The Really Old Moon
December 28, 2016
The extremely thin sliver
Crescent Moon, 0.8% illuminated, had
reached 2° altitude when this image was captured at 6:44 am
December 28, 2016, 15 minutes after moonrise at
6:29 am, from the old Mart site in Pennsauken, NJ.
The moon was only 19 hr 09 min prior to new on December 29 at 1:53 am, and
28.976 days old since the previous new moon on November 29 at 7:18 am.
Solar elongation was 9°14'. Taken
with a Canon 6D digital SLR
camera and a Canon 400 mm f/5.6L telephoto lens on a fixed tripod (then cropped
to 32% of the original size for a field about 1.7° wide x 1.1° high).
Exposed 1/30 second at f/5.6, ISO 3200. Mouseover for label. Note: The
tree in this picture is the same one that stands above the others to the
right of the pair of utility towers in the pictures of the old crescent
moon on November 28 shown further down this page. It's not pictured
here, but the planet Saturn was spotted
just below the bottom edge of the cloud mass at 6:25 am, which soon
covered it. Saturn was at solar conjunction on December 10, 2016.
The thin crescent was
initially spotted visually at 6:40 am with 16x70 binoculars when it was
near the upper right of the tree, then followed until 6:45 am when it
was lost behind the bottom edge of the cloud mass that had descended to
the utility wire just above
the thin crescent in this picture. So visually, the moon was last seen
when it was 19 hr 08 min from new,
which is my personal record for the minimum time span between the moment
of new and the sighting of the thin crescent (either before or after
new). My previous record was 20 hr 01 min old for the young moon on February 3, 2011.
What was unusual compared
to my experience recently was the cloud situation. Frequently, I
would find that when leaving my home for the Mart site before sunrise,
the sky was generally clear (often, quite clear), but upon arrival at
the Mart, the band of sky above eastern horizon would be cloudy,
obscuring the object that I had hoped to observe. This time, the sky was
mostly cloudy, but it was relatively clear along the horizon, which
provided a narrow window to see this thin crescent. I'm now hoping for
clear skies on Thursday evening, December 29, for an opportunity to see
the even thinner crescent (0.5% illuminated) of the young moon, roughly 15 hours after new (for a
combined span from before new moon to after new moon of a little more than 34 hours). Even with
excellent transparency, it will be a very challenging observation.
Update December 29: It was cloudy for most of
the day, with periods of rain, but after 4 pm, there appeared to be
some clearing above the western horizon, so I headed to the Maple Shade,
NJ, baseball field complex. There was an approximate 5° high
cloud-free band along the horizon (extending at most a few degrees above
the distant tree tops), but the transparency in that band seemed less than
ideal. In any case, I looked for the thin crescent with 16x70 binoculars
from about 4:50 pm (7 minutes after sunset) to 5:11 pm EST (when the moon
was at 2° altitude, 15 minutes before moonset). Not surprisingly, I did
not detect even a hint of the thin crescent. Tomorrow evening, December
30, the moon will be about 39 hours old, 3% illuminated and 12° altitude
at at 5 pm, so it will still be an attractive sight.
The Moon Occults Aldebaran
December 12, 2016
December 12, 2016, the nearly-full moon (full on
December 13th at 7:06 pm EST) would occult the first-magnitude star
Aldebaran, in Taurus,
about 11:11 pm EST in the Philadelphia area. Since the moon was
travelling eastwards through the Hyades star cluster earlier in the
evening on its way to Aldebaran, several less-bright stars would be
occulted beforehand too. Notably, the naked-eye double, Theta 1 & 2
Tauri (magnitude 3.8 and 3.4 respectively). I stepped out front of my
Maple Shade, NJ, home with 16x70 binoculars and saw Theta 1 disappear at
7:21 pm and Theta 2 at 7:32 pm. Aldebaran was easily visible with
unaided eyes a couple of degrees east of the moon. I went back out at
8:10 pm to catch the reappearance of the Thetas and the disappearance of
magnitude 4.8 HD 28527, but I was already too late for Theta 2, and I
never did see Theta 1 and HD 28527 by time I returned inside at 8:20 pm
because thin clouds covered the sky around the moon. I was hoping to see
the shrinking gap from the moon to Aldebaran, but the latter was no longer visible with
unaided eyes, although it was still readily apparent with the 16x70s.
