Star Calendar – June 2017

Star Calendar

June 2017

Star Planets:

Moon appears at First Quarter as the month opens, stands over Jupiter on the 3rd, and is then Full with Saturn on the 9th. Early risers will be treated to a complementary pairing with Venus on the 20th and 21st, the complement being of crescent/gibbous, wane and wax.

Mercury celebrates our solstice from the far side of the Sun as he makes superior conjunction on the 21st.

Venus shows her First Quarter on the 5th, then waxes as she draws nearer the Sun. Early summer sunrises, made earlier by meddling with the clocks, makes sightings less common.

Sun now reigns above the horizon 15 hours a day (in Spring Valley), varying by only 11 minutes this month. On the Solstice he stands between the stars Betelgeuse and Menkalinon — if you can recall seeing them as winter wound down; Betelgeuse is the brighter armpit of Orion and Menkalinon is that other Aurigan star one sees when looking for yellow Capella along the great Arc of Capella. The former stands right on the meridian of summer solstice.

Mars is unviewable this month. He and Mercury will have a discreet tête à tête as the latter scoots by on the 28th.

Jupiter remains prominent and southerly in the evening. He ceases his retro urge on the 10th and begins his stroll toward Libra — which he will achieve, arm-in-arm with Venus, in mid November.

Saturn is brightest this month, but never gets as bright as Jupiter at his least. Opposition is on the 15th, but, again due to fiddling with clocks, he does not culminate until 1:00AM — and then is only 27 degrees high. Use the Full Moon on the 9th to advantage in taking notice.

Star Days:

   1 Sunrise/set in Spring Valley at 5:26/20:23 (14h57m daylight)
   3 Venus at largest angle from Sun for this appearance, 46 degrees
     Moon above Jupiter in South as dark falls
   4 Moon above Spica in South as dark falls, Jupiter bright and to right
 8-9 Full Strawberry Moon at 9:10AM of the 9th
   9 Moon with Saturn and Antares, rising ESE just before 9:00PM
  10 Jupiter stationary, to normal motion (leftwards against stars)
  14 Sunrise is earliest for the year, at 5:23
  15 Saturn in opposition, brightest, middle of backwards movement
  20 Moon, waning beside waxing Venus, in East at 4:00AM
  21 Solstice at 00:24, rise/set at 5:24/20:32 (15h8m daylight)
     Sun then enters astronomical Gemini (solstice was in Taurus)
     Mercury passes far side of Sun (superior conjunction)
  23 Traditional Mid-summer, St. John’s Eve
     Moon New and Perigee, 16 hours apart (dark, with large tides)
  27 Sunset is latest for the year, at 20:33
  28 Moon nearly grazes Regulus, 9:30PM in West
  30 Sunrise/set in Spring Valley at 5:27/20:33 (15h6m daylight)

Star Calendar – May 2017

Star Calendar

May 2017

Start Calendar Planets:

Moon and Sun each elongate the fluid earth and exert tidal stress on the viscous and solid earth. This stress and shape distortion moves around the longitudinal earth in the two periods 12.42 and 12 hours respectively but also change latitude (declination) according to each body’s characteristic seasonal movement. Proximity of each body further modulates the effect. We then have a complex combination of rhythms and directions of tidal stress/distortion which serve to enhance and diminish each other. But the world is not covered evenly in fluid – there are instead basins and channels of various size that the generated tidal wave must negotiate. The size, orientation and capacity of this complex serve to also generate resonances and nodes so that local expressions of these stress inputs can appear sensibly aligned or apparently out of phase, greatly enhanced or diminished. The largest noticeable rhythm in most instances is the M2 tide (Moon tide at twice its diurnal frequency), modified by its phase with the lesser S2 tide. Out of phase is called “neap”, in phase is called “spring” and these alternate roughly every week. This is further modulated by apo/perigee, and then by ap/perihelion. The greatest Spring tide would occur if perihelion were to occur at an equinox (not for 5000 years or so) and perigee. These latter factors can be overwhelmed by local weather; atmospheric pressure bulges and winds.

