ASTRONOMY OF THE HEAVENS FOR MARCH.

By Prof. M. B. GOFF.

THE SUN.

This month, on the 1st, we can obtain mean or clock time by making our clocks indicate 12:12⅓ p. m. when the sun crosses our meridian; on the 15th, by making our time pieces 12:09 p. m.; and on the 31st, by making them show 12:04 p. m. On the 1st, 15th, and 31st, the sun rises at 6:33, 6:11, and 5:44 a. m., and sets at 5:52, 6:07, and 6:24 p. m., respectively. And on the same dates, daybreak occurs at 4:58, 4:35, and 4:04 a. m., and end of evening twilight at 7:27, 7:43, and 8:03 p. m., respectively. On the 19th, at 36½ minutes after 11:00 p. m. the sun “crosses the line” (that is, on its journey northward, crosses the equator), and we are accustomed to say that it enters the sign Aries, and spring commences. During this month we have also one of the five eclipses of this year. This one occurs on the 27th, and on such a portion of the earth’s surface as to render it invisible to most of our readers, being confined to a region within 42° of the North Pole, and embracing the North Pole, North Sea, Baltic Sea, Gulf of Bothnia, and the Scandinavian Peninsula. In Washington mean time, it begins on the 27th at 10:20.4 a. m., in longitude 9° 28.2′ east, latitude 54° 11.5′ north; greatest eclipse occurs at 11:10.5 a. m., in longitude 7° 50.1′ west, latitude 72° 5′ north; and eclipse ends at six minutes after 12:00 p. m., in longitude 103° 54.3′ west, latitude 87° 12.8′ north. This eclipse will excite little or no interest among astronomers, since the shadow cast by the moon hides only a small portion (about ⅐) of the sun’s disc, and will not afford any opportunity for observing the sun’s corona and the colored prominences (seen till lately only in total eclipses) which have been a source of so much interest and speculation to the scientific world. It may, indeed, not be saying too much to assert that hereafter eclipses of the sun may be looked upon as something to exercise the mathematical ability of students, and not as a means of obtaining a knowledge of the physical properties of that body. For it has already been demonstrated that the colored prominences may be examined at any time when the sun can be seen; and it is believed that Mr. Huggins has accomplished the difficult feat of photographing the corona, so that it too may be scrutinized at leisure. The importance of this discovery can be approximately estimated when we remember that, as Mr. Proctor asserts, “adding together all the minutes of total solar eclipse during an entire century, we obtain a period of about eight days during which the corona can be observed.”

THE MOON

Offers nothing special this month, except as noted, its interference with the sun’s light. Her phases will occur in the following order: 1st quarter, on the 4th, at 8:25 a. m.; full moon on 11th, at 2:32 p. m.; last quarter on 19th, at 6:05 p. m., and new moon on 27th, at 12:39 p. m. In case we have failed to set our clock by the sun, we may do so by the moon, which will cross the meridian on the 1st, at 3:36 p. m.; on the 15th, at 2:37 a. m., and on the 31st, at 4:20 p. m. On the 16th, at 11:18 p. m., she will be furthest from the earth; on the 28th, at 8:18 p. m., nearest the earth; and on the 4th, farthest from the horizon; that is in latitude 41° 30′, the elevation is 67° 19′.

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.

Superior Planets.

Superior planets are those whose orbits are outside that of the earth, and which are as a consequence, farther from the sun than the earth is. So far as we now know, all the planets except Mercury and Venus, are in the class “superior.” The first of these going outwardly from the sun is called

