The area on either side of the crater Metius (90km diameter) seen near center in this image, is complex and fascinating. To the right is the obvious Vallis Rheita, formed when ejecta from the Mare Nectaris impact created a line of over a dozen craters. The crater Rheita (71km) itself can be seen at the top of this line in the image with it’s little central peak. Some lunar researchers see Vallis Rheita as two separate but overlapping troughs as evidenced by the bend in the middle with the farther portion coming from the impact of Nectaris that it points back to, while the western portion (nearer the terminator) points south of the Mare on a line with Fracastorius and Theophilus. Before we move on, notice the odd crater to the right of Rheita, Rheita E, obviously formed from 4 or 5 craters being merged. To the immediate left of Metius is a slightly smaller crater Fabricius (80km) known for … Continue reading →
About Richard Hill
Richard “Rik” Hill
Born: June 10, 1949 only a few hours after Antares was occulted by a nearly full moon.
My first observation was the May 6th, 1957 transit of Mercury as a schoolboy in a two room schoolhouse in rural Oakland County, Michigan, when a substitute teacher brought a 1.6” Unitron to school and projected an image the sun. She had the wrong day but the sunspots on the Sun fired me up on astronomy at the age of 8! So to that extend, I was a pre-Sputnik amateur astronomer…by 5 months.
I observed through the 1960s, first with the standard 2.4" refractor (Tasco) and later with an RV-6 I bought with money earned mowing lawns and washing cars. I occasionally attended evening astronomy classes at Cranbrook Institute of Science though I did not have good grades in school because I spent all my study time with Sky & Telescope or girls. These poor grades led to my being drafted very quickly after graduation but instead I joined the Navy. In the Navy I served as a radar tech. but was frequently called up by the navigators to help identify stars for sextant fixes. (A very early form of GPS!) A high point in my time in the Navy was when my ship was chosen as the Atlantic backup recovery ship for Apollo 8. We were, of course never used but we got to practice a lot with a dummy capsule and had one of the later Apollo astronauts on board.
After the Navy, I sold the RV-6 to a high school girl who was the only one in the whole Detroit area (then 2 million people) that answered the ad. I was surprised to find she lived in my neighborhood and went to school with my sisters. The young girl and her friend called on me to help them start and astronomy club at their school, the same high school I attended. A year and a half later, in 1974, I married that girl, Dolores, and we're still married. I am committed to a lifetime maintenance contract on the old RV-6!
I joined the Association of Lunar & Planetary Observers (ALPO) and the American Association of Variable Star Observers (AAVSO) in 1975 and have been active, to some degree, in both organizations since. That same year my Dolores and I founded (along with another person) The Sunset Astronomical Society in Midland, Michigan. It is still going strong today.
In 1979, I was hired by Warner & Swasey Obs. (Case Western Reserve Univ.) to operate their Burrell Schmidt telescope being moved from Cleveland, Ohio to Kitt Peak. I worked there for 12 years until the grant was terminated. In 1982 Walter Haas (Director and founder of the ALPO) asked me to found the Solar Section, which I did. (early history at: http://www.alpo-astronomy.org/solarblog/?page_id=209) I left that position in 2004 after one full magnetic solar cycle as Recorder/Coordinator. Hearing of my retirement the ALPO reinstalled me as Coordinator of the Solar Section in 2016. The sun’s instant reaction was to hide all the big sunspots!
In 1992, when Warner & Swasey’s Nat’l Science Foundation grant failed to get renewed I began work with the Planetary Atmospheres and Planetary Occultations groups at the Lunar & Planetary Lab of Univ. of AZ. In these groups I worked with every planet in the solar system and many of the moons. That job lost its funding in Dec. 1999 (common problem in this business) and 20 minutes after being informed of this I was picked up by Steve Larson for work with the Catalina Sky Survey (CSS), an Near Earth Asteroid search project, from which I retired in Oct. 2015. With CSS I have been enjoyed some of my greatest observing challenges but the rewards were high. I discovered thousands of asteroids some that have passed closer than the moon, 27 comets and named a over 120 asteroids.
Now I am working on astronomy at my home observatory, fossils I've collected over 35 years, my bonsai trees, vegetable gardens and the taking in rescue cats.