Mercury makes a poor, shallow morning apparition this month. He skulks well below an already low ecliptic for his elongation.

Venus stands farther afield the Sun, and much less south of the morning ecliptic than Mercury. All month she will be easily mistaken as a distant airplane in the east before dawn.

Sun passes over Spring Valley 3 minutes 49 seconds before it reaches the time zone meridian of 75W. A lesser peak of the equation of time (published for the time zone meridian) renders clocks 3 minutes 41 seconds slow on the 13th this month. The two effects will make sundials agree with clocks at the middle of this month – excepting the silly discrepancy of the DST hour.

Mars is dimmer and to the right of Aldebaran, barely discernible as evening darkens in the early part of this month. Aldebaran subsequently drops from view much more quickly than Mars, overtaken by the Sun by Month’s end. Mars is not overtaken (conjunct) until July 27th – but is also un-viewable long before then.

Jupiter is now past opposition but also is more dominant in the evening since he is appearing higher as night falls. On the 1st he is 30 degrees in the SE at Nautical Twilight. On the 31st he is 45 degrees and South (culminating) at Nautical Twilight.

Saturn still rises very late and low – is really only noticeable to very early risers. He is quietly preparing for his opposition in June – but due to the wintry region he occupies, this will mostly be obscured by foliage and other ground clutter.

Star Calendar Days

1      Sunrise/set in Spring Valley at 5:59/19:53 (13h54m daylight)

        May Day (Beltane) celebrates beginning of cross-quarter Summer

        Mars, Sun and Saturn are in syzygy (fall on a line in space)

 2     Mercury is stationary to stars, now moves in normal (leftwards) motion

 3     Moon to right of Regulus, South as evening darkens

 4     Moon to left of Regulus, South as evening darkens

 5     Martian equinox, Spring for northern half.

 7     Moon beside Jupiter and above Spica in SSE as evening darkens

10     Full Milk Moon at 5:42PM, is apogee and in Libra

13     Equation of time makes SV sundials agree with clocks today

17     Mercury at largest (but shallow) angle from Sun for this appearance

22     Moon and Venus a fetching pair for early risers, East at 4:30AM

25     New Moon and Perigee, large amplitude Spring Tide

27      Mars below and to right of Moon shortly after 9PM WNW

30-31 Moon passes Regulus – look West each night around 10PM

31       Sunrise/set in Spring Valley at 5:26/20:22 (14h56m daylight)

Star Calendar – April 2017

Star Calendar

April 2017

Star C alendar Planets:

Moon and Sun balance on either side of the solstice point on the 7th. They rise and set at the same point on the horizon on that day and make the same path across the sky. One might observe the pair at 4:45PM and imagine the height of summer between them.

Mercury begins the month at greatest elongation, bright and decently visible just after 8:PM or so. He is hasty to depart though, and crosses the near-side of the Sun on the 20th.

Venus is already visible in the morning and will be stationary to the stars by the 12th. She is very tall, waxing less slender and will present a maximally brilliant dawn beacon by the end of the month.

Sun rises/sets steadily more north of east/west and adds an hour and a quarter of daylight over the course of this month.

Mars is seen low in the West at about 7:30 as the month begins and lower and later as the month progresses. Mars and Aldebaran (higher and to the left) look very similar these days. On the evening of the 28th the Moon, Aldebaran and Mars will shine together WNW at about 7:45PM.

Jupiter reaches opposition on the 7th. He is now brightest and closest for the year and is in the middle of his period of backward movement near Spica. Look for the Moon in the mix on the 10th.

Saturn is seen culminating in the early morning and stops in the steam (Milky Way) of the Teapot (Sagittarius) on the 6th to begin this year’s loop.