MARS,

Whose bright ruddy face, growing smaller every day, as it gradually moves away from us and the sun, is still distinctly visible, being above the horizon from 2:19 p. m., on the 1st, to 5:11 a. m., on the 2nd; from 1:21 p. m., on the 15th, to 4:11 a. m., on the 16th; and from 12:30 p. m. on the 31st, to 3:12 a. m. on April 1st. During the month its diameter decreases from 13.2′ to 10″. Up to the 12th, its motion is retrograde 56′ 36.6″. From that date to the end of the month, its motion is 1° 59′ 6.3″ direct. On the 12th it is stationary; or, at least, appears so. On the 22nd, it reaches its farthest point from the sun. It had often been surmised that Mars had a satellite; but it was not until after the 11th of August, 1877, that this supposition gave place to certainty. On the night of the date mentioned, Professor Asaph Hall discovered, a little east of the planet, a small object, which proved on further investigation to be a small body making a revolution in about twenty-nine hours, or as afterward appeared, in thirty hours eighteen minutes. Soon after was seen still closer to Mars an object which proved to be another satellite making a revolution about its primary in seven hours and thirty-nine minutes. These satellites not only make their revolutions in the shortest time, but are the least known heavenly bodies; the diameter of the outer one being estimated by Professor Newcomb at from five to twenty miles, and that of the inner at from ten to forty miles, the entire surface being little if any larger than the “ranches” of some of our western “farmer,” or “cattle kings.”

Between Mars and Jupiter, there was in 1801 discovered a small planet to which was given the name Ceres; in 1802, another named Pallas; in 1804 another named Juno, and in 1807, another named Vesta. From 1807 to 1845, discovery in that region seemed to cease; but since 1845 not less than two hundred and twenty of these bodies have been found and named, and are now called by the general name

ASTEROIDS, OR PLANETOIDS.

Of these none, except perhaps occasionally Ceres and Vesta, can be seen by the unaided eye. This is on account of their small size, their diameters ranging from fifty to two hundred and twenty-eight miles. The theory respecting these bodies is that they are portions of a larger one that in some manner became disintegrated, and each part obeying the laws of gravitation, formed itself into a separate sphere.

JUPITER,

Like Mars, this month will decrease somewhat in brilliancy, his diameter diminishing in appearance from 41.6″ to 38″. On the 20th he will be stationary. Up to that date he will have a retrograde motion amounting to 34′ 5.85″; and from the 22nd to the end of the month a direct motion of 13′ 37.9″. On the 1st, he rises at 1:48 in the afternoon; sets next morning at 4:26; on the 15th, rises at 12:50 p. m., setting next morning at 3:50, and on the 31st rises at 11:48 a. m., setting at 2:58 a. m., April 1st. On the 7th, at 8:16 p. m., is 5° 54′ north of the moon.

SATURN,

Though still a prominent object in the evening in the west, is fast approaching a time when its beauties will be rendered invisible by a greater luminary. Only temporarily, however; for next year it will emerge and shine with increased splendor. For this month, on the 2nd, it sets at 12:38 a. m., and on the 15th, at 11:47 p. m.; and on the 31st, at 10:50 p. m. Its motion is direct, and amounts to 2° 16′ 58″. Diameter on 1st, 17.2″; on 31st, 16.4″. On 3rd, at 2:08 p. m., it will be 1° 42′ north of the moon; and on the 30th, at 11:57 p. m., 2° 4′ north of the moon.

URANUS,

On the 16th, places itself directly on the other side of the world from the sun; in other words is in “opposition” to, or 180° from, the sun. Its diameter remains constant during the month (3.8″). On the 1st, 15th, and 31st, it rises at 7:00, 6:02, and 5:38 p. m., respectively. It sets on the 2nd, 16th, and April 1st, at 7:14, 6:18, and 5:14 a. m., respectively.

NEPTUNE

Will be evening star during the month, setting at the following times: On the 1st, at 11:22 p. m.; on the 15th, at 10:29 p. m.; and on the 31st, at 9:28 p. m. Its motion is direct, and about 45′. Its diameter, 2.6″. On the 2nd, at 12:30 p. m., 27′ north of moon; on the 29th, at 9:06 p. m., 38′ north of moon, making, as does also Saturn, two conjunctions with the moon in one month. On the 27th, about 9 p. m., it will be in conjunction with and 3° 34′ south of Venus.