Dark halo craterlets

Dark halo craters and craterlets (DHC)

Description

Dark-halo craterlets (DHC) and low albedo spots abound on the moon! The most ideal way to discover them, or to make a catalog of them, is to observe the Full Moon through a common or powerful telescope, and to take a close look at the equatorial (shadowless) photographs made by the Clementine probe, which orbited the moon in 1994.
 
 The Clementine Atlas of the Moon by Ben Bussey and Paul Spudis (2004) is the best possible source to explore printed versions of the Clementine photographs. The best on-line source of those photographs is the USGS Map-A-Planet site.
 
 

An experimental LAC-related list of dark halo craters and craterlets

(note: all of the mentioned dark regions and other dark spots are about to be moved to the lists in the page LUNAR LACUS)

• LAC 23: dark spot at 37°15' North/ 46°20' West, as part of Rima Mairan.
• LAC 41: three of Apollo 15's orbital close-up Hasselblad photographs of the area near Dorsum Gast (the western part of Mare Serenitatis) show a remarkable bright craterlet with unexpected dark "tongue" of ejected material at the southwestern rim of it, located at the southern end of Dorsum Gast. The exact coordinates of the craterlet are: 23° North/ 8°40' East. The three Hasselblad close-ups of the craterlet are:
  • AS15-81-10876
  • AS15-81-10881
  • AS15-81-10883
  • Apollo 17's Hasselblad of that craterlet: AS17-149-22881.
• LAC 44: dark-halo craterlet in Cleomedes (see Bruno Daversin's LPOD of October the 6th, 2004).
• LAC 46: dark-halo craterlet south-southwest of Malyy, dark-halo craterlet northeast of Malyy G.
• LAC 47: dark-halo craterlet in Deutsch.
• LAC 54: Mees Y; the dark lacus-like region immediately north of Mees itself (see also LAC 72).
• LAC 55: dark-halo crater near Sundman (9° North/ 90° West). See also LPOD April 26th, 2009
• LAC 58: dark-halo craterlet Copernicus H, and many small dark-halo craterlets east of Copernicus and at Mare Insularum (see LPOD How thick are rays?).
  • Frame 148, made by Lunar Orbiter 5, shows the dark-halo craterlet Copernicus H.
• LAC 59: dark-halo craterlet west of Manilius, and many small dark-halo craterlets near Sinus Aestuum (see LPOD How thick are rays?).
  • AS15-93-12683 is an orbital Hasselblad of the dark-halo craterlet slightly west of Manilius.
  • AS15-P-10169 also shows this dark-halo craterlet.
• LAC 60: the remarkable halo of dark rays around Dionysius, which is also mentioned on chart 12 of the 21st Century Atlas of the Moon (C.A. Wood/ M. Collins).
• LAC 62/ LAC 63: dark-halo craterlets on the floor of Condorcet P, see the central part of Apollo 16's panoramic ITEK-camera frame AS16-P-2626.
• LAC 64: dark-halo craterlet in Mare Marginis (11°30' North/ 93°30' East), and another dark-halo craterlet east-southeast of Jansky F.
• LAC 67: dark floor of Kohlschütter.
• LAC 69: dark streak (or flow) on the floor of Korolev X.
• LAC 72: dark-halo crater near Sundman (see also LAC 55). Mees Y; the dark lacus-like region immediately north of Mees itself (see also LAC 54).
• LAC 73: small dark spot northeast of Schluter, at 2°55' South/ 81°20' West.
• LAC 76: very dark craterlet southwest of the bright Lassell D (photographed during the mission of Apollo 16), and the dark Mons Moro in Mare Cognitum (this could be one of the most low-albedo formations on the entire moon's surface!).
• LAC 77: the three dark spots on Alphonsus' floor. One of them was called "Lake Titicaca" by E.A.Whitaker.
• LAC 83: dark lacus-like region on the floor of Langemak.
• LAC 85: dark region north, northeast, and east of Dewar.
• LAC 90: dark halo crater in an unnamed "lake" of Montes Rook, at 10° South/ 96°30' West. On page 180 (LAC 90) of the Clementine Atlas, this dark halo crater is not noticeable because of the pure black appearance of the "lake" in which it is located. The LRO's online ACT-REACT Quick Map shows the dark halo crater very well!
• LAC 92: Crüger and Zupus.
• LAC 94: dark spot at 19°30' South/ 10°55' West, near the ridge Nicollet Psi (note the "black dot" near the upper left corner of LPOD Succession). See also the Hi-Res scan of Lunar Orbiter 4's photograph LOIV-113-h2.
• LAC 98: dark-halo craterlet southeast of Holden.
• LAC 99: dark spot southeast of Legendre, east-northeast of Adams (30°30' South/ 72° East). See LPOD The Adams Family.
• LAC 100: dark spot on the southern part of Curie's floor, west-southwest of Curie K.
• LAC 101: dark-halo craterlet on the northwestern part of Neujmin's floor.
• LAC 101: two dark mare-like spots on the floor of Waterman.
• LAC 102: partially dark floor in Isaev.
• LAC 104/105: dark floor of Rumford.
• LAC 108: many dark-halo craterlets in Mare Orientale.
• LAC 108: dark spot at 108° West/ 29° South (west of Mare Pacificus).
• LAC 109: dark-halo craterlet Inghirami W north-northeast of Inghirami.
• LAC 110: Harold Hill's "Basaltic Lava Areas" near Vieta.
• LAC 112: Walther A: dark spot, depicted in the exceptionally wonderful LPOD Whitewashed! Note: dark spot Walther A is seen near the upper margin of Clementine's photo-version of LAC 112, page 224 in the Clementine Atlas.
• LAC 113: Buch B, Maurolycus A, and Maurolycus F: dark spots, depicted in the exceptionally wonderful LPOD Whitewashed!
• LAC 116: many dark-halo craterlets in Mare Australe, between Gernsback and Lamb.
• LAC 117: dark mare-like region on the floor of Bolyai.
• LAC 123: dark spot at 98° West/ 35° South (south of Mare Pacificus).
• LAC 140: dark-halo craterlet in Schrödinger.

Additional Information

• List of pyroclastic deposits.
• ALPO 1976 list of dark-haloed craters in Selected Areas Program Handbook. Lunar Selected Areas Program Handbook (2002).
• Kurt Fisher's dark halo crater lists.

LPOD Articles

Leaks (the dark-halo crater at 9° North/ 90° West, near Sundman).
How thick are rays? (the many dark halo craterlets east of Copernicus).
More Highland Plutons (dark spots at Maurolycus and Buch B).
Whitewashed! (dark spots Maurolycus A, Maurolycus F, and Buch B).

Bibliography

• ALPO. 2002. Lunar Selected Areas Program Handbook.
• Bussey, Ben and Paul Spudis. 2004. The Clementine Atlas of the Moon (Cambridge University Press).
• Garfinkle, R. A. 1998. A.L.P.O. lunar dark-haloed crater catalog: updated, corrected, and amended. Strolling Astron., Vol. 40, No. 4, p. 181 - 184
• Antonenko, I. (2013) Re-examining the identification of dark halo craters: New criteria for modern data sets. 44th Lunar & Planetary Science Conference #2607.

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