2012 Astronomical Calendar

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Sky Mapabout 10 p.m. at the 5th of the month

or 9 p.m. at the 20th

For latitude 40 northand sidereal time

5h

Jan. map serves forFeb. 78 p.m.Mar. 56

Sep. 56 a.m.Oct. 34Nov. 12Dec. 1112 p.m.

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Orion raises shield and club todefend himself.

The Bull: triangular face (Hyades)and two long horns.

Aldebaran a red glaring eye.Pleiades in the hump of the Bullsshoulder.

El Nath (Arabic the butting),point of the upper horn, former-ly belonged to Auriga as well.

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Below Orions feet: the Hare(Lepus), then the Dove(Columba).

Big Dipper now stands like aquestion mark.

Western end of Leo like a reversequestion mark with Regulus thedot.

6 Astronomical Calendar 2012

JANUARY Januarius, month of the god Januswho faces both forward and backwardthrough the door

telescopic tour(coordinates of 2000)

17 41.9 +72 10 Draconis, double star0 42.7 +41 16 M31, Andromeda galaxy1 33.9 +30 39 M33, Triangulum galaxy2 03.9 +42 20 Andromedae, double star2 21.5 +57 08 Perseus double cluster2 29.0 +67 24 Cassiopeiae, triple star2 50.6 +55 53 Persei, double star3 47.5 +24 06 Pleiades4 59.6 14 47 R Leporis, Crimson Star

5 35.4 5 22 M42, Orion nebula5 38.7 2 35 Orionis, multiple star6 08.9 +24 21 M35 cluster6 32.4 +4 52 Rosette nebula7 34.6 +31 54 Castor, double star8 40.4 +19 41 Praesepe cluster9 55.6 +69 04 M81 galaxy

10 19.9 +19 51 Leonis, double star13 23.9 +54 55 Mizar, double star

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months.qxd 01/09/2011 07:49 Page 6

( 7 UT= 2 EST) Mercury 4.6 S. of Pluto (15 from Sun in morning sky).Conjunction in r.a. is 1.4 hours later.

(16 UT=11 EST) Venus 1.1 S.S.E. of Neptune (36 from Sun in evening sky);magnitudes 4.0 and 8.0. Conjunction in r.a. is 9 hours earlier.

14 SAT. This day is Jan. 1 in the Julian calendar, which was superseded by the presentGregorian calendar from 1582 (later in many countries). It is the first day of the Romanyear 2765 A.U.C. (ab urbe condita, from the city founded). Julian years wontdiverge by another day (starting on Jan. 15) until 2101. See Ast. Companion, CALEN-DARS.

( 1 UT=20 est) Moon 8.4 S.S.W. of Mars (121 from Sun in morning sky).______________________________________________________________________

16 Mon. ( 5 UT=24 est) Moon 2.2 S.W. of Spica (about 91 from Sun in morning sky).( 9:08 UT= 4:08 EST) Moon at last quarter.(17 UT=12 EST) Moon 6.1 S. of Saturn (about 86 from Sun in morning sky).(21 UT=16 EST) 11 Parthenope 2.0 S. of Pluto (about 18 from Sun in morning

sky). 17 Tue. (22 UT=17 EST) Moon at perigee. Distance 57.99 earth-radii. 18 Wed. ( 6 UT= 1 EST) Mercury at aphelion, 0.4667 a.u. from the Sun. 19 Thu. (12 UT= 7 EST) Moon 4.2 N. of Antares (49 from Sun in morning sky).

(18:30 UT=13:30 EST) Moon at ascending node (longitude 253.5).(21 UT=16 EST) Saturn at west quadrature.

20 Fri. ( 7 UT= 2 EST) Sun enters Capricornus, at longitude 299.62 on the eclip-tic. (Because of precession these constellation-boundary-crossing-points shift eastwardslightly along the ecliptic each year, i.e. their longitudes increase; so their datesbecome a few hours later.)

(16 UT=11 EST) Sun enters the astrological sign Aquarius, i.e. its longitude is300. But astronomically it has only just entered Capricornus. See Ast. Companion, PRE-CESSION.

21 SAT. (13 UT= 8 EST) Moon 1.8 S.S.E. of Pluto (about 22 from Sun in morning sky).(18 UT=13 EST) Moon 1.2 E.N.E. of 11 Parthenope (about 20 from Sun in

morning sky). See ASTEROIDS. The Moon again passes close on Feb. 19.______________________________________________________________________

22 SUN. ( 7 UT= 2 EST) Jupiter at east quadrature.(11 UT= 6 EST) Moon 4.7 N.N.W. of Mercury (only about 10 from the Sun).

23 Mon. ( 7:41 UT= 2:41 EST) Moon new. Beginning of lunation 1102. 25 Wed. ( 0 UT=19 est) Mars stationary in right ascension; begins retrograde (westward)

motion. The stationary moment in longitude is 24 hours earlier.( 7 UT= 2 EST) Moon 5.5 N.N.W. of Neptune (25 from Sun in evening sky).

26 Thu. (14 UT= 9 EST) Moon 6.3 N.N.W. of Venus (39 from Sun in evening sky). 27 Fri. (23 UT=18 EST) Moon 5.5 N.N.W. of Uranus (about 54 from Sun in evening

sky). 28 SAT. ( 4 UT=23 est) Uranus crosses equator northward. This is the last part of a triple

event: Hranus entered the northern celestial hemisphere on 2011 Apr. 9, looped backsouthward on 2011 Oct. 16, now definitively moves to the north, where it will be till2053 July 16.

______________________________________________________________________ 30 Mon. (12 UT= 7 EST) Moon 4.4 N.N.W. of Jupiter (about 82 from Sun in evening

sky).(18 UT=13 EST) Moon at apogee. Distance 63.39 earth-radii.

31 Tue. ( 4:11 UT=23:11 est) Moon at first quarter.( 8 UT= 3 EST) Saturn at greatest latitude north of the ecliptic plane (2.5). This

heliocentric event occurs only once in the 29-year orbit of Saturn.

The Milky Way on January evenings crosses overhead diagonally from southeast to north-west.

Astronomical Calendar 2012 7

January

1 SUN. ( 0:06 local time) Upper culmination of Sirius (it crosses the meridian). Jan. 1 issaid to be the date when this happens at midnight. Actually it happens even nearer toJan. 2 0h; and in later years will happen nearest to midnight on later dates, becauseof precession (see Sky & Telescope, 2008 Nov., p. 91).

( 6:15 UT= 1:15 EST) Moon at first quarter. 2 Mon. (20 UT=15 EST) Moon at apogee. Distance 63.43 earth-radii.

(24 UT=19 EST) Moon 4.8 N.N.W. of Jupiter (about 108 from Sun in eveningsky).

4 Wed. Quadrantids. See METEORS. Quite favorable year for this major shower. 5 Thu. ( 0 UT=19 est) Earth at perihelionthat is, nearest to the Sun. The date varies

(because of the swinging of Earth and Moon around their barycenter) from about Jan.1 22h near last-quarter Moon as in 1989, to Jan. 5 8h near first-quarter as in 2020. TheSun-Earth distance also varies; this year, it is about 0.98327 a.u. (147,096,000 km).Perihelion and aphelion hardly affect our warmth, as they do for Mars. See aphelion,July 5; aphelion of Mars, Feb. 15; and Astronomical Companion, SEASONS.

Latest sunrise (7:22 a.m.) at latitude 40 north. See more fully under earliest sun-rise, June 14.

(10 UT= 5 EST) Moon 2.8 S. of Pleiades (about 135 from Sun in evening sky). 6 Fri. ( 6 UT= 1 EST) Moon 5.9 N. of Aldebaran (about 144 from Sun in evening

sky).(14:29 UT= 9:29 EST) Moon at descending node (longitude 74.1).

7 SAT. Eastern Orthodox Christmas, at least as celebrated by Old Calendarists stillusing the Julian calendar, in which Dec. 25 is now 13 days after Gregorian Dec. 25(see Jan. 14). In the 19th century it fell 12 days after Christmas, on Jan. 6, so there issome confusion with the Twelve Days of Christmas, ending on Epiphany, Jan. 6, theAdoration of the Magi.

(21 UT=16 EST) Mercury at descending node through the ecliptic plane._____________________________________________________weeks____________

8 SUN. (24 UT=19 EST) Mars at greatest latitude north of the ecliptic plane (1.8). 9 Mon. ( 7:31 UT= 2:31 EST) Moon full. See SPECIAL MOONS.

(16 UT=11 EST) Moon 10.0 S.S.W. of Pollux (175 and 172 from Sun in themidnight sky).

10 Tue. (19 UT=14 EST) Moon 5.5 S. of Beehive Cluster (162 from Sun in morning sky). 12 Thu. ( 7 UT= 2 EST) P/2006 T1 Levy at perihelion, 1.0069 a.u. from the Sun. See

COMETS.( 9 UT= 4 EST) Moon 5.5 S.S.W. of Regulus (142 from Sun in morning sky).

