LOST COMETS

Evening Post, Volume CXII, Issue 57, 4 September 1926, Page 20

LOST COMETS

WHIRLING THROUGH OUTER SPACE.

It ii a strange fact that comets ue sometimes lost, writes J. A. Lloyd, F.K.A.S., in the "Daily Mail." The latest instance is Ensor's Comet. This was discovered in 1925 and was expected to be a prominent object in the northern heavens early in 1826. It seems, however, to have disappeared. A well-known which went astray is Biela's ,; Comet, discovered in 1826. Its path was calculated by the mathematicians and it was found to have a period of 6}. years. .It was seen on its next return to the sun in 1832, missed in 1839, and seen again in 1846, when it seemed at first to be quite normal. But after,a while it broke in two, the two' half-comets gradually separating from cash other. The two parts were again seen in 1852, but this time the distance between, them was much greater. The comet has never been seen since, but in. 1872, when the earth was crossing the path of the comet, a remarkable, shower of ehoot.ing stars came from the part of the heavens which would have been occupied by the comet if it had been visible. Yet another example is Lexell's Comet. This was discovered in 1770 by Messier. Its path was calculated by Lexell, who found that it should return every five years. But the comet was. never seen afterwards, although eagerly looked for. A comet discovered by Peters in 1846 was found to have a period of 13) years. It has never been seen since. Stephen's Comet, found in< 1867, and' calculated to return every 40 years, was not seen again. Do Vico's Comet, discovered in 1846, should have returned in 1921, but, in spite of the strictest watching, was not observed. Why should comets get losfc*f There are two good reasons. First, a comet is simply a swarm' of meteorites moving in an orbit round the sun. The tail consists of waste gases from the head. This meant that a comet is continually wasting away, and at every return must get smaller. Halley's Comet is not nearly so spectacular now as it was in ancient times. Secondly, a comet may pass near one of the giant planets,, Jupiter or Saturn, and so come under its gravitational influence.' The result is that the comet is thrown out of its course, and, instead of returning to the sun, passes off intospace, never to return. This ia probably what happened to Lexell's Comet.