 This is the aspect of the heavens viewed from latitude 40 north, about 0400 on a January night. Turning toward the north point of the horizon and looking up toward the zenith, you would find the north celestial pole here. These stars near the pole, called circumpolar stars, never set in this latitude as they move around the pole in these diurnal circles. In middle north latitudes, the group of stars most easily identified is that group called the Great Dipper. It is composed of these stars. In the bowl of the dipper we have dubbe, mirak, fechda, migrez, and in the handle, alioth, myzar, alcade, sometimes called menetmash. If we take a line through mirak and dubbe and extend it, we come to Polaris or the north star. Notice how near this star is to the north celestial pole, which we mark with a cross. It is because of this nearness that we can find latitude by Polaris, as the altitude of the elevated pole is equal to the latitude of the observer. Continuing this line through Polaris, we come to a star group called Cassiopeia, which resembles a W or M depending on whether it is low on the horizon or high in the sky. Kaaf is at this end, while Rukba is located here. Notice the relative positions of the Big Dipper and Cassiopeia. They are equidistant from the pole and lie directly opposite each other. In middle northern latitudes, both of these constellations are always above the horizon. A line through migrez to alioth leads to a distinctive group just east of Arcturus called the Northern Crown. The bright star third from the end nearest to Arcturus is Alfeca. Now let us return to the Big Dipper and follow a curving line through the handle of the Dipper and extend it until we reach Arcturus. And still further along this line, we come to Spica. Near Spica is a group of stars in this arrangement often called the Cutter's Main Soul because of the shape. If we take Arcturus and Spica as two corners of an equilateral triangle, then the third corner is Denebola. A line through Arcturus and Denebola will lead to Regulus. Regulus may also be identified by extending the line through the pointers of the Big Dipper in the direction opposite to Polaris. Note that Denebola is located at the middle of a curved line connecting Arcturus and Regulus. Note the triangle formed by Arcturus, Spica, and Antares. From Spica through Regulus, we come to the heavenly twins, Pollux and then Caster. A most prominent constellation rises above the eastern horizon. It can be identified by three small stars close together and in a straight line. About these stars, called the Belt of Orion, observe the rectangle formed by three bright stars and one smaller star. The first star to northeast is Betelgeuse. Then to the west of it is Bellatrix and south of Bellatrix is Regal. The small star is unnamed. The center star in the belt is Alnilam. Now take a line through the belt to the southeast and we arrive at a very bright star called Sirius. This is the brightest star in the sky. If a curved line is run to the north from Sirius, we come to Procyon. And if the line is continued, we come again to Caster and Pollux. Still continuing the curve, we arrive at Capella. If we go back to Sirius and pass a line from there to Bellatrix and extend it, we come to Aldebaran. This, with four other stars, forms a V. A line through Betelgeuse and Aldebaran will bring us near Hamel in the constellation Aries. Directly to the west is a group of stars arranged in a square and called the square of Pegasus. Of the stars in Pegasus, we are interested in Alpharats in the northeast and Marcab in the southwest. Several hours later, when this constellation is higher in the heavens, we run a line through one side of the square of Pegasus, which will point to Denabcatus and a line through the other side to Fomalow. If we follow a curved line to the west of Fomalow, we come to Altair, which can be checked by the two painter stars. One on either side, which with Altair, are called the Shaft of Altair. Continuing the curved line, we arrive at the conspicuously bright star, Vega, which is at the 90-degree angle of a triangle formed by Vega, Altair, and Denab, which is in the northern cross. Altair, Denab, and Marcab form an equilateral triangle. In southern latitudes, the most outstanding group of stars is the constellation called the Southern Cross. The bright star at the foot of the cross, nearest to the south pole, is Alpha Cruces or Acrux. Nearby, we have Beta Cruces, the eastern star, and then Gamma Cruces at the head of the cross. Delta Cruces is the western star. Near the cross, we find a pair of bright stars, the pointers, that point toward it. The one farthest from the cross is Rigelkentaurus. If a curved line is run from Acrux, we find on it three stars approximately equidistant. Acrux to Myopacidus to Canopus. Acornar, Myopacidus, and the second brightest star in the sky, Canopus, form a 30-60 triangle. Canopus is at the 90-degree angle. When the Southern Cross is low on the southwestern horizon, you will see that a right triangle is formed by Rigelkentaurus, Antares, and Peacock. Note the pronounced shape of the constellation Scorpio, of which Antares is the principal star. Peacock, Acornar, and Fomulo form an equilateral triangle. One of the important things to remember about the constellations is that in their constant apparent motion, they make one complete revolution about the Earth in the course of one day. Of course, only about half of this motion is visible, as the stars can be observed only at night. However, as they rise earlier and earlier each night, during the course of a year, they can, at one time or another, be seen in all positions in relation to the horizon. For example, in latitude 40 north, about December 21st, the differ would be in this position in the evening. By midnight, it would have moved to this position. Observe that it is to the right of Polaris, and the handle is pointing downward. Continuing its motion to the westward, it would be in this position by morning. About midnight, March 21st, the differ would be above Polaris near the zenith, and in an inverted position. Observe that Cassiopeia appears like the letter W. About midnight, June 21st, the differ is to the left of Polaris, with its handle pointing upward. About midnight, September 21st, we see the differ below Polaris and close to the horizon. Cassiopeia now appears like the letter M. Now observe the appearance of Orion about midnight in December. Beetlegoos is highest above the horizon, and Sirius is to the left. In spring, Orion would be setting about midnight, and only Beetlegoos would be above the horizon. In the fall, Sirius is below Orion, which is close to the horizon, and rising about midnight. From latitude 20 degrees south, we could see the southern constellations in any of these positions during the period of a year. A familiarity with the heavens will give any navigator a confidence that can never be attained by depending entirely upon the use of mechanical means for star identification.