As each lunation begins one of the first craters that stands out is Petavius (182km dia.) with the large wide rima that crosses the crater floor from the central peaks to the southwestern wall. In my first lunar image of the crescent moon in 1972 (taken on Tri-X film through my RV-6 telescope) my eye was immediately drawn to this remarkable crater. My curiosity and interest in this feature grew over the years until I had the opportunity to view it through the 61″ Kuiper Telescope (formerly known as the Catalina Reflector) at f/13.5 or 823.5″ focal length (just under 210 cm). The view was breathtaking. The formerly straight rima was ragged edged cutting through the central peaks and accompanied by a number of other rimae on the floor. So don’t be afraid to crank up the magnification on this feature if the seeing will allow! To the left of Petavius are two similar sized craters, Snellius (85km) and further … Continue reading →
The moon is just a thin crescent in the bright twilight sky as this trio of craters creep out from the lunar night. The large one on the right is Endymion (129km dia.) an ancient walled plain that was formed about 4 billion years ago (b.y.) . It’s accompanied by the younger Atlas (90km) below center with it’s contained system of Rimae Atlas a mere 3.2-3.8 b.y. old. It has a impressive ejecta blanket to the east and south where the material was piled up outside the crater wall. Atlas is followed by the shadow filled Hercules (71km) to the west, the youngest of the trio at 1.1-3.2 b.y. old. Above Atlas is a very young crater Keldysh (34km) and between them the totally ruined crater Atlas E. It’s obviously older than Atlas since the ejecta from the Atlas impact is splattered across the whole width of Atlas E. To the east (right) of Atlas is a large flat area. … Continue reading →
I always look forward to the appearance of the 104km diameter crater Plato and surrounding environs as they emerge from the lunar night. There is so much to see there I find imaging irresistible. Usually I don’t like to do this wide a field but there’s much to enjoy. Plato’s terraced walls exhibit ancient slumping and breaches by rimae. South of Plato are the sparkling Montes Teneriffe with 2400m high Mons Pico the large peak on the east (right) end. To the east of Plato is the great gash Valles Alpes with it’s central rille seen here (with a 6″ telescope) with another isolated mountain peak south of the entrance to the Vallis, Mons Piton (2250m) standing isolated on the plain of Mare Imbrium. In the lower right corner of this image is Cassini (60km) with it’s tight ejecta blanket surrounding and interior wrinkles and satellite craters. Above Plato is a large flat region that is Mare Frigoris, the longest … Continue reading →
North of Theophilus, in the lower left corner of this image, is Sinus Asperitatis running diagonally across this image, with the pear-shaped crater Torricelli in the middle. The crater is listed as 24km diameter which refers to the larger portion with extension adding a few more kilometers to the west. This odd shape is due to the merge of two impacts though the wall between the two is very low step. It sits on the northern edge of an unnamed ancient flooded crater some 90km across whose walls can be made out in this low angle sunset lighting. Near the bottom middle of this image is the shadow filled crater Isidorus (43km) that appears pear-shaped as well. Note how the mountains around Isidorus are soft looking, overlain by ejecta from the tremendous Theophilus impact. Compare them to the peaks north of Torricelli. You will see at the top edge of the image the crater Maskalyne (26km) and left *(west) of … Continue reading →
When the Moon is not quite 10 days old you can get a good look at a few of the more obvious domes in the Mare Nubium area south of Bullialdus. The first key is to locate Kies, the 46km diameter crater at the top of this image with the little tail pointing down. Notice the mild swelling just to the left of the crater. This is Dome Kies Pi or K1. It’s 10km in diameter with a little 2km craterlet at the summit, just barely visible here. Going further to the left there are two small clusters of mountains. Just above the farther one is another mild swelling, K3. A third dome is just off the end of the tail of Kies but I never have gotten a good image of it. It may be just to low a feature. Below Kies you see a graben-like rima, Rima Hesiodus that runs some 309 km from Hesiodus just south of … Continue reading →