Star Calendar Days:

  1      Sunrise/set in Spring Valley at 6:39/19:21 (12h42m daylight)

          Day number 91; ¼ of the year has passed

          Mercury shining in low West 8:PM, sets at 9:PM

          Moon in horns of Taurus in evening, West

  6      Saturn stationary, begins retrograde loop at spout of Teapot

          Moon passes close to Regulus during this night

  7      Jupiter at opposition, brightest and nearest for the year

  9      Mercury stationary, then retrograde to stars, already retreating Sunwards

10      Moon clusters with bright Jupiter and Spica, ESE in evening

10-11 Full Pink Moon at 2:08AM  (leaf buds are pink)

11      Passover begins

12      Venus stationary, to direct motion

16      Moon with Saturn in south at 5:30AM

          Easter

20      Mercury, so recently visible, at inferior conjunction

22-23 Moon and Venus present the same phase, East at 5:30AM, use binoculars

26      Venus most brilliant for this appearance

28      Moon strikes a pose with Aldebaran and Mars, around 9:PM, West

30      Sunrise/set in Spring Valley at 5:55/19:52 (13h57m daylight)

          More than 2 ½ hours additional daylight since March 1st

          Midway from equinox to solstice, and about 1/3 of year has passed

          Venus covers greatest sky area for this appearance

Star Calendar – March 2017

Star Calendar

March 2017

 

Star Calendar Planets:

Moon cycles determine, or play a role in, some calendars such as the Islamic and Hebrew. The Islamic year is strictly lunar while the Hebrew is a hybrid luni-solar that inserts extra months so that the seasons don’t drift too far. The Hebrew year begins with Nissan. It commemorates the emancipation of the Jewish people from bondage in Egypt (Exodus) and Passover (whilst Rosh Hashanah commemorates the birth of the World). The Crucifixion is recorded in relationship to Passover and Easter is placed in such a way as to respect this correspondence. This year Nissan begins at sundown on the 27th of March, 15 Nissan (beginning of Passover) on the evening of April 11, and Easter on April 12. This year both Western and Eastern traditions correspond to the same day.

Mercury crosses the far side of the Sun and then appears already on the 18th next to Venus in evening.

Venus is now nearer to Earth than to the Sun as she streaks from evening to morning. On the 25th Venus is more than twice as far from the Sun than from the Earth – the ratio being just about 5:2. Venus begins the month stationary to the stars, then rapidly departs and crosses the nearside of the Sun by the 25th. She will be seen in the pre-dawn east already in early April.

Sun is rapidly increasing its presence in the sky by adding almost 3 minutes of daylight to each day. Of course, as we gain an abundance of daylight – the Govt. must naturally order us to start “saving” it.

Mars is seen to the right of the crescent Moon on the evenings of the 1st and again on the 30th.

Jupiter begins March near Spica and we can watch him move, retrograde, back away from Spica as the month proceeds. The pair rises about two hours after sunset and is joined by the Moon on the 14th.

Saturn slows his slow shuffle – that is so slow that he lingers in each seasonal quarter of the sky for over 7 years.

Star Calendar Days:

1 Sunrise/set in Spring Valley at 6:30/17:47 (11h17m daylight)
    Day number 60; about 1/6 of the year has passed
    Moon to left of Mars at dusk in west
    Moon and Venus in same crescent phase (use binoculars) as they set

2 Venus stationary to stars, prepares for dash across near side of Sun (25th)

4 Moon approaches to very near Aldebaran, dusk to midnight

6 Mercury crosses the far side of the Sun; superior conjunction

10 Moon moves away from Regulus this evening

11-12 Absent an Executive Order from the President, American clocks shift forward
      Full Crow, Worm, or Sap Moon at 10:54AM Daylight Shifted Time

14 Day 73 number; about 1/5 of the year has passed – and it’s Pi-day too
      Moon, Jupiter and Spica appear together at 10:PM ESE

16-17 Etymological equinox = equal night; Sun is down 12 hours and zero minutes

18- Mercury appears to left of Venus in gloaming – perfect Western view at 8:PM

20 Astronomical equinox at 6:29 – Sun’s center crosses celestial equator
      Sunrise/set in Spring Valley at 6:59/19:09 (12h10m daylight)
      Moon above Saturn around 6:AM, they culminate at sunrise

25 Venus streaks across near side of Sun; inferior conjunction

27-28 New Moon begins Hebrew month of Nisan – that places Passover and Easter

31 Sunrise/set in Spring Valley at 6:41/19:20 (12h39m daylight)
      Day number 90; nearly ¼ of the year has passed
      Enjoying the additional 1 hour and 22 minutes of daylight?