13 Fri. Friday the 13thsupposed to be very unlucky because both the day and thenumber are unlucky. (In South America the unlucky day is Tuesday and in Italy theunlucky number is 17. In Iran women stay outdoors on the 13th day of the year toavoid bad luck.) This year has three Fridays-the-13th: see April and July. They occurevery year, either once or twice (each in 42-44 years per century) or 3 times (14 or15 years per century: common years beginning with Thursday, such as 1981, 1987,1998, 2009, and 2015, when, occurring in February, it must also occur in March; or,most rarely of all, leap-years beginning with Sunday, such as 1984, 2012, 2040, 2068,2096, 2108). Actually, Friday falls on the 13th more often than any other day does!(Because Sunday most often falls on the 1st.) In every span of 400 years after 1582(beginning of the Gregorian calendar) the numbers of Sundays-the-13th, Mondays-the-13th etc. are: 687 685 685 687 684 688 684.

( 3 UT=22 est) 78P Gehrels 2 at perihelion, 2.0082 a.u. from the Sun. SeeCOMETS.

Observers highlights for January by Fred SchaafThe highlight of the month (if youre not where the par-

tial solar eclipse is visible) could be Venus and Mercurysuperbly displayed before dawn or Jupiter and Uranuss closefinal of three conjunctions.

Venus and Mercury Both at Fine Greatest MorningElongations. For viewers around 40 N latitude, brilliantVenus rises about 3 hours before the Sun and Mercuryabout 1 hoursboth amounts nearly the maximum everpossiblein the opening days of 2011. Venus is at greatestelongation from the Sun (47 in this case) on January 8 andMercury is at greatest elongation from the Sun (23) onJanuary 9. At this time Mercury is a minimum of 24 lowerleft of Venus. On their respective dates of greatest elonga-tion, Venus glows at magnitude 4.5 with telescopes show-ing its 25- wide globe 50 per cent lit and Mercury shines at0.3 with telescopes showing its 6.7-wide globe 64 per centlit. Both planets decline somewhat as the month advancesbut Mercury does so drastically, down to rising only 40 min-utes before the Sun at months end. Venus is slding down to

the left of the vertical pattern of Scorpius during January, theplanets closest approach to Antares taking it less than 8 tothe stars upper left on January 17th. (For this months fineconjunctions of the Moon with Venus, Mercury and Antares,see note below.)

Jupiters Close Third and Final Conjunction withUranus. Jupiter is prominent and bright in the southwest atnightfall all month but its on January 3 and 4 that binocularsor telescope can show Uranus only about 1/2 to the bigplanets upper right. The globe of magnitude 2.3 yellow-white Jupiter is 38.5 wide, that of magnitude 5.9 blue (orblue-green) Uranus only 3.4 (to see its tiny dot well willrequire a night of good seeingsteady atmosphere).These two planets were in conjunction back on June 6 andSeptember 22, 2010.

Partial Eclipse of the Sun for Parts of Europe, Africa andAsia. For more details on this large partial eclipse, seeECLIPSES.

Saturn, Fairly Near Spica, Enters the Evening Sky.Saturn starts the year rising about half an half an hour aftermidnight but by the end of January is coming up around

10:30 p.m. (for viewers at mid-northern latitudes). The mag-nitude 0.8 planet rises with slightly dimmer Spica as little as8 below ituntil late in the month, when Saturn starts mov-ing with retrograde motion westward away from Spica.Saturn is at west quadrature (90 from the Sun) on January7th so the shadows cast to the side by its globe and ringsmake the system appear even more three-dimensional thanusual. Telescopic observations will be best near dawn, whenSaturn is highest, in the south.

Moon Meetings. The waning lunar crescent is lowerright of Venus on December 31, closer above Antares onNew Years Day, and lower right of Mercury on January 2.The Moon is New on January 4 and therefore is not in thenight for its light to hinder viewing the Quadrantid meteorshower (see METEORS for details). The waxing lunar cres-cent is fairly near Jupiter on the evenings of January 9 and 10.The waning gibbous Moon forms a triangle with Saturn andSpica in the pre-dawn hours of January 25. At dawn onJanuary 29 the lunar crescent is almost straight betweenVenus and Antares and on January 30 lower left of Venus.

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Jan. 9, 45 minutes before sunriseJan. 9, 45 minutes before sunrise6:37 a.m. EST (= Jan. 9, 11:37 UT)6:37 a.m. EST (= Jan. 9, 11:37 UT)

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ECLIPSES by Joe RaoA 4-eclipse year with variety: One annular and one totalsolar and one partial lunar and one penumbral.Widespread interest is likely in advance of the annular eventin May, the first central solar eclipse to cross the contiguousU.S. in nearly two decades which will also result in a wide-ly visible partial eclipse across North America. And inNovember, Australia gets an opportunity to host the firsttotal solar eclipse since 2010.

In 2012, as in most years, there are two eclipse seasons,slightly less than six months apart. (For more clarity on thissee the Pattern of eclipses diagram on page 39 of the latestreprinting of the Astronomical Companion, which showseclipses through the year 2021.) Shifting ever backwardthrough the year, our first eclipse season for this year (whichin 2011 straddled June-July) now straddles May-June and theother comes in November. In each of these eclipseseasonsagain as in most yearswe have one eclipse ofeach kind, thus making 4 in all, the minimum and most fre-quent number.

In each pair this time, it is the solar eclipse which fallsnearer to the middle of the eclipse seasonthe momentwhen the line of the nodes coincides with the Sun-Moon-Earth lineso the solar eclipse is central, of the annular vari-ety in May and the more spectacular total kind. At the first

eclipse season, thelunar eclipse is par-tial, the Moon pass-ing well to the northof the center of theEarths shadow thusonly part-waythrough the darkumbra. At the sec-ond season, theMoon passes aneven greater dis-tance from the center of the Earths shadow, but now to thesouth. It fails to make contact with the umbra, interactingonly with the much fainter penumbra.

Of this years two solar eclipses, onethe annularisthe first central solar eclipse to be visible from any part of thecontiguous (48) United States in nearly two decades, whilethe total is the first visible from anywhere on Earth in nearly28 months, though unfortunately not from America. Of thefar less interesting lunar eclipses, the May event will be visi-ble for most of the Americas in the pre-dawn hours; inNovember, the Far West may get a good glimpse beforemoonset. But if you miss that one because of weather or

where you live, its no great loss: penumbral eclipses areunderwhelming, to say the least.

My usual thanks are in order to Mr. Raymond Brooks ofStar Engineering in Arizona, for providing the precise timesfor the midpoints of the eclipse seasons, as well as reviewingmy original manuscript and making helpful suggestions. Mythanks go also to meteorologist Jay Anderson for the raw cli-matological data and narrative summaries available online ateclipser.ca . . . == a web page that is devoted to eclipses, tran-sits, occultations and other astronomical events in whichweather conditions play an important role. Go to:http://home.cc.umanitoba.ca/~jander/

SunSun

full Jan. 9

full Jan. 9

new Jan. 23

new Jan. 23full Feb. 7

full Feb. 7new Feb. 21new Feb. 21

full Mar. 8full Mar. 8

new Mar. 22new Mar. 22

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38 Astronomical Calendar 2012SCHEMATIC VIEW summarizing the years eclipses. At each date of new or fullMoon, the Earth is shown with the Moon inward of it at new Moon, outward atfull Moon. The plane of the Moons orbit at the time is shown in blue, paler forthe half lying south of the ecliptic. This plane gradually rotates backward. Thereis an eclipse if the Moon is full or new when it is in the ecliptic plane, that is,close to the time it crosses the ascending node of its orbit or the oppositedescending node. The black arrow is the moons course over 7 days. The viewis from ecliptic longitude 270, latitude 30. Relative to the Earths orbit, theSuns size is exaggerated by 15, Earth and Moon by 600, and the Earth-Moondistance by 40; the inclination of the Moons orbit is exaggerated from 5 to 10.

The lunar eclipses For the solar eclipses go to page 42

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Partial lunar eclipse of June 4 Alltimes U.T.May 26, 01:55:33Middle of eclipse

season; Sun at same longitude asdescending node.

June 3, 12:56 Moon at perigee.222,752 mi (358,485 km).

20:38Moons center reaches ascend-ing node through ecliptic.

June 4, 08:48penumbral eclipsebegins; first contact of Moon withEarths shadow.

10:00partial eclipse begins; first con-tact of Moon with Earths umbra.

11:03middle of eclipse: Moon isnearest to center of Earths shadow.The umbral magnitude of the eclipseis 0.3704; that is, the umbra reachesacross that fraction of the Moonsdiameter.

11:12Full Moon (Moon at oppositionto the Sun in ecliptic longitude).Moons center is exactly north of thecenter of the Earths shadow as mea-sured perpendicularly to the ecliptic.

