearly on a line between Beta and Eta in the constellation Virgo, and from Beta about one-third of the distance between these two stars.