Star Calendar – November 2016

Star Calendar

November 2016

Star Calendar Planets:

Moon draws exceptionally near this month (nearest in 30 years) while also Full as it sets on the morning of the 14th.

Mercury peaks into the evening sky as Saturn departs. Around the 23rd will be the first chance to see Mercury – and the last for Saturn for this apparition. Failing that, try again on the 30th when the razor-thin new crescent Moon may serve as a guide. If that fails too, try under the Moon on Dec. 1st.

Venus crosses the Teapot (or Sagittarius) while making her oh-so-slow ascent into evening.

Sun is furthest ahead of Greenwich Time for the year on the 2nd, but is still behind our clocks – until we finally fall back from Daylight-distortion Time on the 6th.

Mars is beyond culmination (its highest altitude for that day, in South) at sunset now, and is being slowly overtaken by the Sun – but Mars will appear higher in the sky on successive nights at a given time because it is progressing beyond the midwinter portion of the ecliptic – and the ecliptic is more steeply inclined to the horizon at sunset. A little counter-intuitive.

Jupiter also appears higher every morning, but simply because the Sun is leaving it behind. The morning ecliptic is still very steep (October mornings are like March evenings in this respect) and will gradually drop through January. Jupiter gets a visit from the Moon on mornings of the 24-25th.

Saturn settles into the sunset, next to appear some morning after midwinter.

Star Calendar Days:

  1      Sunrise/sunset in Spring Valley at 7:28/17:51 (10h23m daylight)

  1, 2   Venus, Saturn & Moon over Antares in SW at 6:45PM

  2      Equation of time maximum for year 16m26s

  3      Moon above Venus in SW at 7:PM

  6      Mornings brighten after U.S. clocks move back to Standard Time

          Moon above Mars South and West in evening

  9      God help us from our dis-aster (bad star) – whichever way it went

11      Martinmas – begins cross-quarter winter

13-14 Super Duper Moon: Full Frost Moon 8:52 AM at extreme perigee

16      Moon rises ENE on the summer colure at 7PM

17      Leonids peak in poor viewing conditions (too much Moon, too nearby)

20-21 Moon passes Regulus without occultation (was one last time)

24      Mercury may just be visible with Saturn at 5:PM with perfect WSW horizon

25      Moon and Jupiter above Spica in SE at 6:AM

28      Solstice on Mars, mid-winter for northern half

30      Mercury to left of Hilal Moon in WSW at 5:PM

          Sunrise/sunset in Spring Valley at 7:01/16:28 (9h27m daylight)

Star Calendar – August 2016

Star Calendar

August 2016

Star Calendar Planets:

Moon passes just out of reach of Earth’s sizable shadow on the 18th as it sets at dawn. It is very close to being, or not being, a technical penumbral encounter – but nothing observable will occur. Some eclipse tables will list this event, others will not. Both are correct! An annular solar eclipse will cross Africa and Madagascar on September 1st when the Moon’s shadow doesn’t quite reach the Earth.

Mercury makes its widest excursion from the Sun this month but does so doubly disadvantaged from our point of view. Firstly the ecliptic is dropping dramatically to the left of the Sun (aka the coming decent into fall) and secondly Mercury is passing rather south of the ecliptic line. At greatest elongation on the 27th, Jupiter and Venus have a lesser elongation but stand higher than Mercury in the evening – as they are north of the ecliptic just now.

Venus sets at 9:PM on the 1st and then about one minute earlier each day thereafter – but the Sun sets even earlier, gaining about a minute and 21 seconds each day – so Venus is a little higher each evening twilight relative to sunset but is lower each evening relative to the clock. During this month she will pass Regulus, Jupiter and Mercury.