11:12Moon at opposition to the Sunin right ascension; its center is exact-ly north of center of Earths shadowas measured perpendicularly to theequator.

12:06partial eclipse ends; last con-tact of Moon with Earths umbra.

13:18penumbral eclipse ends; lastcontact of Moon with Earths shad-ow.

This is eclipse number 25 of the 80 inlunar saros series 140 (1597 Sept. 25 to2968 Jan. 6).

Penumbral lunar eclipse ofNovember 28 All times U.T.Nov. 17, 21:00:57Middle of

eclipse season; Sun at samelongitude as true ascendingnode.

Nov. 27, 17:05Moons centerreaches descending nodethrough ecliptic.

Nov. 28, 12:15Penumbraleclipse begins; first contact ofMoon with Earths shadow.

14:33Middle of eclipse: Moonnearest to center of Earthsshadow. The penumbral magni-tude of the eclipse is 0.9155;that is, the penumbra reachesacross that fraction of theMoons diameter.

14:46Full Moon (Moon atopposition to the Sun in eclipticlongitude). Moons center isexactly south of center ofEarths shadow, as measuredperpendicularly to ecliptic.

14:46Moon at opposition toSun in right ascension; its cen-ter is exactly south of center ofEarths shadow, as measuredperpendicularly to ecliptic.

16:51Penumbral eclipse ends:last contact of Moon withEarths shadow.

20:09Moon at apogee.252,501 mi (406,362 km).

This is eclipse no. 11 of the 73 inlunar saros series 143 (1832 Aug.11 to 3094 Sep. 16).

VIEWS TOWARD THE MOON at successive stages of its encounter with theEarths shadow. This is what can be seen from almost everywhere on thenight side of the Earth. The umbra and penumbra are represented by cross-sections through them at the distance where the Moon is. They are visibleonly where they fall on the Moon. The umbra has a fairly abrupt edge; itsdarkness and color vary with atmospheric conditions around the Earth. Thepenumbra is imperceptible except in its inner part. The umbra gets narroweras it goes farther away; the penumbra, wider. A circle between them repre-sents the size of the body casting the shadows: the Earth we are standing on.Arrows show the motion of the shadow and the Moon over a span of 8 hours.The Moon moves faster because it takes only a month to go around the sky,while the shadow (like the Sun opposite to it) takes a year. However, since theshadow does move along somewhat during the eclipse, the diagram, repre-senting the relation of the Moon to the circular umbra and penumbra, cannotbe exactly true in all respects: the Moons ought to be slightly wider apart.Any star shown in the field is plotted in relation to the Moon and shadow atthe middle moment of the eclipseand as seen from the center of the Earth.

ei12-1.qxd 01/09/2011 07:44 Page 38


III. November 13-14Total Eclipse of the Sun(Australia, South Pacific)The second solar eclipse of the year is central and occurs just13 hours before the Moon reaches perigee. That is why thiseclipse is total. It will be the first such eclipse since 2010 July11 (which, like this one, was visible chiefly over the openSouth Pacific). The 2012 event is confined mainly to thesouthern hemisphere, where the partial phases will be visiblefrom all of Australia, New Guinea and New Zealand, as wellas a part of Antarctica and a far-southern slice of SouthAmerica. But totality will be seen only from a narrow corridorrunning southeast across Australias Northern Territory andQueensland. The calendar date here is Wednesday, Nov. 14.

Story of the shadow. The umbra first touches Earth on the UTdate of Nov. 13 at 20:35, in Arnhem Land at the northeasterncorner of the Northern Territory; the path is 78 mi (126 km)wide and totality lasts 1 minute 40.9 seconds. The northernpart of the umbra falls on the adjacent Arafura Sea, whichoverlies the continental shelf between Australia and NewGuinea. The North and South Goulburn Islands, in Auray Bayoff the northern Arnhem Land coast, are just inside the shad-ows northern edge and lie just to the east of the sunrise ter-minator. The islands are Aboriginal-owned, so permits fromthe Northern Land Council are needed for all visitors. TheGoulburn Islands are not set up for tourism, but intrepidsailors and fishermen occasionally visit.

The Arnhem Region (population 16,230) was declared anAboriginal Reserve in 1931, one of Australias largest, knownfor its isolation and its peoples strong traditions and art. TheYolngu people of the northeast are one of Australias largestindigenous groups. Malays and Macassans have raded withthe Aboriginals of this region since before Europeans arrived.

Darwin, capital of the Northern Territory, is 155 mi (240km) west of the umbras first contact. It has sunrise at 6:11a.m. and maximum eclipse (with a magnitude of .982) 4 min-utes earlier. Thus the dawn twilight may appear unusuallysubdued, and when the Sun appears above the east-south-east horizon Darwins 124,800 may see it as a narrow cres-cent with cusps pointing downward. I calculate the eclipsemagnitude at that moment to be .920.

The umbra takes only two minutes to cut southeast acrossthe Gulf of Carpentaria, a large shallow bay off the ArafuraSea. The shadows southern edge grazes the north shore ofBickerton Island, home to an Aboriginal community of 140,then crosses the northernmost part of Groote Eylandt, ownedby, the Anindilyakwa people (who speak the isolatedAnindilyakwa language).

At 20:38 UT the umbra begins a two-minute passageacross northern Queensland (named for Queen Victoriawhen it separated from New South Wales in 1859, though

a n o t h e rsuggestion wasto call it Cooksland).Eclipse chasers will proba-bly congregate in Cairns (popula-tion 147,100 in 2010, and rapidly growing),which is in the totality path, only 11 mi (18 km) south of thecenter line. Cairns is tourist-popular because of its tropical cli-mate and access to the Great Barrier Reef (reachable by boatin less than an hour) and Daintree National Park and CapeTribulation (about 81 mi or 130 km north).

For Cairns, sunrise is at 5:35 a.m. local time; just 10 min-utes later, first contact, when the Moon begins to dent theSuns disk at the 11 oclock positionk. Over the next 53 min-utes that dent grows, till the solar disk is a narrow crescent.At 6:38:34 a.m., the last bit of the Suns photosphere is extin-guished, the glorious corona spreads into view, the sky dra-matically drops to its darkness of 30 or 40 minutes beforesunrise. Totality lasts 1 minute 58 seconds, but you canextend this by 7 seconds if you travel from Cairns north to thecenter line (roughly midway between Clifton Beach and PortDouglas). For totalitys onset at Cairns the Sun is 13.8 abovethe east-southeast horizon. The umbra is now an ellipse, itsmajor axis measuring 88 mi (143 km).

As the solar crescent dwindles, some of the brightest starsand planets will appear. Discernible several minutes beforetotality will be Venus, at magnitude 4.0, 32 to the upperleft of the fading Sun; later, Saturn (magnitude +0.6) almostmidway between Venus and the Sun; on the opposite side ofthe sky, but only 6 above the west-northwest horizon,Jupiter, next in brightness to Venus at mag. 2.8.

The three brightest stars will be in the sky: Sirius (1.4)about halfway up from the west-southwest horizon; Canopus(0.8) one-third up in the south-southwest; Alpha Centauri (0.3) 24 high in the southeast. The stars of Orion and his ret-inue may appear low in the northwest.

The shadow travels out over the Pacific with no furtherlandfall. The 2,141 inhabitants of tiny Norfolk Island (one ofAustralias external territories) will witness a tantalizing partialeclipse of magnitude .980 at 8:38 a.m. local time as thesouthern limit of totality passes a mere 60 mi (96 km) to thenortheast.

A few minutes later, the shadow crosses the InternationalDate Line and the date of the eclipse switches to Tuesday,November 13.

The instant of greatest eclipse occurs at 22:11:48 UT.Duration of totality reaches 4 minutes 2.2 seconds, the Sunstanding 68 above the ocean.

The path of totality comes to an end 610 mi (980 km)west-northwest of Santiago, Chile, at 23:48 UT; the umbraleaves Earths surface along the sunset terminator, about mid-

way between the San Felixand San Ambrosio Islands (to the

north) and Juan Fernndez Islands (tothe south).

Weather prospects. Over the North Territory andQueensland, June, July and August are the dry season, withplentiful sunshine and little or no rain. January, February andMarch are the wet season: monthly rain totals average 12 to16 inches (300 to 400 mm) with much cloud and humidweather. The Intertropical Convergence Zone is a belt ofheavy cloud and frequent tropical showers and thunder-storms, known in Australia as the monsoon trough, and asthe southern hemisphere summer approaches this trough ismoving south from Indonesia toward northern Australia.Also, during the summertime, a thermal low pressure sys-tem usually develops over the Northern Territory, contribut-ing to mid and high level cloudiness and scattered precipita-tion, often affecting northern Australia. Finally, summerbrings steady east-southeast trade winds, which transporthumid air from the Pacific, which in turn interacts with asteeply rising coastal mountain range to generate local cloudsand precipitation.

