An interesting photo because there are two pairs of famous twin craters that can be seen in the same photo.

At the top right we have Ritter and Sabine, and down the left we have Theon Senior and Theon Junior.

Twin craters - In the sense used here, the word '' twin '' means that a pair of nearby craters are similar in size and appearance. It does not necessarily imply that they were formed at the same time. Some twins are very pronounced and do not require large telescopes. A typical example: Cardanus / Krafft in the western part of the Oceanus Procellarum. Most of the twin lunar craters are too small to observe by ordinary telescopes. There are also the triplet craters, like the well-organized trio on the floor of Endymion. We listed below a list of famous and unknown twins, pairs, doubles, and triplets (observed by binoculars and telescopes of small, medium and large diameters).

• Ariadaeus and A. Simultaneous formation;

• Beer and Feuillée a famous pair. An unnamed catena runs east-southeast of Beer.

• Draper and Draper C in Mare Imbrium near the Carpatus Mountains are observed by ordinary telescopes.

• Eratosthenes A and B (south of Wallace) are seen on larger telescopes.

• Gambart B and C views on medium-sized telescopes. Gambart C was called Moreux by F.C.Lamech.

• Lichtenberg AA, at 29 ° North / 63 ° 20 'West observed in common telescopes and larger openings.

• Messier and Messier A (formerly known as W.H. Pickering), is the most famous pair on the lunar surface. Not exactly twins, because one of them is elliptical.

• Secchi Ae B; Smithson (formerly Taruntius N) and Taruntius O, northeastern Mare Fecunditatis (Sinus Successus) are seen in medium and large aperture instruments.

• Taruntius K and P, on the Dorsum Cayeux observed by medium telescopes.

• Carmichael and Hill, near Sinus Amoris. An interesting pair for small and medium telescopes.

• Helicon and Le Verrier. A famous pair in Mare Imbrium, near Sinus Iridum. Observable by small telescopes and binoculars.

• Ritter and Sabine, on the southwest edge of Mare Tranquillitatis. An interesting pair for small and medium telescopes.

• Ritter B and C. These are two bowl-shaped craters north of Ritter (they were almost recorded in this photo where only Ritter C appears). Among them is a small crater which is a good object for testing the telescope optics.

And now, will we pay more attention to the twin craters on our next lunar observation? It depends on you.

Source: Lunar Observation Guide - Rosely Gregio

Adaptation: Avani Soares