RARE PHENOMENON

Wanganui Chronicle, Volume 72, Issue 199, 22 August 1929, Page 3

RARE PHENOMENON

APPEARANCE OF MOCK MOONS REFLECTION ON CLOUDS An interesting and very rare atmospheric phenomenon was visible in Auckland early on Saturday morning, when there appeared to be three moons in the sky. At the time the sky was covered with a light, misty cloud at a high altitude, through which the moon shono practically undimmed in brilliance. The moon w r as encircled by a pearlywhite halo about 23 degrees in dia- 1 meter. On the circumference of this halo, and level with the real moon, appeared two round patches of light, quite prominent to the eye, which resembled the light of a concealed moon shining through clouds, and they could have been explained by this reasoning had not the real moon itself been plainly visible. The phenomenon was first noticed at 2 a.m., the mock moons being sufficiently bright to excite attention, in spite of the brilliant street lights. On closer examination each false moon was found to possess a comet-like tail of less brilliance, pointing, in each case, directly away from the real moon. When the eye was shielded from the glare of the street lights it was possible to define the outlines of a third, and even fainter, mock moon, which was little brighter than jthe halo in which it was embedded.

No trace could be seen of any secondary arches to the main halo, and heavy clouds after 2.30 a.m. extinguished the strange spectacle. Mock moops, or paraselenae, aro most commonly observed in the polar regions, where they arc of fairly common occurrence, but it is only on very rare occasions that they are witnessed in such low latitudes as that of Auckland. They arc probably formed by reflections in clouds situated at great heights above the earth’s surface, known as ciros, in which gold crystals serve to break up the moon’s light. As an illustration of the rarity of the phenomenon in these latitudes it is of interest that a kindred phenomenon, mock suns, which was seen in Yugoslavia in February last, is the first recorded case visible there in 414 years. It is extremely unlikely that such a phenomenon has previously been seen in Auckland.