But wait, you might say, the eclipse comes in mid-November, which is not yet summer but more like mid to latespring. Yes, but its still close enough to the onset of sum-mer that many of those adverse elements are beginning tobuild up. The situation is not as dire as for China and Japanat Mays eclipse, but, depending on your location, things canbe touch and go.

Across the path of totality in the North Territory andQueensland, cloud cover averages 55.2 percent; the percentfrequency of a clear sky or few or scattered clouds averages50.5. In November, Cairns averages 55 percent cloud coverand theres a 47.4 percent frequency of clear, few, or scat-tered clouds. Cairns boasts the highest number of sunnydays (7.9) anywhere in the eclipse zone. The most sanguineprospect for eclipse watchers is blue skies mixed with patchylow clouds over the ocean and along the immediate coast.One must hope that a single cloud patch doesnt block theSun at the magic moment. That happened to me at theeclipse of 1977 Oct. 12, at El Rosal, Colombia (seehttp://tinyurl.com/3z9wtpu).

The worst scenario? A cloud-filled sky thanks to a passingtrough of low pressure or perhaps a trade wind disturbancepushing a moisture-laden system onshore, bringing with it notonly heavy clouds but drenching showers.

So its a coin toss whether the weather gods will be smil-ing on the appointed morning. Mobility and advance knowl-edge of the latest weather forecasts can be the differencebetween thrill and disappointment.

a pocket-mirror with a piece of paper that has a -inch hole punched in it. Open a Sun-facing win-dow and place the covered mirror on the sunlit sill so it reflects a disk of light onto the farwall inside. The disk of light is an image of the Suns face. Farther away from the wallis better; the image will be only one inch across for every 9 feet from the mirror.Modeling clay works well to hold the mirror in place. Experiment with dif-ferent-sized holes in the paper. Again, a large hole makes the imagebright, but fuzzy, and a small one makes it dim but sharp. Darken theroom as much as possible. Be sure to try this out beforehand tomake sure the mirrors optical quality is good enough to projecta clean, round image. Of course, dont let anyone look at theSun in the mirror.

If youre around leafy trees, look at the shadow cast bythem during the partial phases. What do you see? Is itworth a photograph? You will see scores of partiallyeclipsed Suns projected through pinhole gapsbetween the leaves. Notice that it gets cool as theeclipse deepens. Does the wind pick up?

Acceptable filters for unaided visual solarobservations include aluminized Mylar. Someastronomy dealers carry Mylar filter material spe-cially designed for solar observing. Also accept-able is shade 14 arc-welders glass, available forjust a few dollars at welding supply shops. Ofcourse, it is always a good idea to test your fil-ters and/or observing techniques beforeeclipse day.

Unacceptable filters include sunglasses,old color film negatives, black-and-white filmthat contains no silver, photographic neutral-density filters, and polarizing filters. Thoughthese materials have low visible-light transmit-tance levels, they transmit near-infrared radia-tion that can burn the retina. That the Sunappears dim, or that you feel no discomfortwhen looking at it, does not mean your eyes aresafe.

Magazines such as Sky & Telescope andAstronomy will have detailed information a monthor two before May. Sometime during May, newspa-pers, especially along the path, will bring you up todate.

To all of you fortunate enough to be there, good luckand clear skies!

SKY from Cairns, Nov. 13 20:40 UT = Nov.14 6:40 a.m. clock time. Moon and Sun

are also shown over the precedingdays (Sun at 2-day intervals) to

suggest how the Moon,moving 13 times as fast,

arrives at the eclipticin time to tread on

the Sun. Theirsizes are exag-

gerated by 4.

ZE

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2012 Nov 7 21h

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ei12-2.qxd 01/09/2011 07:46 Page 44


Locations within the path of totality. *: calendar date is Nov. 14, otherwise Nov. 13.***: event is below horizon.

time 1st totality last

zone contact begins dur. alt. contact

Palmerville* UT+10h *** 6:37:28 am 2m02s 11.7 7:38 amPt. Douglas* UT+10h 5:44 am 6:38:04 am 2m03s 13.3 7:40 amCairns* UT+10h 5:45 am 6:38:34 am 1m58s 13.8 7:40 am

Total solar eclipse of November 13-14 All times U.T.Nov. 13, 19:38Partial eclipse begins: first contact of Moons penumbral cone with Earth,

at local sunrise.20:36Central Eclipse begins: first contact of axis of Moons shadow cone with Earth, at

local sunrise. Total eclipse begins slightly earlier, when leading edge of Moons umbralcone meets Earth.

22:08New Moon (conjunction of Moon with Sun in ecliptic longitude): Moons centeris exactly south of Suns as measured perpendicularly to ecliptic.

22:11Greatest eclipse: axis of umbra passes closest to the center of the Earth.22:18Conjunction of Moon and Sun in right ascension: Moons center and shadow pass-

es exactly south of Sun as measured perpendicularly to Earths equator.23:47Central eclipse ends: last contact of axis of Moons shadow with Earth, at local sun-

set. Total eclipse ends slightly later, when trailing edge of Moons umbra leaves Earth.Nov. 14, 00:46Partial eclipse ends: last contact of penumbra with Earth, at local sunset.04:41Moons center reaches ascending node through ecliptic.10:44Moon at perigee. 222,047 mi (357,361 km).Nov. 17, 21:00:57Middle of eclipse season; Sun at same longitude as true ascending

node.This is eclipse no. 45 of the 72 in saros series 133 (1219 Jul. 13 to 2499 Sep. 5).

Local circumstances for Nov. 13-14. * means that the calendar date is Nov. 14, other-wise it is Nov. 13. ! means that local sunset happens before maximum eclipse. !! meansthat the magnitude is that at sunrise; !!! means that the magnitude is that at sunset. ***means the event happens below the horizon.

time 1st max. last

zone contact eclipse mag. alt. contact

Perth* UT+8h *** 5:09 am! .401!! .0 5:42 amDarwin* UT+9h30m *** 6:11 am! .920!! .0 7:01 amAdelaide* UT+9h30m 5:43 am 6:31 am .522 16.5 7:22 amMelbourne* UT+10h 6:16 am 7:06 am .524 23.1 8:00 amPt. Moresby* UT+10h 5:39 am 6:33 am .808 11.6 7:32 amHobart* UT+10h 6:26 am 7:15 am .449 26.8 8:07 amSydney* UT+10h 6:07 am 7:03 am .669 27.1 8:04 amBrisbane* UT+10h 5:56 am 6:54 am .835 26.1 7:59 amNorfolk Is.* UT+11h30m 7:31 am 8:38 am .980 42.2 9:52 amSantiago AST 6:50 PM 7:22 PM! .585!!! .0 ***Stanley AST 6:41 PM 7:19 PM! .345!!! .0 ***

But trying to be mobile may beproblematic. A marathon, of all things,is to be run in Port Douglas on eclipseday! It too will draw crowds; it maycause key roads to be closed, last-minute maneuvers blocked. Andbecause the eclipse comes early in themorning, any prospective hunt for clear-er sites must begin in predawn dark-ness. Hundreds of others may be outthere searching. So do you go out wan-dering unfamiliar roads in the dark orstay put?

Notes Jay Anderson: . . . you aregambling on the advantages of a littlebit of mobility versus playing the proba-bilities on eclipse day by remainingfixed. If, on the sunrise, it turns out thatthe other side of Port Douglas looksbetter, you may encounter some diffi-culties in crossing through the town inthe marathon crowds. From PortDouglas to Mount Molloy, the highwayis a twisting, climbing road surroundedby dense vegetation with few outlookstoward the sea. There are almost noopportunities to pull over and watchthe sky, and since the terrain faces intothe trade winds, there is a high proba-bility of cloudiness as the air flowsthrough the gap in the mountains. All-in-all, coast observers might be betteradvised to sit and take whatever natureoffers, but it will be a heartbreaker if theeclipse is visible at a site a few hundredmeters away while being obscured atyour chosen location.

Better prospects might be foundwest of the mountains that form theGreat Dividing Range. Moisture fromthe easterly trade winds tends to collecton the windward side and get wrungout on the lee or downslope westernside. This favors the west side ofDaintree National Park. Of course,because the Sun is lower than 15, youmust take care that it isnt behind amountain or other obstruction. But sta-tistics generally show less cloud overinland areas than on the coast.

A location that stands out in thisregard is Palmerville, almost on the cen-ter line and with an average cloud cover of just 32 percent,and 77.1 percent frequency of clear, few, or scattered clouds.

But the problem is getting to Palmerville! From PortDouglas or Cairns its a long arduous trek, first south andsouthwest right out of the totality path before turning to thenorthwest at Almaden and back up into the path.

Before you decide this is where you want to be, heed JayAnderson: Inland areas are sparsely populated, poorly sup-plied by roads, subject to flooding and closure, and not capa-ble of handling large groups of tourists. This is not a route forthe uninitiated; service stations are non-existent. It would besensible to go with local guides. All-in-all, a grand adventure,but not one to be taken by bus-loads of casual tourists.

