by Alien Wootton - , Throughout history astronomy has had an important place in regulating people’s lives. Three great. repeating events have done this: the rising of the Sun, the lunar cycle of phases, and the movement of the Earth about the Sun. These movements deter- mined our day, month, and year, and it is from them that our Gregorian calendar evolved. _ — - It would be very convenient if the number of times the Earth rotated on its axis.during a-year fit evenly into the length of the year, the time it-takes the Earth to revolve about the Sun. It would be even better if the length of time for the Moon’s: phases - also fitted evenly into’ the year. ‘Unfortunately, neither. situation — occurs. This presents a problem, because if a particular time on a particular day begins a year, the next year cannot start at that | — same time — for the Earth there are 365 and \Y days, and that extra % means that the second year should start six hours later , than the first, and the third year should be another six hours -after that. — - ae os 7:30 p.m. Any interested people are most welcome... “So you see, if you celebrate the New Year at midnight on Have a great time celebrating the New Year on Julian date 2... - December 31, you'may'be off by quite a few hours. This year, if 447 891.5. - - eo _ you see someone welcoming 1990 at 12 noon January 1, it is very _ a appropriate to join in; this is the time when the Earth will be night. ~ ; ‘ [still hope to see Vers before it disappears in the evening you should see a very nice crescent Venus: Look for this bright... - - planet near the southwesterit horizonat sunset. By mid-month — Venus will be too close to.the ‘Sun to be seen, however. - Mars will be visible slightly south of east in the morning sky. At suntise it will be about 15 degrees above the horizon. ° riear the Terrace Public Library after 8 p.m. on any.clear Tues- day night. Please feel welcome to come and take a look through this telescope. The next meeting of the Society will be held in the meeting room of the Terrace Public Library on January 23rd at. ~ poe _glow of the Sun.’ If you get'a chance to look at it with binoculars - . .The Terrace Astronomical Society will have a telescope set up y |. change our clocks the re- | quired one second the next time. we hear. the CBC: time J ‘| short tones, followed by the. of 1989 actually contained 61 . seconds. en stight slowing of the earth’s: sion timing, people iike. | navigational technicians. The | rest of us can confidently -signal: ‘“‘Af the sound of the long tone, the time will This phenomenon occurs |° } three or four times évery:two, | years, to compensate forthe I. rotation due to the changes. ° in the tides. The only people [-' directly affected by. this 7. ‘change are those using preci-: |. -be...”? Happy New Year! - back at an arbitrary starting point for another journey around the Sun. a - January 1 wasn’t always the starting point for the new year. This date was standardized -with the Gregorian calendar that is now used in most parts of the world. This calendar is based on _ the revolution of the Earth about the Sun; it is a solar calendar. While it is convenient to use a solar calendar, it is not necessary to do so. A calendar can be based on counting days, or much more.commonly, on counting lunar cycles. For example, the calendar used in Moslem countries is a lunar calendar that is not reset to-the solar year. As a result, the twelve months of this — calendar change the position at which they occur from one solar year to the next. Our calendar, the Gregorian calendar, was introduced to Roman Catholic countires in 1582 by Pope Gregory XIII. It superceded the Julian calendar that was developed by the Egyp- tian astronomer Sosigenes and intorduced by Julius Caesar. The two calendars are very similar, the difference being that the Gregorian calendar makes an allowance for the fact that the solar year is very close to, but not exactly 3654 days long, whereas the Julian calendar uses a year of exactly 36414 days. In practice, the difference between the two calendars is that the -Julian calendar specifies a leap year every four years while the Gregorian calendar has one every four years except for century ending years that are not divisible by 400. Thus 1800, 1900, and 2100 are lot leap years but the year 2000 is. Leap years occur in those years that are evenly divisible by four; 1992 is the next of these longer years. If the Julian and Gregorian calendars are compared for a few years there is very little difference between them. Over a long period of time, however, the differences become quite large. As a result, when Pope Gregory XIII introduced this calendar in 1582 the date had to be moved ahead 10 days to account for over 1,000 years of accumulated differences between a date and the Sun’s position on that date. . - When Pope Gregory introduced the calendar, Protestant coun- tries would have nothing to do with it. By the time England adopted it there was-an 11-day difference between the two calen- dars, so an overnight change from September 3 to September 14 occurred with the Gregorian calendar’s introduction to England in 1752. . Differences in calendars and the times of their introduction make it difficult for astronomers because they are frequently con- ' cerned with accurate dates of events and the times between them. For this reason, astronomers often use a calendar that is based on counting days. This system, called the Julian date, (named after Julius Caesar) was invented in 1583 by the French scholar Joseph Justus Scaliger. On the basis of long and relatively ar- bitrary calculations he chose January 1, 4713 B.C. as day 1 and it > is from this that the Julian date is counted. To avoid the difficul- - ty of a change of day in the middle of the night when an _ astronomer may be looking at stars, the Julian date changes at ‘noon. On this basis, at noon on January 1990 it will be Julian date 2.447 892. Our new year will begin at Julian date 2 447 891.5. - Until the development of modern clocks the Earth’s rotation _ -- and revolution provided the most precise clock available. With — _modern clocks, however, it has been found that the Earth’s rota- ~~ ‘tion changes slightly and, as a result, small adjustments must be _. made to the length of a year to compensate for these small dif-"" ferences. An article next to this one describes this year’s adjust- ment and the reasons for it. | : a pany bapa avill be-easity visible this: month (if the weather — during the annual Christmas CounterAttack campaign. . This scene was a familiar one for Terrace motorists during the past month (although the - sunshine was'a-aré occurrence). The local RCMP detachment kept-a close eye on drivers & finally co-operates). Jupiter will be well placed to view all night _ Did. you ‘know. that. you. f- _probably all heralded in-1990 |. _J.one second too-early? The | last minute of the last hour. ’ " et | | i .