Sun stands in the middle of Cancer as the month begins, crosses into astronomical Leo on the 9th and reaches Regulus on the 21st. If you recall where Jupiter stood (beneath the belly of Leo) at the extremity of his last loop (stationary on May 9), the Sun will reach that spot on September 5th.

Mars will make a striking equilateral triangle with Saturn and Antares, in the south on the 11th, but the Moon standing directly above him will make a distracting lozenge – or possibly blot out Antares. So perhaps on any other day it is a good time to contrast Mars with Antares as they approach one another. They are conjunct on the 23rd/24th.

Jupiter is in direct motion, meaning that he appears further leftwards each day against the stars. The Sun and Moon epitomize this motion and the planets execute variations and contrasts to this theme. Venus is moving more quickly than the Sun, Jupiter more slowly – and Venus will catch up on the 27th for a very close and very bright conjunction. That would be a night to find a 10 to 30 power telescope with either not too large an aperture or fitted with some filters, for Venus will be so close that she’ll mingle amongst the Moons of Jupiter. The pair will be low and due West at 8:15 PM at the very beginning of Nautical Twilight conditions. Find a good spot ahead of time.

Saturn is within the meridia of Scorpius, (though astronomically in Ophiucus) and stands above (north of) Antares. Mars will cut between the two on the 23rd/24th.

Perseid meteors statistically peak mid-month, but the gibbous Moon presents a liability then. There have been known to be earlier outbursts however, so gazing Perseus/Cassiopeia-wards earlier in the month may reward. The Aurigids peak in better conditions at the end of the month – but are above the horizon in the pre-dawn hours – raying from above Orion’s shoulder.

Star Calendar Days:

  1      Sunrise/sunset in Spring Valley at 5:52/20:12 (14h20m daylight)

  2      New Moon

  4      Mercury to right of young Moon, 8:45PM in West

          Also, lower to right, Venus

  5      Venus and Regulus conjunct in evening, latter probably washed out by sunset

  6      Moon just beneath Jupiter, setting by 9:30 PM in West

11      Moon, Mars, Antares, Saturn make a lozenge in SSW at 9:PM

12      Perseids peak – by statistics of the past

13      Saturn stationary to direct motion

16      Mercury at largest (but very low) angle from Sun for this appearance, 27 degrees

18      Full Red Moon (5:27 AM) sets in slight penumbral eclipse in early morning

23-25 Mars passes between Saturn and Antares, SSW in evening

27      Venus and Jupiter pass very close in West as Sun sets – should be quite bright

30      Mercury stationary to retrograde

31      Sunrise/sunset in Spring Valley at 6:22/19:30 (13h8m daylight)

Star Calendar – July 2016

Star Calendar

July 2016

Star Calendar Planets:

Moon will show only 1/7 of her fullness on the 7th of the 7th month. 7/7 is the date of the oriental star festival called Tanabata – when two lovers (stars Vega and Altair), separated by a river (the Milky Way), may be allowed to meet if the river vanishes. But that is unlikely this year since the Moon is too small (dim) to vanquish the river. However, terrestrial lights may very well do the job instead; Orihime and Hikoboshi are probably big fans of Light Pollution.

Mercury crosses behind the Sun on the 6th-7th and might just be seen at the end of the month in the evening. On the 30th, with a good view to the west, Venus should shine out by around 8:30 PM. Following her descent, Mercury should appear to her left, and Regulus might just be made out very close beneath Mercury – try binoculars. That will be the nearest planet-to-bright-star conjunction for the year.

Venus should be visible (west) in bright evening twilight after mid-month or so, but she sets by around 9:PM. Mercury will pass close by on the 16th, but the sky will likely be too bright to see him. Again, one might try binoculars.

Sun is at its highest on the 4th – in the sense of distance-from-the-ground or Aphelion. Might the Earth be deemed most independent then? Proximity of the Sun slightly exaggerates the Winter/Summer of the southern hemisphere – but tempers those seasons in the north. Ocean is preponderate in the south – and it tends to subdue the seasons by great thermal mass and circulation – while land masses respond more quickly to the solar input. At present the apsides rather subdue climate change – with a residual net warming; the last ice age is still finishing up – but as the apsides shift (over centuries), a net cooling will again glaciate the north. The effect of apsides is smallish on the earth – but is large on eccentric Mars.