Finally, I went out to the
back yard around 10:30 pm to set up my camera for the Aldebaran occultation,
but was I greeted by even thicker clouds that produced a distinct
22° halo around the moon as pictured above
(the moon is greatly overexposed to show the halo). Taken at 10:34 pm with a Canon
6D digital SLR camera (on a fixed tripod) and a Sigma 20 mm f/1.4 Art
lens. Exposed 1/30 second at f/2.2, ISO 12,800. Orion is at the 7 to 8
o'clock position near the outer edge of the halo, and Capella is the
bright star perpendicular to the 11 o'clock position on the halo (mouseover
for labels). Using 10x50 binoculars,
Aldebaran was varyingly visible close to the moon (sometimes invisible) as the density of
passing clouds varied.
I went back in the house
briefly just before 11 pm, and with pessimism, stepped back out at 11:08
pm. However, I was astonished to find the moon in a clear patch of sky.
I could see Aldebaran close to the moon's limb with 10x50 binoculars,
and it seemed to disappear into a crater about 11:12 pm (as best as I
could tell by trying to read my wristwatch in the dark). I also took a
few quick snapshots before picking up the binoculars. The one above
being the next-to-last, which shows a narrow gap between Aldebaran and
the moon at the approximate
9 o'clock position. It was taken at 11:10:28 pm (the camera's clock is
set by its internal GPS; the very last image 14 seconds later looked a bit blurred,
as if from vibration). Taken with a Canon 7D Mk II digital SLR camera
plus a Kenko
1.4x teleconverter and a
Canon 400 mm f/5.6L telephoto lens (on a fixed tripod) for an effective
focal length of 560 mm (then cropped).
Exposed 1/20 second at f/8, ISO 1600. The moon, 20 hours before new and
99% illuminated, was greatly overexposed
so that Aldebaran would be visible, but note that the proceeding limb
(on the left) is a little craggy from craters at the terminator (mouseover for labels).
Mercury Elongations - 2016 Completed
six elongations in 2016.
The initial sighting for each of these is tabulated below:
January 28, 6:30 am EST
RR Tracks, Maple Shade, NJ
February 6, western
April 3, 7:49 pm EDT
Coyle Field, Woodland Twp, NJ
April 18, eastern
June 6, 4:44 am EDT
Old Mart Site, Pennsauken, NJ
June 5, western
July 11, 8:39 pm EDT
Swede Run, Moorestown, NJ
August 16, eastern
September 22, 5:58 am EDT
Old Mart Site, Pennsauken, NJ
September 28, western
November 18, 4:59 pm EDT
Baseball Fields, Maple Shade, NJ
December 10, eastern
Click here for the sighting
details of each elongation for 2016 (the final individual sighting
was on December 15th). The current sighting streak at this point is 38 elongations in a row, starting in January 2011, which
complete calendar years of six or seven elongations each (click
here for sightings from last year's elongations). This demonstrates that locating and seeing
Mercury is not nearly as difficult as many suppose. It just takes some
planning and a little effort.
The Waxing Crescent Moon
December 5, 2016
The 35% illuminated waxing
Crescent Moon was captured
several times on
December 5, 2016, as shown in these three images.
Although they look largely the same, they are in fact three different images. All were taken with a
Canon EOS 7D Mk II digital SLR camera and a Canon 400 mm f/5.6L
telephoto lens on a fixed tripod. From left to right, the first image
was captured with the telephoto lens alone, the second with telephoto
lens and a Kenko 1.4x teleconverter and the third had a Kenko 2x teleconverter.