Seven days into this particular lunation, we had a favorable libration just at the northern edge of the limb on this image. It allowed for a very good view of a couple craters not usually seen so well. The large dark area in the lower left is the north shore of Mare Crisium and Mare Angius the dark meandering patch on the right side of Crisium. Notice just above it is the large crater Cleomedes (129km dia.) and above that is the well defined Geminus (88km). Then at the top edge of the image is Messala (128km) with its nicely terraced walls. Moving towards the limb you see another fairly well defined crater, Berosus (77km) and to the lower right another similar sized crater with a curious dark stripe across it’s floor, Hahn (87km). It appears from Lunar Orbiter images and the Gazetteer of Planetary Nomenclature: 1:1 Million-Scale Maps of the Moon, that most of the northeast half of the … Continue reading →
South and east of Posidonius is the crater Romer (41km dia.) seen here at the top of this image with starkly terraced walls and an off center peak on its floor. It’s a young crater and its shape is strongly affected by the topography it was created in. Twin 12km craters below it are Brewster on the left and a little lower on the right is Franck. These both sit in the western reaches of Sinus Amoris with Mons Miraldi, a round mound on the southern shore of the Sinus just north of the low walled crater Miraldi (41km). Moving further south is the crater Gardner (19km) and to its west (left) is the flat floored Vitruvius (31km) half in shadow. South and west of Vitruvius is a smaller crater, Dawes (19km) with an interesting set of ridges on the east side of the crater, followed by Plinius (44km) with Rimae Plinius north and Promontorium Archerusiz next to it. Notice … Continue reading →
Early in every lunation you can see this region on the moon and though I have covered it before, I discovered some remarkable new things on this particular visit. First a little orientation. Notice the Mickey Mouse configuration in the upper left. The left ear is the crater Licetus (77km diameter) and the right is Cuvier (also 77km). Between them is the unusual north-south elongated feature, Heraclitus with an odd central ridge. This is the result of a merger of two or three craters. The large flat floored crater near the center of this image is, Manzinus (100km). Then the large crater on the right edge of this image with the central peak is Vlacq (92km). This should serve to give the outlines. When processing this image, a montage of two images, I thought I saw an artifact of the knitting process about midway up the terminator. It’s a little dotted horizontal line and above the left end the barest … Continue reading →
A day or two short of the full moon, depending on the libration, on the northwest terminator of the moon you will find a remarkable crater that catches the eye. This is Pythagoras (133km dia.) with beautifully terraced walls and a central peak that casts great shadows across the western side of the crater and the west wall. The extreme near limb presentation of this magnificent crater gives us the opportunity to see just how shallow craters are. When on the terminator near the center of the moon, they look like deep wells but in this case the depth is only 4.8 km or 3.75% of the diameter! Shallow indeed! You can see this for yourself by making a 100mm diameter crater that is only 4mm deep. The large non-circular crater in front of Pythagoras is Babbage (148km) and to it’s left is Oenophiles (70km) and further on is the smaller Markov (43km). To the lower right of Pythagoras is … Continue reading →
Center bottom we have the spectacular crater Tycho (diameter 88km) the center of the largest ray system on the Moon that completely wraps around the globe. This is two days after the terminator passed over this crater and already the sun is high enough to show the rays without washing out some of the topographic details. For orientation purposes, the large dark crater at the top is Pitatus. Just below that are two similar sized craters Gauricus (82km) on the right and Wurzelbauer (90km) and off to the right is a much smaller well defined crater with a fairly dark patchy floor, Hell (34km). To the left of Pitatus and you’ll see one of the better double walled craters on the Moon, Hesiodus A (15km) looking like a little bulls-eye target with the small central peak. The parent crater Hesiodus (44km) is above it with a small 5km central crater. Going back to Tycho we can see one of the … Continue reading →
The whole rim of Mare Nectaris is populated with wonderful features. Here we have the south side with the big scarp Rupes Altai below and left of center stretching from the beautiful crater Piccolomini (90km dia) at bottom going all they way up past the large Catarina (104km) some 495km. You can just barely see another pressure ridge, concentric to Mare Nectaris, running from Catharina down south of the large “U” shaped crater above center, Fracastorius (128km). Unfortunately the nice east-west rima that bisects this crater is just beyond the resolution of this image. But there are many secondary craters on its floor and a splattering of them in the upper left covering Beaumont (54km) a little brother to Fracastorius. These secondaries are likely the ejecta from the Theophilus impact to the north which must have been a fantastic sight!Continue reading →