Mars, still brighter than any star, now culminates (is highest, in the south) as dark falls. He shone like a flying cinder during our St. John’s bonfire.

Jupiter is brighter than Mars – but is lower and further west each day when he appears. He entertains the Moon on the 8th and 9th.

Saturn makes a huge triangle with equal-brilliance stars Arcturus and Vega (the latter is slightly brighter). Saturn will gradually be higher and more southerly at first appearance each evening as the month progresses. In August he will appear in a fashion similar (in position) to that of Mars this month.

Star Calendar Days:

  1      Sunrise/sunset in Spring Valley at 5:28/20:32 (15h4m daylight)

  4      Aphelion at noon – Sun is 3% farther than in January

          Sun, Moon, Venus and Mercury between the knees of Gemini

          Equinox on Mars, autumnal for northern part

  7      Mercury at superior conjunction – crosses behind Sun

          Moon beneath Regulus after sundown

          Tanabata – oriental star festival of Orihime (Vega) and Hikoboshi (Altair)

8-9     Moon near Jupiter in West at dusk

11      Moon between Mars and Jupiter, and beside Spica, SW in evening

14      Moon, Mars, Antares and Saturn make an oblong in South at 10:PM

16      Moon, Saturn and Mars make a line over Antares at 10:PM

19      Full Thunder or Hay Moon at 6:57PM

30      Perhaps find Mercury near dimmer Regulus as Venus sets, W around 9:PM

31      Sunrise/sunset in Spring Valley at 5:51/20:13 (14h22m daylight)

Star Calendar – June 2016

Star Calendar

June 2016

Star Calendar Planets:

Moon crosses the seasonal colures (meridians of solstices and equinoxes) every month. This month Sun and Moon cross opposite colures on the same day. Just as the length of daylight changes with the seasons – so does the time of Moon-Up change rapidly through the month. For this month, Moon crosses the colures of Summer, Fall, Winter and Spring respectively on the: 4th at 23:32, 12th at 20:00, 20th at 08:26 and 27th at 00:25. The duration of Moon-Up on those days is: 14h35m, 12h29m, 10h4m and 12h26m. The extreme are somewhat subdued because the inclination of the Moon’s path with respect to the celestial equator is currently less than the Sun’s inclination; in a few years’ time the lunar seasons will be more exaggerated than the Sun’s.

Mercury may come into view mid-month – low in the ENE at around 4:30AM. I was not able to do an elaborate setup to view last month’s transit – but twice thought I might have seen it through welder’s glass. A lot of folks took nice photos though.

Venus crosses the backside of the Sun on the 6th. We may expect to see her next in mid-July.

Sun now occupies the sky for a pretty steady 15 hours a day. Note below the subtle differences between earliest/longest/latest dates and times. This year the solstice occurs on the same day as Full Moon – which means that the Sun is making a long summer crossing while the Moon takes a short wintery walk – rising very south-of-east and culminating very low in the sky.

Mars continues to be in our face this month but his rise-time advances more slowly as he approaches the end of his loop on the 30th. He is receding, first slowly, then rapidly, and will be fading noticeably as July approaches. On the 1st of this month he shines at magnitude -2.1 (brighter than Jupiter) and by July at -1.4 (rather like a red Sirius).

Jupiter still dominates the SW as darkness falls – but Mars holds sway in the SE.

Saturn varies less in brightness and follows Mars across the sky – trailing him by about an hour. Saturn is as bright now as the brightest summer star (Vega), but, appearing much lower, tends to draw less notice perhaps.

