The Birmingham age-herald., 1923-02-25
THE STARRY SKIES IN MARCH
By PROFESSOR BARTON


 By PROFESSOR BARTON
 Of the University of Pennsylvania
 The month of March comprises the first of the two eclipse periods ot the year. There is an eclipse of both the moon and the sun this month. The first interests us more because we can observe, it. This Is only d partial eclipse of the moon. The fast eclipse of the moon was on October l6. 1921. Figure 9 represents the condition of the eclipse. As the sun is larger than the earth the sun shining on the earth causes it to cast great conieal shadow in the opposite direction away from the sun. When the moon enters this shadow, the sun's light no longer falls upon 1t and it becomes nearly invisible. The base of the cone at the earth has a diameter equal to that of the earth nearly 5000 miles. At the distance of the moon it Is somewhat smaller-about 6.100 In diameter. It is this cross section of the cone at the distance of the moon which is represented in Figure and named the earth's shadow. In this case the moon does not cross the shadow squarely and is never entirely within the shadow. At the maximum eclipse in Position 2 a little over a third of the moons diameter is in the shadow.
 AS the earth moves about the sun the shadow moves slowly. The moon moves about 12 times as fast as the shadow and overtakes it.
 It first encroaches on the shadow as shown in Position l at S:2s p. m. March 3. eastern standard time. The ha c1, ]nxu nd fa maximum eclipse in Position 3 at 11,S2. The moon has it's last contact with the shadow in Position at 11:36. The full moon occurs at 10:24. The middle of an eclipse of the moon must always be very near the in- stant of full moon. The earth's at mosphere refracts some light into the shadow, so that the part of the moon within the shadow can be faintiy seen. Figure 2 shows the shadow, but of course the shadow cannot be seen in the sky
 The eclipse can be seen wherever the moon can be seen at the time 1t passes through the shadow. The whole of the eclipse can be seen from all parts of North America. It will not be seen in Asia and the Pacific ocean. There will be another very small partial eclipse of the moon in August and none visible here next year.
 Eclipse of the Sun.
 Two weeks after the eclipse of the moon the moon has moved half way round in its path around the earth and comes between the earth and the sun. The eclipse is an annular eclipse, which will not be visible here in any part. It occurs on March IT,. The eclipse will be seen. from the southern parts of South America and Africa only. There are no other eclipses until August 2s.
 0 o O
 The Planets.
 There are now no planets to be seen well in the early evening. Mars may be seen low in the west in the early evening. Its position at the beginning of the month cannot be shown on Figure 1, but the position at the end of the month is shown. The position of Neptune in Led is shown. This planet cannot be seen with the naked eye. Saturn Is just on the eastern border of the map. We shall now see 1t in the early eve ming for about six months. The rings are now more widely opened than for several years past. Venus may be seen in the east before sunrise. The sun crosses the equator March 21, io:29 a. m. This event marks the beginning of spring. I'll. stars. Q Q Q
 The Milky Way. now approaches the western horizon preceded by the bright winter cancellations and fol lowed by much fainter ones Tn fact, it is followed by a section Of the sky almost devoid of bright stars The star at A in Hydra is called AL phard, meaning "the solitary one" because of it's isolation from other bright stars, although it is by no means a conspicuous star. z It is not at all comparable in brightness with it's neighbors. Sirus at B, Procyon at c, or Regulus at D. At E and F are the twins Castor and Poilux, the former the most conspicuous of double stars and one within the sep arating power of small telescopes. Midway between these twins and Regulus at the bottom of the handle of the sickle in Leo lies the con stellation. Cancer, the name of which is familiar to many, although the constellation is unknown to many who are familiar with; other constei- lations. It's brightest star is of the fourth magnitude. The conStelation owes it's importance chiefly to It's location in the Zodiac, the track in which the sun, moon and planets move. At the time when our pres ent system of naming the signs of the Zodiac was introduced the con- stellation Cancer was near the point at which the sun is farthest north of the Equator. This point at which the. sun changes from a northward to southward motion is called the solstice. or tropic Burning point.) Because of the procession of the equi- noxes the solstice is no longer in the constellation Cancer, but Is in the sign Cancer of the Zodiac, which takes it's name from the constellation. The solstice is now at c, Figure l.
 The name Tropic of Cancer is now