Media Combinations – Page 35 – Astronomy Sketch of the Day

A Mystery Wrapped in a Riddle Covered to the Brim in Lava

Wargentin and Environs
By Richard Handy

Immediately south west of Schickard near the South West limb, lies a crater that can truly be regarded as one of the Moon’s most unusual and enigmatic features. Eighty four kilometer Nectarian aged Wargentin is a cup filled to the brim with ancient mare lavas. Its relatively smooth and flat floor has a series of gently sloped branches from it’s central wrinkle ridge, yet beyond this gentle relief it is almost flush with the crater rim, creating a plateau fully 450 meters higher than the surrounding mare. The maria like surface shows significant albedo (shades of grey tone) differences. There is a coating of light material that appears in patches and sheets most probably of Orientale origin, the last remnants of the skirt of fluidized flow fronts settling out over this region.

There are a few smaller or partial versions of this “filled to the rim” crater phenomena on the lunar surface, however nothing of this size appears anywhere else on the Moon. What special conditions must be satisfied to allow for the creation of this bizarre lunar plateau? We can be assured that the inner crater walls did not have many faults or openings that would have allowed the mare lavas to escape. A close look at the exterior wall shows that it remains relatively free of large secondaries or craterlets. This obvious lack of wall destruction certainly must have played a role in the continued embayment of the lavas over time.

An element that may have been a factor was that Wargentin appears have excavated a deep crater in pre-existing mare units. Hypothetically these denser basalt rims could more effectively embay lavas than the rims of craters in plains or highland areas because of their more compact stratification. Rim material would therefore be much more likely to hold the magma within the inner walls, as the floor slowly crept higher and higher on each new inundation.

The third element is perhaps the least well understood. How did its magma channels, cracks or fissures deep beneath the crater bowl itself, feed this unique crater? In other words what kind of plumbing was required to allow this “bathtub” of a crater to fill to overflowing? There must be a reason that the crater continued to fill up over the millions of years required to lay down such a volume of lava. Or alternately did it fill up, at least partially, in a relatively short time span of tens of thousands of years while still a young feature, perhaps after the impact penetrated into liquid magma filled channels or chambers? Nearby Schickard shows evidence that some mare lava flooding occurred after the dusting by the Orientale impact and therefore argues for a gradual buildup over many tens of millions of years.

Lunar geological research will undoubtedly uncover some of the reasons this remarkable and puzzling feature exists, yet its enigmatic and singular nature may well have to wait for a more sophisticated understanding of the early lunar crust and mantle.

Sketch details

Subject: Wargentin and environs
Date: 3-2-07 (UT) Julian date: 3-1-07
Session Start 6:32 UT End 8.00 UT
Seeing: Antoniadi II-III Weather clear
Lunation 1041, 12.51 days Phase: 20.1 deg Illumination 96.9%
Colongitude: 65.0 deg
Lib in Lat: -02 deg 19 min Lib. in Long: +4 deg 52 min
Telescope: Meade 12” SCT f/10
Meade Star diagonal
Binoviewer: W.O. Bino –P with 1.6X nosepiece
Eyepieces: 12.4 mm Meade Super Plossls
Magnification: 393X
Sketch medium: White Conte’ Crayon on black textured Strathmore paper
Sketch size: 18” x 24”

Pillars and Threads of Plasma

Solar Prominences and Filaments
By Erika Rix

Erika’s composite solar H-Alpha sketch from October 29, 2007, features prominences along the eastern limb as well as delicate filaments on the solar disc itself. Material used: black Strathmore Artagain paper with a combination of white Conte’ pencil for the brighter, more dramatic areas and white Prang pencil for the fainter areas.

Holmes in a Spin

Comet 17/P Holmes
28th October 2007
18:40 UT Mag 2
Reflector FL 1200mm/8mm eyepiece/150X Pastel/Conte/Black Paper

Here is my sketch from October 28th, I got going early to avoid the predicted cloud cover. I had a long look into the halo around the nucleus. The material emanating from the pin point center seemed to be heading in a more southerly direction than I had observed in previous evenings. I could see darker areas fanning in the opposite direction in the inner halo. A star was visible just inside the outer halo. Because I could see a star through the out gassing then it must be very thin? The star was visually similar in size to the comet nucleus but a little dimmer. Sometimes the coma seemed to momentarily have transparent spaces within it. I have not seen a star in the area of the dark spaces, I wonder if these spaces are filled with dust?

All this was visible even though there was a 17 day moon rising almost directly under the icy action.