Saros series and coming attractions: This solar eclipse is the45th in a series (number 133) that started with twelve partialeclipses, the first over the Beaufort Sea on 1219 July 13.Then came 6 annular eclipses and one annular-total (hybrid)eclipse on 1544 Jan. 24. Since then, there have been 25 totaleclipses in the series. In one, 1976 Oct. 23, the path also

crossed Australia. It was witnessed by astronomer GlennSchneider, with whom I grew up in The Bronx, New York.Glenns chief memories of that 1976 eclipse are of thosewho didnt see it! In his own words:

The path of totality passed directly over Melbourne, acity of no small size, and should have afforded the opportu-nity for millions to enjoy basking in the lunar shadow. Imvery sad to say, however, it was not so. Not, as some maycome to a premature conclusion, due to poor weather, butdue to a reign of misinformed terror foisted upon the popu-lace by television stations, newspapers, kiosks, and radios allblaring with incredulous warnings. No effort was made toeducate the masses who were to be blessed with totality asto how to watch the eclipse safely, and no distinction wasdrawn between totality and partial phases. The theme of thebureaucratic agencies in charge was instill fear ratherthan imbue with knowledge. Continually echoed was themantra THE ONLY SAFE WAY TO SEE THE ECLIPSE IS ON TV. And thisfrom the heart of the path of totality!

Lets hope there wont be another Eyes Down on E-Day

campaign this time; that people will be properly instructed oncaution during the partial phases (see our suggestions forMay 20) but also that the precious moments of totalityshould not be missed. With the Sun itself hidden, its gloriouscorona can, without any special filters, be viewed in com-plete safety.

Saros series 133 will produce 20 more total eclipses, then7 partials, the last on 2499 September 5, over AntarcticasVictoria Land.

Next year, on November 3, the path of a hybrid solareclipse will stretch southeast from off the coast of theCarolinas and across the North Atlantic, making landfall atGabon and then turning east-northeast across equatorialAfrica before ending over southern Ethiopia. Extraordinarily,this eclipse is annular for only 15 seconds at the beginningbefore becoming total for the rest of the path. The durationof totality will reach a maximum of about 100 seconds at apoint in the Atlantic several hundred miles off the coast ofLiberia.

3030S3030

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2012 Nov. 132012 Nov. 1322:00 UT22:00 UT

23:0023:00

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sun

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flight of the umbra in 1 hour

(relative to Eartj cemter)

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flight of the Earth in 1 minute


CAPRICO

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SAGITTARIUS

SAGITTARIUS

SCORPIUSSCORPIUS

SCORPIUSSCORPIUS

VIRGO

the Teapot

the Teaspoon

Regulus

AntaresAntares

Spica

20112011

20132013

Jan

Feb MarApr

May

JunJulAugSepOctOctNovNovDecDec

Aug 15Saturn

Nov

27

Nov

27

Plut

oPl

uto

ecliptic longitudeecliptic longitude

eclip

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-15-15

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Coordinates of 2012Coordinates of 2012

OPHIUCHUSOPHIUCHUS

HELIOCENTRIC VIEW of the orbit of Mars. The view is as in theMercury-Venus picture, but with the constellations removed

from the front side of the sphere for clarity. A circle on the eclip-tic plane shows the mean distance of Mars from the Sun (1.5237

a.u.). The planets are exaggerated 700 times in size. Dashed lines(each dash or gap 0.05 a.u. long) connect the positions of Earth and

Mars at the dates of several successive oppositions. A dotted line con-nects them at the date when Mars is nearest, 2 days different from this

years opposition. Before opposition Mars is in the morning sky, and afterit in the evening sky, as shown by the resphctively gray and black curves.

Marss summer solstice is (as for the Earth) when its north rotational pole is tilt-ed most toward the Sun, and autumn equinox is when the pole is tilted backward.

The equatorial plane of Mars makes a circle around the sky perpendicular to this pole,cutting its orbital plane in the directions of Marss equinoxes.

THE DISK OF MARS at the beginning of eachmonth. The scale is 1 millimeter to 1 second ofarc. The diagrams are oriented so that the eclip-tic plane (almost the same as the planets orbitalplane) is horizontal. Short lines point to thenorth and south ecliptic poles; longer lines to thecelestial poles. Direction to the Sun is shown byan imaginary stick, starting at the center of theplanet (under the dot) and projecting one planet-radius beyond the surface. An arrow alongMarss equator represents its rotation in 2 hours.

Jan 1Feb 1Mar 1Apr 1May 1Jun 1Jul 1Aug 1Sep 1Oct 1Nov 1Dec 1

Mar 3opposition

ecliptic

north

equatorial

north

rotation

in 2 hours-------------------

direction

to Sun-------------------

north

polar cap----------

Mar 3Mar 30h0h

0h Mar 30h Mar 3

Mar 4Mar 40h0h

6h4h

3h

equatorial

ecliptic

1h2h

5h

PhobosPhobos

DeimosDeimos

3h

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15h12h

9h

6h

MARSA year with an opposition, of the northerly but more distant kind. This climax comes inMarch, after which Mars spends the rest of the year sinking in the evening sky.

Mars orbits 1 times farther out from the Sun than Earth, taking 1.88 of our yearsto complete an orbit. On our inside track, we take 2.13 years to catch up with

Mars at the next opposition. Thus the oppositions are spaced around the skyroughly 1/7 of the circle apart, in a roughly 15-year cycle. After the opposi-

tion of 2010 Jan. 29 in Cancer, Mars spent the rest of that year semicirclingaround to Sagittarius, then 2011 semicircling back and a little more.

This January, as we again overtake it, Mars slows its eastwardprogress across the starry background and appears to swirl backwardtoward us, curling into the 81-day retrograde loop that is its time ofprominence. It is in the part of its tilted and eccentric orbit that isnorthernmost (maximum latitude Jan. 8) and outermost (aphelionFeb. 15), so the loop is a northward one, and at opposition onMarch 3 the planet is still almost as distant as it can be, less than14 wide and shining at magnitude 1.2 (whereas at the near

e c l i p t i c

ecliptic

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m e a n d i s t a n c e

AQUAR I US

AR IE S

CANCER

CAPR I CORNUS

GE MI N I

EO

P I S CE S

T AURUS

M a r s

SunSun

E a r t h

2012 Mar 3

Mar 5

2010 Jan 29

2014

Apr

8

2016M

ay 22

2018 Jul 27

2005Nov 7

2003Aug

28

2007Dec 24

northernmostlatitude

aphelion

autumnequinox

Mar

JanSep

Aug

Jul

Jun

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OctNovDec

Febsouthernmost

latitude

Jan

Feb

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JunJul

Aug

Sep Oct

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E CL I

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PLAN

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ticno

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north pole

Mar

s ro

tatio

nal

north

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summer

solstice

mean dist. from sun 1.52 a.u.sidereal period 1.88 years = 687 dayssynodic period 2.13 years = 780 dayseccentricity .093inclination 1.9diameter 6,790 kmsatellites 2

MARS AND SATELLITES at opposition. Equatorial north is at top, to suit observation in telescopes.Scale is 1 mm to 1 second. The satellites go around Mars in almost circular orbits and in planes slight-ly varying from its equator. They are shown at hourly intervals, starting at 0h UT, which is 7 p.m. EasternStandard Time or 4 p.m. Pacific Standard Time ON THE PREVIOUS CALENDAR DATE. The orbits are drawnthicker where the satellites are nearer to us than the center of the planet. Phobos goes around in only7.65 hours, Deimos in 30.3 hours. Since Mars rotates in 24 hours, Phobos travels more than threetimes faster than the planets surface: seen by a Martian, Deimos goes over slowly from east to west(more than 2 days from rising to setting), but Phobos goes in the opposite direction, rising in the westand setting in the east, twice a day! (Compare the arrow on Marss equator, representing rotation in2 hours, with Phoboss larger movement in half that time.) The satellites are exaggerated 30 times insize. Both are elongated: dimensions of Phobos are 27x22x19 kilometers, and Deimos 15x12x11 (asagainst the 6800 km diameter of Mars). Look closely and you will see that they are shown as ellipses.They rotate synchronously: that is, keep the same face to Mars. They are very faint: at this time themagnitude of Mars is 1.2, whereas Phobos and Deimos are about 13 and 14 magnitudes fainter.

mars.qxd 01/09/2011 07:42 Page 54

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pr 1

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1 P Ha l l e

y

1 P H a l l e y


HELIOCENTRIC VIEW of all the planets from Earth(smallest ellipse) outward. The whole orbits areshown in blue (with stalks to the ecliptic plane atyearly intervals); paths for this year in black (stalksmonthly). Besides the major planets, we show afew minor bodies (of which there could be thou-sands in the picture): dwarf planet Pluto; asteroid1 Ceres (as an example of the Main Belt of aster-oids between Mars and Jupiter); and Comet 1PHalley, which at its last visit was first observed in1982, and now, on the scale of the picture, is near-ly 18 cm (7 inches) from the Sun, approach its 2023aphelion. The viewpoint has receded to a distanceof 100 astronomical units. The equatorial andecliptic planes are represented by circles aroundthe sky at a distance from the Sun of 35 a.u. Eachdash or gap in the opposition lines is 0.5 a.u. long.

