Mars Weather.

Hokitika Guardian, 5 December 1922, Page 3

Mars Weather.

MORE VARIETY THAN SUPPOSED. LONDON, October 3. Professor W. H. Pickering, who has been ohseiving -Mars at Mandeville, Jamaica, c mti ihutes an article to Popular Astronomy asserting his belief Hint the londitions on the planet are by no means so arctic as some critics nave lately asserted. He concludes that even in the polar legions the temperature i isex we’l above freezing-point; this is shown by the rapid melting < f the white polar cap, and hv the dark hroail hand that then appears mound it. Some have suggested that the cap is not composed of snow, hut of frozen carbonic acid. This is held to be very unlikely, both from the difficulty in supposing that this gas could be so plentiful on Mars, and the fact that it requires a pressure of five atmospheres to liquefy it—the Martian atmosphere has certainly much less pressure. The temperature by <lay in the .Martinn tropics is put down ns about GOdeg. free from frost or snow at ' midday, though not in the morning or evening; a further argument is derived from the greenish appearance of- the dusky legions of the planet in the springtime, which terrestrial analogy suggests to be due to vegetation.

NKDIT frost everywhere. Professor Piekering further points o"t that the frequent presence of morning and evening mist may indicat" t' e prevalence of eloud at night. This would tend to mitigate the intensity of the frost that would otherwise prevail at night in all latitudes of tile planet. The Lowell Conservatory at Flagstaff Arizona, is continuing its work on Arm's. Mr K/C. Slipher gives a description illustrated by drawings and photographs, of a large white spot tliat appeared for a few days in niid.fulv at the southern end of the Margaritifer Sinus (Gulf if Pearls.) Tt appeared suddenly on July !Hh.. iis,a yel-lowish-white oblong, 800 miles by 400; the next day it was much larger hut fainter and was divided into three portions by dark bands. On July 12 on y on of three portions remained, and t.h.R ton soon disappeared; from its changes of position it was almost certainly dense cloud, not snow. ’lhe presence of this character at noon in the Martial tropics is rare, hut not unprecedented. A together the observations of the year support the view that there is j “more weather” on Mars than some have been disposed to allow.