Deirdre Kelleghan
President
Irish Astronomical Society 1937 – 2007
Public Relations Officer IFAS
http://www.deirdrekelleghan.com/
http://homepage.eircom.net/~irishas/index.htm
http://www.irishastronomy.org/

Walther’s Ray of Sunshine

Sunset Ray on the Floor of Walther

Crater Walther (formerly known as Walter) lies on the southern lunar highland’s great peninsula facing almost directly toward the earth. This is an ancient land, high, heavily bombarded and Walther is a Necterian age, 145 kilometer member. This walled-plain crater has tall terraced walls that tower 4 kilometers above the crater floor. The off center central peak stands 1.6 kilometers above the surrounding floor. The ancient rim is heavily cratered and has several incisura along its circumference created by impacts. Before sunset and at just the right time light penetrates through a notch in the western rim and sprays light across the floor to the central peak and several floor crater rims beyond in an eastward direction. The remainder of the floor is completely dark creating the frozen searchlight view that I attempted to capture in this sketch. West of the notched wall is crater Deslandres W with its large rim blocks which separates it from the hellplain, Deslandres to the west. Walther also has a sunrise ray that can be seen beyond first quarter at just the right time.

The following webpage gives the times of lunar ray events for craters including Walther. http://www.lunar-occultations.com/rlo/rays/rays.htm

Sketching:

For this sketch I used: black Strathmore 400 Artagain paper, 8”x 8”, white and black Conte’pastel pencils and a blending stump. Brightness was slightly decreased after scanning.
Telescope: 10 inch f/ 5.7 Dobsonian and 6mm eyepiece 241x
Date: 11-2-2007 11:40-12:40 UT
Temperature: 0°C (32°F)
Clear, calm
Seeing: Antoniadi III
Co longitude: 115.4°
Lunation: 22.3 days
Illumination: 43.6 %

Frank McCabe

Note to visitors: Frank dedicated this stunning sketch to Rich Handy last week in the Cloudy Nights sketching forum. Thank you Frank. I’m sure we all echo your wish that Rich have a speedy rebuild and return home.

Jeremy

A Fiddle on the Lake of Time

On October 30, site administrator, Rich Handy, lost his home to a fire. He and his family are ok, but as you can imagine he has a lot to deal with right now. Please keep him in your thoughts during this very difficult time. Until Rich feels ready to return to administering the site, I’ll do my best to keep things going. I’ve updated the submission page to include an email address to which I have access.

Rich has been very conscientious about not posting any of his own sketches here. I think this is an appropriate opportunity to dedicate the November 1, 2007 Astronomy Sketch of the Day to one of his many excellent Lunar sketches.

Hang in there Rich, we’re all pulling for you,

Jeremy Perez

Here are Rich’s notes about the beautiful surroundings of Hainzel, Hainzel A and Hainzel C:

In the south western quadrant of the Moon, amidst the heavily bombarded highland terra and adjacent to Lacus Timoris (the poetically named “Lake of Time”), lies the trio of complex overlapping craters, Hainzel, Hainzel A and C. A quick look at this grouping in this lighting may leave one with the mistaken impression that these three are the result of a single asteriod that broke into a couple of major chunks just prior to impact, resulting in the elongate structure without an obvious wall separating the two larger impacts. Despite that appearance, however, each crater was formed at a different epoch.

78 km Hainzel which comprises a good portion of the southern portion of the “fiddle” shaped complex, is a Nectarian era feature, formed sometime between 3,920 and 3,850 million years ago. In my sketch you can see that indeed, the lower crater has taken several impacts to it’s rim. In contrast, 38 km Haizel A above it, is a relatively youthful Erastosthenian era crater formed between 3,200 and 1,100 million years ago. Here again its youth can be gaged by the very fresh looking glacis, shown in my sketch as the ropey and branching area to the upper right of Hainzel A’s rim (the upper body of the fiddle). The drawing shows few superposed craters over this large area, a definite indicator of freshness. 19 km by 28 km Hainzel C is an Imbrium era crater formed during the gap in time between Hainzel and Hainzel A’s appearance between about 3,800 million and 3,200 million years ago. The light was not favorable for a good look at C, covered as much as it it was by deep shadow from it’s bigger brothers. Hainzel C is superposed on Hainzel. Previous views of C showed a damaged and disrupted floor and walls, most probably the result of the impact of A.