Star Calendar Days:

1      Sunrise/sunset in Spring Valley at 5:26/20:23 (14h57m daylight)

3      Saturn in opposition (exactly opposite the Sun in our sky)

4      Jupiter is at eastern quadrature (exactly ¼ of the sky from the Sun)

Moon occults Aldebaran during the day (again in October at night)

5      Mercury at largest angle from Sun in morning sky

6      Venus at superior conjunction (crosses behind Sun)

8      Moon to left of Castor and Pollux (Gemini) at 9:30PM

10      Moon between Regulus and Jupiter tonight

13      Sun, Mars, and Saturn fall on a line in space; Martian opposition of Saturn

14      Sunrise earliest in Spring Valley, at 5:23AM

14-15 Moon above Spica and between Mars and Jupiter

17      Moon, Mars, Antares and Saturn make a lozenge, culminating as darkness falls

20      Sunrise/sunset in Spring Valley at 5:24/20:32 (15h8m daylight)

Full Strawberry Moon 7:02AM

Solstice at 6:34PM EDT

23-24 St. John’s Eve/Day, traditional mid-summer

27      Sunset latest in Spring Valley, at 8:33PM

30      Sunrise/sunset in Spring Valley at 5:27/20:33 (15h6m daylight)

Mars stationary to stars, end of retrograde loop, begins normal motion

Star Calendar – May, 2016

Star Calendar

May, 2016

Star Calendar Planets:

Moon is Full three, or sometimes four, times in a season but the names that various cultures have assigned to characterize the circumstances around various full moons of the year generally number 12 – leaving the occasional unnamed one. Similarly the Hebrew luni-solar calendar has 12 months – but needs to insert an inter-calary month about every three years to maintain its relationship to the solar year. In each case the adjustment occurs 7 times in 19 years – the extra full moon is called Blue and the extra Hebrew month is called second Adar. This month’s full Moon coincides with the opposition of Mars – and the latter will shine in the very spot towards which falls the shadow of the Earth – so on the night of the 21-22nd one can easily see just how far the moon is from being eclipsed.

Mercury promises to be visible in broad daylight on the 9th. Inferior conjunction will cut right across the face of the Sun, beginning somewhat after sunrise, midway around 11 and leaving in mid-afternoon. One can observe this with a camera obscura arrangement that projects and enlarges the disk of the sun onto a screen. I might cover a south or SE-facing window and allow a pinhole of light through a piece of aluminum foil to cast onto a sheet of white cardboard. Such a transit of Mercury last occurred ten years ago – but these are far less rare than transits of Venus – which I will never see again.

Venus is lost in morning limelight as she heads backstage for some future showing in evening attire.

Sun is midway from equinox to solstice on the 1st. Astronomically this marks the beginning of Summer, the solstice being regarded as mid-summer. The days are now getting longer much more slowly – by about one minute a day as the month opens and only 30 seconds a day as the month ends.

Mars makes a large retrograde stroke and rises dramatically earlier over the course of this and next month. He breaks the horizon at about 9 PM on the 1st and already at 6:18 by the 31st.  This opposition is the nearest for Mars since the superlative one of ten years ago. But, due to Mar’s high degree of ellipticity, he will continue to draw nearer for another week after opposition, then being twice as near to us as is the Sun (.5AU).

Jupiter finally diminishes perceptibly from its late brilliance but still dominates the evening sky in the south. Mars will match magnitude during its opposition- but rises later and culminates much lower – achieving only the altitude of the Sun at mid-winter.

Saturn is also in a retrograde loop, one much smaller than Mars’, and rises just under an hour later. Saturn is then seen to be about as bright as Arcturus – but shining with a steady light compared to the latter’s yellow-green scintillation. Saturn will reach opposition on June 3rd.