TABLE OF PHENOMENA. For explanation see the MERCURY and VENUS section.Mars r.a.(2000)dec. hedis gedis elo mag dia

Jan 1 0 11 27 41 6 41 1.656 1.040-110 .2 9.0

Jan 5 12 1- au from earth 11 31 33 6 25 1.658 1.000-113 .1 9.4

Jan 8 24 max.lat.north 11 34 8 6 15 1.659 .970-116 .0 9.7

Jan 24 1 stat.in long>retr 11 39 43 6 7 1.663 .848-130 -.3 11.0

Jan 25 0 stat.in r.a.>retr 11 39 45 6 9 1.664 .841-131 -.4 11.1

Feb 15 21 aphelion 11 28 10 7 57 1.666 .713-157 -.9 13.1

Mar 3 20 opposition 11 5 38 10 21 1.665 .674-176 -1.2 13.9

Mar 5 17 nearest to earth 11 2 49 10 37 1.664 .674 175 -1.2 13.9

Apr 5 14 max.declin.north 10 28 6 12 57 1.654 .769 138 -.6 12.2

Apr 14 4 stat.in long>dir. 10 25 47 12 47 1.649 .822 129 -.4 11.4

Apr 15 12 stat.in r.a.>dir. 10 25 45 12 43 1.649 .831 128 -.4 11.3

May 8 9 1+ au from earth 10 36 40 10 43 1.633 1.000 109 .1 9.4

Jun 8 2 east quadrature 11 15 37 5 46 1.605 1.244 90 .6 7.5

Jul 5 1 on equat.,to sou. 12 2 51 0 4 1.576 1.447 77 .9 6.5

Jul 24 22 descending node 12 42 59 -4 36 1.552 1.582 69 1.0 5.9

Aug 17 9 2.9S of Saturn 13 35 23 -10 17 1.522 1.725 61 1.1 5.4

Nov 17 21 max.declin.south 18 1 52 -24 32 1.413 2.109 35 1.2 4.4

Nov 27 11 4.6S of Pluto 18 33 53 -24 20 1.405 2.137 32 1.2 4.4

Dec 29 5 max.lat.south 20 19 26 -20 45 1.386 2.218 25 1.2 4.2

Jan 1 0 20 28 32 -20 14 1.385 2.225 24 1.2 4.2

CAPRICO

RNUS

LEOLEO

LIBRALIBRA

SAGITTARIUS

SCORPIUS

SCORPIUS

VIRGOVIRGO

the Teapot

the Teaspoon

RegulusRegulus

Antares

SpicaSpica

2011201120112011

2013

JanJan

FebFeb MarMarAprApr

MayMay

JunJunJulJulAugAugSepSepOctNovDec

Aug 15Aug 15Saturn Saturn

Nov 27

Pluto

ecliptic longitude

ecliptic latitude

-15

-10

-5

0

+ 5

+10

+15315 300 285 270 255 240 225225 210210 195195 180180 165165 150150 140140

+15+15

+10+10

+ 5+ 5

0

-5-5

-10-10

-15-15

1 0 h 11 h 1 2 h

1 3 h 1 4 h 1 5 h 1 6 h 1 7 h 1 8 h 1 9

h 2 0

h

2 1h

+2 0 o+ 1 0 o

- 1 0o

- 2 0o

- 3 0o

eqq

uuaa t oo

r

e c l i p t i ce c l i p t i c

Milky Way

Coordinates of 2012

opposition Mar 3

MarsOPHIUCHUS

--3--2--1012345

m a g n i t u d es

opposition of 2003 it was 2.9, nearly 5 times brighter). Since it has begun to move inward,the moment when it is nearest to Earth comes two days after opposition (this is an effect that,because of the eccentricity of Marss orbit, is more pronounced than for other planets).

The loop takes it back through Leo, almost to Regulus which it passed last November.April is when we definitively leave Mars behind; we are rounding our orbit as we look fartherback at it, so the apparent eastward motion against the stars resumes (stationary momentApril 14) and becomes rapid, out of Leo and across Virgo and four more constellations to endthe year in Capricornus.

When on Aug. 14 and 15 Mars passes between Spica and Saturn (an orange pointbetween a white point of the same brightness and a yellow point a little brighter), this groupis still about 60 up-left from the setting Sun. And not much dimmer or lower when the slen-der Moon climbs past beneath them a week later.

MAP of Marss geocentric track against the starry background, ecliptic-based like the Mercury and Venus maps. The scale is about 2.7 mm to 1.The track is drawn in gray when Mars is in the morning sky (before oppo-sition). Parts of the tracks for the neighboring years are included (in blue).Short blue lines connect Mars to other planets when they appear closest.

mars.qxd 01/09/2011 07:43 Page 55

aphelion

ee qu a

t or

M e r cu

ry

11 P

ar

th

en

op

e

1 C e re s

e cl i

p ti c

p la n

e

v e rn a l

e qui n o

x di r e

c t ion

- -- 1

AU- -

-

e cl i p

t i c

ecliptic

equator

V e n u sE a r t h

M a r s

J u p i t e r

2 P al l a s

3 J u n o

4 V e s t a

SunSun

opposition

opposition

opposition

opposition

opposition

aphelion

perihelion

AQUARIUSAQUARIUS

ARIESARIES

CAPRICORNUSCAPRICORNUS

CETUSCETUS

ORIONORIONPISCESPISCES

SAGITTARIUSSAGITTARIUS

TAURUSTAURUS

AltairAltair

SiriusSirius

MiraMira

Vega

RigelRigel

BetelgeuseBetelgeuse

Algol

Fomalhaut

Aldebaran

Aldebaran

JanJan

1 Ceres

1 CeresFebFeb

MarMar

AprApr

MayMay

JunJun

AugAugSepSepOctOct

Nov

Nov

DecDec

JanJan

2 Pallas2 Pallas

FebFebMarMar

AprAprMayMay

JunJunJulJul

AugAug

SepSep

OctOct

NovNovDecDec

JanJan

4 Vesta

4 Vesta

FebFeb

AprApr

MayMayJunJun

JulJulAugAugSepSep

NovNov

JanJan

11 Parthenope

11 Parthenope

FebFeb

MarMar

AprApr

MayMay

JunJunJulJul AugAug

SepSep

OctOct

DecDec

right ascensionright ascension

declination

declination

-20-20

-10-10

0

+10+10

+20+20

+30+3030m30m 6h6h 5h5h 4h4h 3h3h 2h2h 1h1h 0h0h 23h23h 22h22h 21h21h 20h20h 19h19h 18h30m18h30m

+30+30

+20+20

+10+10

e c l i p t i c

e c l i p t i c

Mil ky Way

Coordinates of 2000Coordinates of 2000

PleiadesPleiades

VestaVesta

CeresCeres

0

-10-10

-20-20

El NathEl Nath


ASTEROIDSFor a second year, all of the First Four are at opposition.In addition we feature asteroid No. 11, Parthenope.

Asteroids (also called minor planets) continue to grow innumbers. In 2010, 74,082 objects were discovered or recov-ered, receiving provisional designations, and as of Aug. 2011the total of these had reached 971,095; 283,317 hadreceived numbers (recognizing that their orbits are deter-mined and they are unlikely to be lost); and 16,660 hadreceived names.

The First Four asteroids, discovered in the first years ofthe 19th century, have combinations of large size and mod-erate distance that make them reliably observable aroundeach of their oppositions. They travel each year very rough-ly a quarter of the way around the celestial sphere (Vestamore, the others less); therefore each arrives about each 3rdor 4th year in the Taurus-Gemini direction, so that it is behindus in January and still ahead of us in Decemberin otherwords it misses an opposition. This year, however, the fourare spread over an approximate hemisphere, and we over-take all of them, beginning in May with:

3 Juno. Though named for the queen of the Romangods, this third asteroid to be discovered is smaller than theothers of the First Four and often less bright than severallower down the list. This is one of the most distant anddimmest oppositions for Juno, because it is at aphelion atessentially the same time (it can be 1.33 a.u. nearer to us and2.7 magnitudes brighter, as it will be in Nov. 2018). It is atthe southern end of Serpens (Caput) near the Ophiuchus-

Libra border and 3 south of the equator; but Junos opposi-tions are always within about 5 of the equator because itswhole orbit is, owing to the place (170) and angle (13) ofits slope across the ecliptic.

