ASTRONOMICAL NOTES FOR MARCH

Otago Daily Times, Issue 24236, 1 March 1940, Page 13

ASTRONOMICAL NOTES FOR MARCH

Specially written for the Otago Daily Times. The four bright planets are still visible in the evening sky, their order proceeding eastward from the sun being: Jupiter, Venus, Saturn, Mars. On March 8 Venus is in conjunction with Saturn, so that their order changes after this date. On March 1 the times at which they set are: 8.37 p.m., 8.47 p.m., 9.16 p.m. and 9.27 p.m. On March 31 Venus sets only 46 min'* utes earlier, and as sunset is much earlier then, it is evident that she is becoming more conspicuous in the evening sky. Her, elongation from the sun is nearly 41deg, not much less than the maximum. 453 deg, which she attains in April. Uranus is a little more than Ideg south of Mars on March 16, and 2ideg south of Venus on March 26. Neptune is in opposition to the sun on March 14, near the boundary of the constellations Leo and Virgo. The minor planet, Ceres, is also in opposition on March 11. but her position is well to the north of the ecliptic, in declination 23. north. R.A. 11 hours 19 minutes. She is considerably the largest of these planets, although not the brightest, Her diameter of 480 miles is enough to make the area of her surface about seven times as much as that of the whole of New Zealand. In comparison with this, Juno, the fourth in order of size, has a surface only about equal to that of the North Island. The new planets, which are reported now, are small objects detected on photographs of stars by their motion during the prolonged exposure, and their number is probably approaching 3000. The zone of the minor planets used to be described as between the orbits of Mars and Jupiter, but now there is at least one. named Hidalgo, which goes outward nearly as far as Saturn, and there are three, which come betwee Mars and the earth, named Eros, Albert and Alinda. Seven of them have almost the same mean distance as Jupiter, and have been given names taken from the Iliad —Achilles, Hector, Patroclus, Priamus. Nestor, Agamemnon and Diomedes. Four planets discovered in recent years cross the orbit of the earth; the names given to them are Amor, Apollo, Adonis and Hermes. The last of these was found on several photographs in October, 1937. when it passed within 485.000 miles of the earth, and its computed orbit now shows that it could come within 220,000 miles, less than the mean distance of the moon. Even st these short distances it is a faint object, and probably it measures less than one mile in diameter, so that it may be compared with the object which is reputed to have been the cause of a crater in Arizona, about a mile in diameter and 600 feet deep That has always been called a meteor so that it has been pointed out that we are approaching a parlous state, in which we have to definite a minor planet* as an object shining by reflected sunlight outside the earth’s atmosphere, and a meteor as an incandescent body within our atmosphere The constellations. Orion and Taurus. are now considerably to the west in the evenings, and. instead of them, we see the Twins due north about 9 o’clock. The two bright stars. Castor and Pollux, about 15 degrees above the horizon, make this constellation easily recognisable. To the right of them is the Crab, a collection of small stars; then the Lion, in which six of the brightest stars form a sickle. There seems to have been some confusion here: the constellation looks more like a sickle than a lion, and the next one to the east, the Virgin, is undeservedly supposed to represent a girl with a sickle in her hand. How the brightest star in the Lion received the name of Regulus is another mystery. This Roman general died at Carthage, and it was a natural death. That is contrary to the story we have all heard in the years of our youth, but the history books of the kind not supplied to schools inform us that the atrocities ascribed to the Carthaginians were what we of more civilised nations call “ propaganda.” On March 1 the sun rises at 6.12 a.m. and sets at 7.28 p.m., giving 13 hours 16 minutes of sunshine. On March 31 he rises at 6.22 am., and sets at 6.36 p.m., giving 11 hours 36 minutes of sunshine. Thus the length of the day decreases by .1 hour 40 minutes during this month. The equinox is on March 21. the time when the sun is on the equator being 6.25 a.m. The moon is at last quarter on March 1. and rises on that day at 11.40 p.m. She is at first quarter on March 17 and sets on that day at 11.42 p.m. Full moon occurs on March 24. and she rises at 6.47 p.m. on that day and sets at 8 6 a.m. on the morning of March 25. She is at last quarter again on March 31, and rises at 0.14 a.m. on the morning of April 1. On March 21 the moon occults a sixth magnitude star in Leo, the star being hidden at 11.12 p.m. On the morning of March 23 she occults a fifth, magnitude star in the same constellation, the star disappearing at 2.27 a.m.