Star Calendar Days:

  1      Sunrise/sunset in Spring Valley at 5:53/19:54 (14h1m daylight)

          First day of cross-quarter-wise summer, Beltane

  6      New Moon 15 hours after perigee, again large spring tides

  8      Moon to right of Betelgeuse and above Aldebaran, WNW around 9:PM

  9      Mercury crosses face of Sun (transit) begin 7:12-max 11:-ending 2:40

          Jupiter stationary to direct motion, ends it’s loop for this year

13      Moon next to Regulus, SW as dark falls

14      Moon next to Jupiter, SSW as dark falls

18      Moon beside Spica, SE as dark falls

21      Full Blue Moon at 17:14 (This season has 4 Full Moons, the 3rd is “Blue”

          Mars rises (in the exact direction of Earth’s shadow) beside the Moon, ESE 8:30PM

          Mercury stationary to direct (leftwards motion against stars)

22      Mars in opposition 7:AM, 14 hours after Full Moon

          Moon rises to left of Saturn, SE at 10:PM

30      Mars is nearest Earth, half as distant as is the Sun

31      Sunrise/sunset in Spring Valley at 5:26/20:22 (14h56m daylight)

Star Calendar – April 2016

Star Calendar

April 2016

Star Calendar Planets:

Moon is very dynamic and has several motions of similar mode. A Frenchman sewed photographs of sequential Full Moons together into an animated GIF that shows very nicely the net effect of the various librations – the nodding and swaying face and changes in proximity in a kind of slow stroboscopic form. The next-to nearest perigee for this year coincides pretty closely to New Moon this month – the waters will respond. Of note; the center of mass of the Moon is well displaced from its geometrical center. This lopsidedness is probably why we see only one side of the Moon – its center of mass prefers to be toward the earth.

Mercury is an evening star all this month. With a good view to just North of West one might find him to the right of a thin Moon around 8:15 PM on the 8th. Thereafter he will be higher until the 18th, then seen below the Pleiades as late as around 9PM.

Venus is now difficult to view in the morning. With a very good East horizon try to look to the left of the Moon on the 4th at 6:10 AM – Venus will next appear some evening in latter July.

Sun is not a point of light – rather a disk of ½ degree or 1/720th the circumference of the sky. Due only to this the Sun is visible above the horizon to slightly more than ½ of the planet at a time. In addition, the medium of air, increasing in density from empty space, bends the visibility of the Sun a further half-degree or so beyond the geometric-tangent horizon, trebling the effect. At any moment, roughly 50.4% of the Earth is in daylight. This has to do with why day and night are not of equal length on the equinox.

Mars approaches headlong this month and brightens dramatically. He does so near Antares (similar color but much dimmer) and Saturn, to his left. Recall that Mars and Saturn were of equal brilliance in mid-February – now look at the difference! Mars’ opposition is coming May 22nd. They are visible, low and southerly, between about 11PM and 5:30AM.

Jupiter appears much the same as last month, repeating a prominent pairing with the Moon on the night of the 17th.

Saturn makes a nice contrast to Mars and will be in its opposition on June 3rd, only 12 days after Mars’.

Star Calendar Days:

  1      Sunrise/sunset in Spring Valley at 6:39/19:22 EDT (12h43m daylight)

  6      Moon and Venus rise together – only with a perfect view east, at 5-5:10AM

  7      New Moon and very-near perigee only 6 ½ hours apart – spring tides

  8      Moon and Mercury set together – only with a perfect view west, at 8-8:30PM

10      Aldebaran emerges from occultation by Moon as they set; West, 8-11PM

12      Moon passes Alhena (foot of Gemini) WSW in evening

14      Moon makes a line with Pollux and Castor (heads of Gemini) SW in evening

16-17 Moon passes Regulus

17      Mars stationary to retrograde, brightening most rapidly now

17-18 Moon and Jupiter make a bright couple all night (like last month)

18      Mercury at largest angle from evening Sun for this appearance

20      Mars and Saturn nearest (no conjunction), visible SW11:30PM to SSW5:30AM

21      Moon setting with Spica WSW at 5:30AM

21-22 Full Sprouting Moon at 1:24 AM

23      Passover begins, the 15th of Nissan

24      Moon, Mars, Saturn & Antares rising together SE at 11:30PM

26      Mars, the brighter, nearest to Antares – of similar color; culminate S at 3:AM

29      Mercury stationary, to retrograde

30      Sunrise/sunset in Spring Valley at 5:55/19:53 (13h58m daylight)

 

1/3 of 2016 has passed; also midway from Spring equinox to summer solstice