11 Parthenope. At least three minor figures in Greekmythology were called Parthenope (virgin face), one ofthem being a Siren, a singing creature of the coasts, who wasregarded as the foundress of the colony of Neapolis (newcity, Naples). So when in 1849 Annibale de Gasparis, ofNaples, discovered his first asteroid, 10 Hygiea, Sir JohnHerschel commented that it might have been namedParthenope. De Gasparis followed the suggestion when hediscovered asteroid 11 on 1850 May 11. (He went on to dis-cover nine altogether, the last in 1865.) Parthenope is in anordinary Main Belt orbit. This is the nearest and brightestopposition it will have till 2031 July, though 2008 Aug. wasslightly better still.

2 Pallas has an orbit which ascends across the eclipticnear where Junos does (173) but at a steeper angle (35),so that it is a sort of counter-ecliptic, tipping north of theequator where the ecliptic tips south. This is the year ofPallass descent. In May and June it rather slowly crosses thepath of the Moon, thus getting occulted twice, before drop-ping through the ecliptic in July and taking the backward turnwhich is the beginning of a southward slide of which the mid-dle, in September, is opposition. This is one of the medium-southerly, medium-distance, and medium-bright oppositionsof Pallas. Four days after it, the asteroid passes close to thestar Iota Ceti that marks the western fin of the Whale.

4 Vesta this year, traveling on a track inside of that ofCeres, is gradually overhauling it, and we pass both of them

at opposition in December. Though only fourth to be dis-covered, Vesta is almost equal second in size with Pallas, hasa high albedo (lightness of color), and is usually closer in. Soit is, at its oppositions and at many other times, the brightestasteroid, the only one that can reach the extreme naked-eyemagnitude threshold of about 6.5. And it just manages thatthis year despite being in the outer part of its orbit (aphelionon Nov. 24). At opposition on Dec. 9, 7.3 east of Aldebaranwhich it passed in August, it is more distant and dimmer thanin surrounding yearsa tough test of its supposed naked-eyefindability! The 2014 Apr. 13 opposition will be nearer andnearly a magnitude brighter, though somewhat moresoutherly: in Virgo, 15 north of Spica and, this time, only 2days before and 2.5 west of Ceres. Because Vestas perihe-lion is in the Ophiuchus direction (longitude 254) its oppo-sitions are nearest (though southerly) when they come inMay-to-August.

On 2011 July 15, spacecraft Dawn went into orbitaround Vesta. See our SPACEFLIGHT section.

When 1 Ceres was discovered by Piazzi on 1801 Jan. 1,it was thought to be the missing planet that, according to thepattern called Bodes Law, should be in the gap betweenMars and Jupiter; but as other discoveries followed, it wasfound to be the first and largest of a new classasteroids. Itsperiod of almost exactly 4.6 years means that 5 revolutionsequal 23 Earth-years; so its performance of 2012 repeats thatof 1989, differing by only 1 days and 1. It is a highnorthern performance, between the horn-tips of Taurusthediscovery constellationwith Ceres relatively near andbrightthe best till 2018.

SPATIAL VIEW of a sphere 3.5 a.u. in radius, from a viewpoint 10.5 a.u.from the Sun. Grid-lines on the ecliptic plane are 1 a.u apart. The pathof each body is drawn for the whole year (Venus, 6 months; Mercury, 2months). Stalks to the ecliptic plane show the bodys position at the startof each month. Where it reaches opposition, a dashed line connects its

position to that of the Earth at the date; each dash or gapis 0.1 a.u. long. Oppositions shown are in longitude (dateof opposition in right ascension can be some days differ-ent). When an asteroid is in the morning sky (west of theSun) as seen from the Earth, its course is drawn in gray.

ast12.qxd 01/09/2011 07:28 Page 62


PHENOMENA (for explanation see the MERCURY section).1 Ceres r.a.(2000)dec. hedis gedis elo mag

Apr 26 9 conjunc.with sun 2 23 29 8 30 2.849 3.849 5 8.8

Dec 18 6 opposition 5 44 46 25 17 2.665 1.681 178 6.7

2 Pallas

Feb 22 14 conjunc.with sun 22 5 43 -0 47 3.309 4.278 -10 10.2

Sep 24 22 opposition 0 22 49 -7 53 2.954 1.960-170 8.3

3 Juno

May 8 17 aphelion 16 10 57 -3 46 3.353 2.393-159 10.2

May 19 19 opposition 16 2 3 -3 0 3.353 2.373-163 10.2

Dec 22 13 conjunc.with sun 18 3 51 -13 41 3.180 4.145 -10 11.2

4 Vesta

Apr 9 19 conjunc.with sun 1 22 0 3 12 2.473 3.469 5 8.1

Nov 24 20 aphelion 5 21 51 17 29 2.570 1.616-161 6.7

Dec 9 2 opposition 5 6 39 17 40 2.570 1.587-175 6.4

11 Parthenope

Jan 16 17 2.0S of Pluto 18 32 38 -21 17 2.286 3.199 -18 11.4

May 15 9 .5N of Neptune 22 20 8 -10 26 2.216 2.124 -82 11.1

Jun 29 23 perihelion 23 9 33 -7 11 2.210 1.608-113 10.5

Sep 3 4 opposition 22 57 3 -12 1 2.223 1.216-175 9.0

MAPS showing paths of the selected asteroids throughthe year. Ticks are at 1st of each month; arrowheads atend of year. Paths are thicker where asteroids arebrighter; gray where they are less than 15 from the Sun.

IC2162

M37

M35M35

Crab NebulaCrab Nebula

bEl NathEl Nath

c

zc1c2

n

k

mTejat PriorTejat Prior

n

SepSep1

1 Ceres

1 Ceres

11112121

OctOct1

1111

2121

1N

ovN

ov

11112121

DecDec1

11112121

+20+20

+22+22

+24+24

+26+26

+28+28

25m25m 20m20m 10m10m 6h6h 50m50m 40m40m 30m30m 5h25m5h25m

+28+28

+26+26

+24+24

+22+22

+20+20

e c l i p t i c

M

ilky

W

ay

Co o r d i n a t e s o f 2 0 0 0

GEMINIGEMINI

ORIONORION

TAURUSTAURUS

e

y

m

w

e

y

c

dd

e

s

zJan 11

3 Juno

3 Juno

21Feb 1112121

1Apr

Apr

1111

2121

May

May

11111

2121

Jun

Jun

1 1111 2121JulJul1

Aug

Aug

1 1

1111

2121SepSep1

1111

2121

Oct1

Oct 1

11

-8-8

-6-6

-4-4

-2-2

030m30m 20m20m 10m10m 16h16h 50m50m 40m40m 15h30m15h30m

0

-2-2

-4-4

-6-6

-8-8

e qq uu a tt oo r

Coo r d i n a t e s o f 2 0 0 0

OPHIUCHUSOPHIUCHUS

LIBRALIBRA

SERPENS (CAPUT)SERPENS (CAPUT)

NGC246NGC246

i

f1f2f3f4

2 Pallas

2 Pallas

Sep Sep1

1111

2121

Oct

Oct

1 1

1111

-12-12

-10-10

-8-8

-6-6

-4-4

-2-2

0045m45m 40m40m 30m30m 20m20m 10m10m 0h 5m0h 5m

0

-2-2

-4-4

-6-6

-8-8

-10-10

-12-12

Co o r d i n a t e s o f 2 0 0 0

CETUSCETUS

AQUARIUSAQUARIUS

AQUARIUS

NGC7492

qr

u

k

tt 1

t 2

l

d

f

yy1

c

y2y

3

2121MayMay

11 Parthenope

11 Parthenope

1JunJun

111121211 Jul Jul

AugAug1

1111

2121

1 Sep Sep

1111

21211OctOct

Nov Nov1

1111

2121

DecDec11111

-14-14

-12-12

-10-10

-8-8

25m25m 20m20m 10m10m 23h23h 50m50m 40m40m 30m30m 22h25m22h25m

-8-8

-10-10

-12-12

-14-14

e cll ii pp

tt i cc

Co o r d i n a t e s o f 2 0 00

AQUARIUSAQUARIUS

LIBRALIBRA

OPHIUCHUSOPHIUCHUS

SCORPIU

SSC

ORPIU

S

(CAPUT)(CAPUT)

SERPENSSERPENS

(CAUDA)(CAUDA)

Arcturus

AntaresAntares

JanJan

3 Juno

3 Juno

Mar

Mar

Apr

Apr

MayMayJunJun Jul

Jul

Aug

Aug

SepSep

OctOctNovNov

30m30m 18h18h 17h17h 16h16h 15h15h

0

-10-10

-20-20e cl i p t

i c

11 Parthenope11 ParthenopeJanJan

SERPENSSERPENS

SAGITTARIUSSAGITTARIUS

-20-20

-10-10

0

For more information about asteroids: The Minor PlanetBulletin of the Association of Lunar and PlanetaryObservers, www.minorplanet.info. And the Minor PlanetCenter, http://cfa-www.harvard.edu/iau/mpc.html.

