ASTRONOMICAL NOTES FOR NOVEMBER.

Taranaki Daily News, Volume L, Issue 61, 21 November 1907, Page 4

ASTRONOMICAL NOTES FOR NOVEMBER.

o Rev. 1\ W. Fairclough, F.R.A.S., writing iu the Cbristchurch Press, says:— Venus is an evening star, setting scon after sun. Mars, owing to increasing distance, is losing much of the glory he displayed a few months ago. He sets in the small hours. Saturn is due north about 8 o'clock. Jupiter rises about 10 in the evening. Mercury will make a transit across the sun's face on the 1-lth inst., but the eu-nt will not be visible in New Zealand, as it will take place between 10 p.m. and 2 a.m. by our time. The planet will be on the sun about three hours. No great scientific importance i; attached to this phenomenon. Mercury Bay, in Auckland province, is so called from the fact that Captain Cook went in there to observe a transit of Mercury. The comet has now deserted us. It H catalogued by astronomers as "Daniel's Comet, 1907 d" —being the fourth cf the year. It was at its maximum brightness in August. The dimeter of the nucleus was 105,000 miles, and the greatest length of tail ' .ias 7,500,000 miles. Nature for August 29 contains three of Lowell's photographs of Mars, showing "canals," including one or two double ones. Lowell has been able 11 discover over fifty canals in the negative. The photos are about an inch in diameter. Writing on the recent opposition of Mars, Lowell describes the north polar snow cap as being reduced to eight degrees in width by the heat of the summer, while the winter rap in the south extended to eighty degrees, coining down to latitude forty—as it were to New York. As the northern winter approached, the north cap suddenly extended over a wide area, as it were by a night's frost or snow. It began to spread in 1903 and 1905 in a similar manner after the summer was past. The first fall melted again in a few days, and was succeeded by another and more permanent coating. These observations lei Lowell to investigate mathematically what is called the problem of daily insolation on a planet. He found the theory to agree with the observed facts. The planet has an atmosphere sufficient to retard the deposition of frost by 19 days. The poles of Mars are hotter in summer than ours, though the mean temperature of the planet 48F., is about 12 degrees below that of the earth. Much fog and cloud htve been observed on Mars this y^r.r. Lowell describes the canals as developing again this year in the same manner as he has described in his book on Mars. As the spring advanced in the South the snow cap was reduced and the canals appeared first near the snow and then extended themselves northwards, as though the flowing of the water from the melting snow, by being spread over wide belts, produced vegetation, and so made the belts or 'canals' visible. At the same time the canals, in the north, where the summer was over, had almost entirely faded out of sight. This he would explain as meaning that the crops were ripe and harvested, so that the dark color was gone. Lowell firmly believes that there are intelligent beings at work on Mars.

The Yerkes Observatory reports the discovery of a valuable star that runs through its cycle of change in the extraordinarily short period of ten hours and 37 minutes. In 1848 Lord Rosse, with his great 6ft reflecting telescope, observed the "Owl Nebula." This object presents a round disc with two holes, or dark spots, like the eyes of an owl. Lord Rosse, in his drawing, placed a star in the centre of each eye, which certainly improved them. This year the great Yerkes 40-inch refractor has been turned on to this nebula and has found that the stars are not in the eyes at all, but arc as though they had moved to the right, one ou to the bridge of tht nose and the other on to the temple. This raises a question, "Has the nebula rotated, or did Lord Rosse's fancy lead him to misplace the stars?" A number of years must elapse before astronomers will feel certain which is the correct answer.

"Hillgrove" sends us a welcome question: "You state that Arcturus has only move! a certain space since the time of Job. How can astronomers speak of thj position of a star at that time?" Arcturus is so distant that it has hitherto defied all efforts to arrive at a reliable parallax. Yet this star moves on the celestial sphere about two seconds of arc per annum. There are 3600 seconds in a degree. The 'ill moon is half a degree across, or IHOO seconds. In 900 years Arcturus would, therefore, shift his place by the diameter of the moon. In twenty-seven centuries he would move three diameters of the moon, or a distance equal to the length of Orion's Belt, marked by the three well-known stars. The date of Job is, of course, not very certain, but 27 centuries would probably more than reach him. If this be granted, then it is clear that Arcturus cannot have shifted by more than three diameters of the moon since Job's day. The fact that the Patriarch mentions the star accounts for his being cited in nearly all discussions of the star to lend emphasis to a sublime fact. Arcturus is believed to be rushing through Space at about 300 miles in every second of time; yet so appallingly distant is he that, could Job revisit the glimpses of the moon he would probably not notice that the star had shifted his position. Mr Gore mentions that in 32,000 years Arcturus will have left Bootes and have entered the constellation of the Virgin!