Here are the sketch details:

Subject: Hainzel, Hainzel A and C Rukl: 63
Date: 10-2-06 Time: 4:24 UT-5:43 UT
Seeing: Antoniadi III-IV Weather clear, light breeze
Lunation: 10.65 days Phase: 55.7 deg Colongitude: 39.5 deg
Illumination: 78.2%
Lib in Lat: +4 deg 55 min Lib. in Long: -5 deg 11 min
Telescope: 12″ Meade SCT, f/10
Binoviewers: W.O. Bino-P with 1.6X Nose piece
Eyepieces: 12.4 mm Meade series 4000 Super Plossls
Magnification: 393X
Sketch medium: White and black Conte’ Crayon on black
textured Strathmore paper.
Sketch size: 18″ x 24″

Floor Fractured Crater: Furnerius

Just two days past full moon, floor fractured crater Furnerius (125 km.) was well
placed relative to the sunset terminator to show off its interesting features.
This crater is one of the four large walled plain craters along the 60° E.
longitude line. Furnerius is the southern most of the four and placed not far from
the southeastern lunar limb. The other three which were visible at the eyepiece
from south to north but not sketched here are Petavius, Vendelinus and Langrenus.
Crater Furnerius is a pre-Nectarian crater and thus very ancient. It predates the
formation of the Nectaris basin. Basin debris and secondary impacts are scattered
across the floor and rim of this old battered crater. On the north side of the
crater floor a rille of 50 kilometers called Rima Furnerius can be seen. It
crosses the floor to the southeast and climbs the inner crater rim. Darker
smoother lava flooded areas can be seen on parts of the crater floor between the
rubble strewn regions created
by the basin impact. Inner wall terraces and central peaks are completely absent
from this crater but large crater Furnerius B(22 km.) is clearly visible on the
floor. On the glacis of this crater to the north a bright young 12 km. crater
called Fernerius A can be viewed in line with Rima Furnerius. To the northwest a 75
km. Copernican era crater Stevinus, stands impressively with its sharp rim, central
mountain peak and low hills. South of Furnerius a smaller yet equally ancient
crater Fraunhofer (57 km.) was showing a dark flat half shadowed floor. On the
northwestern rim of this crater Fraunhofer V (24 km.) could be identified by a
small sliver of light striking its inner southeast rim.

Sketching:

For this sketch I used: black Strathmore 400 Artagain paper, 9”x12”, white and
black Conte’pastel pencils and a blending stump. Brightness was slightly decreased
after scanning.

Telescope: 10 inch f/ 5.7 Dobsonian and 6mm eyepiece 241x
Date: 10-28-2007 6:05-7:45 UT
Temperature: 0.7°C (33°F)
Clear, calm
Seeing: Antoniadi III- IV mostly poor
Co longitude: 115.4°
Lunation: 17 days
Illumination: 93.7 %

Frank McCabe

The Compelling Late Old Moon

South is up and west is to the left in this sketch I made this morning near
daybreak of day 27 for lunation 1048. I knew the view would be poor because I
could not wait at all for the scope’s primary mirror to cool down. Therefore I
kept the magnification low and decided to sketch the compelling region from the
Ocean Procellarum to Sinus Roris. At the top of the sketch closest to the lunar
equator and near the terminator, you can see crater Reiner a 53 km. crater and to
the west of this crater is the famous bright feature Reiner Gamma. Crater Olbers
responsible for the rays in the region is lost in the bright area near the limb.
Most of the craters in this late lunation have floors in darkness and look quite
spectacular through the eyepiece. The longest bright ray from south to north
passes east of the crater pair Cardanus and Krafft both about 50 km. in diameter.
On northward a couple of hundred kilometers and just west of the bright ray the
dark crater Seleucus can be seen and further along to the east of the ray lies Schiaparelli. Most of the remaining craters visible lie on the limb side of the continuing ray and include: large crater Russell (105 km.) with smaller Briggs and Briggs A just to the east.
Continuing on northward across the dark smooth ocean, craters Lichtenberg and
larger Lavoisier A can be seen. At this point the bright limb highlands feature
Harding and Dechen showing bright ejecta blankets near the edge of Sinus Roris. On
the terminator side dome complex Mons Rumker is about to experience sunset.
Finally at the far northern end of the sketch is Markov a 40 km crater on the
floor of Sinus Roris. Seeing the moon early in the morning late in a lunation is
always a pleasant and memorable sight.

Sketching:
For this sketch I used: black Strathmore 400 Artagain paper 12”x 7”, white and
black Conte’ pastel pencils a blending stump and my index finger too. Brightness
was slightly adjusted after scanning.
Telescope: 10” inch f/ 5.7 Dobsonian and 21mm eyepiece 69x

Date: 10-8-2007 10:30-11:15 UT
Temperature: 22° C (72° F)
Clear, calm
Seeing: Antoniadi III
Colongitude: 234.1 °
Lunation: 27 days
Illumination: 7 %

Frank McCabe

A tilted cup

Walled Plain Crater Fracastorius

Lunation day five has walled plain crater Fracastorius (124 km.) basking in the
morning sunlight on the south edge of Mare Nectaris as it has each lunar orbit
for more than three and three quarter billion years. The shallow plate shaped
basin that Fracastorius rests upon subsided from accumulated lava mass and this
over time tilted the crater toward the center of the basin. Eventually the lava
building up in the basin was able to find a breach in the low tilted north wall of
the crater and continued to flow in hiding the central peak and most of the north
wall beyond the breach. Some of the floor of Fracastorius is covered by lavas that
are lighter in color than the dark lava covering most of the Sea of Nectar.
Northward out into Mare Nectaris is the much younger, small (12 km.) bright rimmed
crater Rosse standing alone in this part of the lava sea.