ORION

NGC1647NGC1647

NGC1746NGC1746

J320

Crab NebulaCrab Nebula

d2

k1k2

u

p

q1

e

q2

r

1s2

p2

o1

p1

o2

i

bEl Nath

f1f2

z

c1

1111AugAug

4 Vesta4 Vesta

21211 Sep Sep

11112121OctOct11111

1 Nov Nov

1111 2121

DecDec1 1111 2

121

+14+14

+16+16

+18+18

+20+20

+22+22

42m42m 30m30m 20m20m 10m10m 5h5h 50m50m 4h40m4h40m

+22+22

+20+20

+18+18

+16+16

+14+14

e cc ll ii p tt ii cc

Coo r d i n a t e s o f 2 0 0 0

ORIONORION

TAURUSTAURUS

a

AldeAldebaranbaran

name discov. diam. q a Q e P ikm a.u. a.u. a.u. years

1 Ceres 1801 952 2.55 2.77 2.98 .08 4.60 11

2 Pallas 1802 524 2.13 2.77 3.41 .23 4.61 35

3 Juno 1804 274 1.99 2.67 3.35 .26 4.37 13

4 Vesta 1807 512 2.15 2.36 2.57 .09 3.63 7

11 Parthenope 1850 150 2.21 2.45 2.70 .10 3.84 5

Orbital and other facts.q: perihelion distance.a: mean distance.Q: aphelion distance.e: eccentricity.P: period, in years.i: inclination.

2

3

4

5

678m

ag

ni

tu

de

s open clusteropen cluster

nebulanebula

planetary nebulaplanetary nebula

globular clusterglobular cluster

galaxygalaxy

FINDER CHARTS on larger scale (0.75 cm per degree) forasteroids around the times of their oppositions. Position at0h UT of each day (7 p.m. Eastern Standard Time of theprevious day) is shown by a dot sized for brightness. Thedots are gray when the asteroid is in the morning sky, whitein the evening sky (into which the asteroid passes at ornear opposition). Stars are plotted from the Hipparcos cat-alogue. Projection is azimuthal-equidistant: angular direc-tions and distances are true from the middle of the chart.

Not from the stars do I my judgment pluck;And yet methinks I have astronomy,But not to tell of good or evil luck,Of plagues, of dearths, or seasons quality;Nor can I fortune to brief minutes tell,Pointing to each his thunder, rain and wind,Or say with princes if it shall go well,By oft predict that I in heaven find:But from thine eyes my knowledge I derive . . .

Shakespeare, Sonnet XIV

ast12.qxd 01/09/2011 07:28 Page 63


RISING AND SETTINGThis hourglass shows times when the Sun, Moon, and planetsrise and set, for latitude 40 north, longitude 0. (They differlittle for other longitudes, much more for other latitudes.)These are local mean times; to adjust them to your clocktime, see the Personal Reminder on the preceding page.

The lines representing days (actually drawn only for days1, 6, 11, 16, 21, 26 of each month) begin at midnight, whichis in the middle because we choose to show night rather thanday undivided. Each day-line ends at the point where thenext day starts, so there is really just one time-line, a cut andflattened helix.

local mean timelocal mean time

2012

0

0

1

1

2

2

3

3

4

4

5

5

6

6

7

7

8

8

9

9

1010

1010

1111

1111

1212 1212

1212 1212

1313

1313

1414

1414

1515

1515

1616

1616

1717

1717

1818

1818

1919

1919

2020

2020

2121

2121

2222

2222

2323

2323

1 1 1 1

1111 1111

Janu

ary

Janu

ary

2121 2121

1 1 1 1

1111 1111

Febr

uary

Febr

uary

2121 2121

1 1 1 1

1111 1111

Mar

chM

arch

2121 2121

1 1 1 1

1111 1111

Apr

ilA

pril

2121 2121

1 1 1 1

1111 1111

May

May

2121 2121

1 1 1 1

1111 1111

June

June

2121 2121

1 1 1 1

1111 1111

July

July

2121 2121

1 1 1 1

1111 1111

Aug

ust

Aug

ust

2121 2121

1 1 1 1

1111 1111

Sept

embe

rSe

ptem

ber

2121 2121

1 1 1 1

1111 1111

Oct

ober

Oct

ober

2121 2121

1 1 1 1

1111 1111

Nov

embe

rN

ovem

ber

2121 2121

1 1 1 1

1111 1111

Dec

embe

rD

ecem

ber

2121 2121

1 1 1 1

0 0

0 0

hours of sidereal tim

e


e

PISCES

PISCES

PISCES

PISCES

2 2

2 2ARIES

ARIES

ARIES

ARIES

4 4

4 4TAURUS

TAURUS

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TAURUS 6 6

6 6


e


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CANCER

CANCER1

010

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12

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12


e


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VIRGO

VIRGO

VIRGO

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14

14

14

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BRA

LIBRA

LIBRA

LIBRA1

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sits

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sits

Sun

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sits

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Plut

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Plut

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Pluto se

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Plut

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Plut

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Nep

tune

rise

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tune

rise

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Nep

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rise

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tune

rise

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Nep

tune

rise

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rise

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sets

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sets

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tune

sets

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tune

sets

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tune

sets

Nep

tune

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Uranu

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Uranu

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Uranu

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Uranu

s sets

Satu

rn ri

ses

Satu

rn ri

ses

Satu

rn ri

ses

Satu

rn ri

ses

Satu

rn ri

ses

Satu

rn ri

ses

Saturn se

ts

Saturn se

ts

Satu

rn se

ts

Satu

rn se

ts

Satu

rn se

ts

Satu

rn se

ts

Jupi

ter r

ises

Jupi

ter r

ises

Jupi

ter r

ises

Jupi

ter r

ises

Jupi

ter r

ises

Jupi

ter r

ises

Jupi

ter s

ets

Jupi

ter s

ets

Jupi

ter s

ets

Jupi

ter s

ets

Jupit

er

Jupit

er

sets

sets

Mar

s ri

ses

Mar

s ri

ses

Mar

s rise

s

Mar

s rise

s

Mar

s ri

ses

Mar

s ri

ses

Mar

s set

s

Mar

s set

s

Mars s

ets

Mars s

ets

Mar

s se

tsM

ars

sets

Venu

s rise

s

Venu

s rise

s

Venu

s ri

ses

Venu

s ri

ses

Venus rises

Venus rises

Venus sets

Venus sets

Ven

us s

ets

Ven

us s

ets

Mercury rises

Mercury rises

Mercury

Mercury rises

rises

Mercury rises

Mercury rises

Merc

ury se

ts

Merc

ury se

ts

Mercury sets

Mercury sets

Pluto oppositionPluto opposition

Neptune oppositionNeptune opposition

Uranus oppositionUranus opposition

Saturn oppositionSaturn opposition

Jupiter oppositionJupiter opposition

Mars oppositionMars opposition

QuadrantidsQuadrantids

LyridsLyrids

Eta AquaridsEta Aquarids

June June BootidsBootids

Delta AquaridsDelta AquaridsAlpha CapricornidsAlpha Capricornids

PerseidsPerseids

Alpha AurigidsAlpha Aurigids

Sep Epsilon PerseidsSep Epsilon Perseids

DraconidsDraconidsSouthern TauridsSouthern Taurids

OrionidsOrionids

Northern TauridsNorthern Taurids

LeoLeonidsnidsAlpha MonocerotidsAlpha Monocerotids

GeminidsGeminidsUrsidsUrsids

first-quarter Moon sets

last-quarter Moon rises

full Moon culminatesfull Moon rises

new Moon setsfirst-quarter Moon culminates

new Moon rises

full Moon setslast-quarter Moon culminates

Venu

s

Venu

s set

sse

ts

Mercury sets

Mercury sets

The dark zone down the middle is night, betweenthe curves of sunset and sunrise. The three border-ing gray bands are the times of civil, nautical, andastronomical twilight, which are defined as beingwhen the Sun is less than 6, 12, and 18 below thehorizon.

Slanting lines show the hours of sidereal time:that is, which hour of right ascension is on the merid-ian. Thus 0h-1h sidereal time is the AndromedaHour, when that gore of the sky is highest. Siderealhours are 10 seconds shorter than clock (solar) hoursand thus fall 4 minutes earlier each day.

The times of the Suns transit across the meridianare shown by orange spots. This time differs frommean noon by the amount called the equation oftime (see the GLOSSARY). Orange curves show where

the times of sunset and sunrise would be if the dia-gram were plotted to apparent (true solar or sundialtime, in which days vary slightly in length) instead ofmean time. Again, the difference is the equation oftime.

At a planets opposition it is up all night (roughly)and none of the day.

Meteor showes are marked at the local timeswhen their radiants are highest.

Two thick vertical lines displaced to the left insummer represent 5 p.m. and 8 a.m. by the clock (forplaces on the meridian of their time zone). Thisshows how the purpose of setting clocks back fromstandard to daylight-saving time is to approximateto the earlier rising of the Sun. In summer we call thetrue 7 oclock 8, the true 12 1, etc.

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2012 Astronomical Calendar