Each was cropped to similarly fit a 4:3 ratio frame, then resized and
resampled to the same final size (350 pixels wide above, 1200 pixels
wide for the
larger versions on this page). Exposure details are also noted on
that page. Even when looking at the larger versions, I don't see one
that is clearly the best.
The Old Crescent Moon
November 28, 2016
The view looking a bit
south of east from the old Mart site in Pennsauken, NJ, at 5:54 am
EST on Monday,
November 28, 2016, one minute before the
crescent moon would rise, and 65 minutes
before sunrise at 7:00 am. This site is little more than a mile from the
intersection of 40°N-75°W, and the light just above the tree tops
between the two power transmission towers is at 111° azimuth.
Two stars are visible,
each at 7° altitude, Zubeneschamali (Beta Librae) in the upper-left
corner, and in the upper right corner, Zubenelgenubi (AlphaČ Librae,
plus its fainter companion, Alphač Librae, 4 arc minutes above it).
Zubeneschamali served as a guide for locating the not-yet-visible moon,
which would be 40 arc minutes to the right of a perpendicular line from
the horizon to the star. Taken with a Canon 6D digital SLR camera plus a
Kenko 1.4x teleconverter and a Canon 100 mm f/2.8L macro lens on a fixed
tripod (then cropped to 85% of then original size for a field about
12.4° wide x 8.3° high). Exposed 2 seconds at f/5.6, ISO 1600.
Mouseover for labels.
When it rose at 5:55 am,
the moon was 28.72 days old with respect to the previous new moon on
October 30, 2016, at 1:38 pm EDT, and 25 hr 23 min before the next new
moon on November 29, 2016, at 7:18 am EST. If spotted after sunset on
Wednesday evening, November 30th, the young crescent moon will be about
34 hours old, so a combined
span of less than 60 hours between spotting the old and new moon is
possible. However, rainy weather on Wednesday evening precluded any
chance of seeing the young moon.
But... The new moon on
December 29, 2016, at 1:53 am EST offers a chance
for a really brief span between the before-new moon (roughly 19 hours on
December 28th) and the after-new moon (roughly 15.5 hours old on
December 29th) for a combined 34.5 hours. If the young moon is missed on
the 29th, the 30th offers an approximate 39.5-hour-old moon after
sunset, producing a total span of around 58.5 hours.
Crescent Moon was initially spotted with
10x50 binoculars, and this picture was captured, at 6:05 am
November 28, 2016, when the moon reached 1°30'
altitude 10 minutes after it rose at 5:55 am (note that altitude is
measured from the center of the moon, while moonrise/set, like
sunrise/set, is when the upper limb is at the horizon, all adjusted for
atmospheric refration). The thin crescent was first seen with
unaided eyes at 6:10 am. Taken with a Canon 6D digital SLR camera plus a Kenko 1.4x teleconverter and a Canon 100 mm f/2.8L macro lens on a fixed
tripod (then cropped to 71.5% of the original size for a field about
10.4° wide x 7.0° high). Exposed 1/15 second at f/4, ISO 12,800.
Mouseover for label.
Crescent Moon had reached 4°42' altitude
when this image was captured at 6:25 am
November 28, 2016, 30 minutes after moonrise.
Taken with a Canon 6D digital SLR camera plus a Kenko 1.4x teleconverter
and a Canon 400 mm f/5.6L telephoto lens on a fixed tripod (then cropped
to 85% of the original size for a field about 3.1° wide x 2.1° high).
Exposed 1/15 second at f/8, ISO 1600. Mouseover for label.
The last sighting with
unaided eyes was at 6:30 am. Note that the moon has moved from the
bottom-right of the left tower in the previous picture to the top-right
of the right tower here. It was last seen with 10x50 binoculars at 6:45
am, 15 minutes before sunrise, when it was 1.0% illuminated, 4°42'
altitude, 28.76 days old and 24 hr 33 min before new.
for some older images.