Sketching:
For this sketch I used: black Strathmore 400 Artagain paper, white and black Conte’
pastel pencils and a blending stump. Contrast was slightly adjusted after scanning.
Telescope: 10 inch f/ 5.7 Dobsonian and 6 mm eyepiece 241X
Date: 5-22-2007 1:09-2:15 UT
Temperature: 22° C ( 72° F)
High thin clouds, calm
Seeing: Antoniadi III
Colongitude 331.8 °
Lunation 5.24 days
Illumination 32 %

Frank McCabe

Janssen and Fabricius in the Lunar Southeast

Janssen at 195 kilometers in diameter is a large ancient (4 billion year old)
walled plain crater in the southeastern highlands and is not far from the lunar
limb. Relentless moonquakes and solar system debris impacts have given this crater
its old look. The floor of Janssen is covered by numerous smaller craters. Without
trying too hard I could see 20 crater including those down to a few kilometers in
diameter. The center of the crater appears to bulge higher than the worn rim. Much
of this could be debris from the large much younger impact crater Fabricius (79
km.). Fabricius is an Eratosthenian period impact crater. It clearly shows steep
sloping walls and exhibits a central mountain range that is about 11 km. long and
also a long central ridge that is more than twice that length. Geologists tell us
that much of the debris across the floor of Janssen is Nectaris impact ejecta;
fluidized where the floor is smooth and irregular boulder-like where the floor
appears tortured. But perhaps the most interesting feature here is 140 kilometer long Rimae
Janssen. This rille looking like a graben, where it cuts through the high central
region south of Fabricius. It then narrows suddenly before reaching the rim in the
relatively smooth region of the floor. Pits that are visible via high resolution
images in these narrow regions imply volcanism. There is at least one dome on the
floor of Janssen but I was not successful in spotting it in the current
illumination. Craters Janssen and Fabricius presented fascinating features to
examine during this observation.

Sketching:
For this sketch I used: black Strathmore 400 Artagain paper, 7”x11”, white and
black Conte’ pastel pencils and a blending stump. Brightness was slightly decreased after
scanning.

Telescope: 10 inch f/ 5.7 Dobsonian and 6mm eyepiece 241x
Date: 9-29-2007 6:15-7:15 UT
Temperature: 16°C (60°F)
Clear, calm
Seeing: Antoniadi III
Co longitude: 122.1°
Lunation: 17.73 days
Illumination: 91.4 %

Frank McCabe

Like a Tart

“She appears like a tart that my cooke made me last weeke, here a vaine of bright
stuffe, and there of darke, and so confusedlie all over. I must confess I can see
none of this without my cylinder”.

These were the honest words of William Lower an amateur astronomer written upon
observing the Moon with his new “perspective cylinder” in 1608.
In the history of Man Kind this is but a heart beat in time but how the telescope
has evolved from that primitive Galilean spy glass that only the privileged few
could ever hope to own! Now even the most modest instrument delivers views of the
heavens and Moon in particular that our astronomical forefathers could only have
dreamt of!

One thing that hasn’t changed for me and countless others is the “confusedlie” of
the Moon. It is an awe-inspiring yet bewildering sight to all but the most
experienced lunar observer. I myself am very much a Lunar apprentice and each time
I fly over the terminator with my telescope and settle upon “she who takes my
heart” I am learning my way around not only the shadows, bright ridges and crater
rims but through my post sketch research feature names, dimensions and geological
composition.

On the late evening my visual voyage of 250,000 miles at the eyepieces of my
binoviewer was just such an adventure.
I deliberately selected a relatively demure region, shunning the bright and large
craters in a deliberate attempt to stray from the well trodden path.

It turns out that my target area turned out to be Lacus Exellentiae. I was
initially drawn to a crater with a brightly lit rim just to the left of centre in
my drawing that my subsequent atlas searches found as being nameless apart from
being marked as (b) in a few of the atlases I own . The crater on the right close
to the terminator however turned out to be Clausius with a diameter of 24km and
was situated close the controlled crash site of the European Smart -1 Lunar
orbiter on September 3rd 2006.

A happy hour spent and no longer so Confusedlie!


    Moon 11 days
   14″ (350mm) Newtonian 193x
    Sketch with Derwent watercolour pencils, Derwent Pastel pencils & conte hard
    pastels. Blending stumps used, sketch on lightweight black card.
    Finished worked scanned but un processed.

    Dale Holt
    Chippingdale observatory, Nr Buntingford, Hertfordshire UK