Piccolomini is a prominent lunar impact crater located in the southeastern part of the Moon, to the southwest of the larger and more ancient crater Janssen. It is named after Enea Silvio Piccolomini (1405–1464), who later became Pope Pius II. Its well-preserved features make it a notable landmark for lunar observation.
Characteristics
Piccolomini is approximately 88 kilometers (55 miles) in diameter. Its rim rises significantly above the crater floor, with a depth of about 4,500 meters (14,800 feet) from the rim to the floor.- Walls: The inner walls are heavily terraced, showing distinct slump features resulting from the initial impact and subsequent gravitational collapse. These terraces are particularly prominent, giving the crater a rugged and complex internal structure.
- Floor: The interior floor is relatively flat in the central region but becomes more rugged and irregular towards the base of the terraced walls.
- Central Peak: A complex and massive central peak formation is present, rising to an elevation of about 2 kilometers (1.2 miles) above the crater floor. This peak is multi-ridged and fractured, a common feature in large, well-preserved impact craters.
- Age: While its remarkably well-preserved features suggest a relatively young age for a large lunar crater, Piccolomini is generally believed to be of the Nectarian period, implying formation around 3.9 billion years ago. Its pristine appearance might indicate a later modification or a formation within the younger end of that period or early Imbrian.
Location and Observation
Piccolomini's location makes it a distinctive feature when observing the Moon, particularly when the terminator (the line dividing lunar day and night) passes over it. At this time, the low-angle sunlight highlights its deep shadows and prominent central peak, making its features highly visible through amateur telescopes. It serves as a good reference point for other nearby features in the Moon's southeastern quadrant.Satellite Craters
By convention, these features are identified on lunar maps by placing the letter on the side of the crater midpoint that is closest to Piccolomini.| Name | Latitude | Longitude | Diameter (km) |
|---|---|---|---|
| Piccolomini A | 27.5° S | 30.4° E | 16 |
| Piccolomini B | 27.2° S | 29.0° E | 13 |
| Piccolomini C | 28.6° S | 31.1° E | 26 |
| Piccolomini D | 26.3° S | 32.3° E | 17 |
| Piccolomini E | 26.0° S | 33.7° E | 18 |
| Piccolomini F | 26.2° S | 31.8° E | 11 |
| Piccolomini G | 27.2° S | 31.8° E | 18 |
| Piccolomini H | 27.9° S | 28.5° E | 11 |
| Piccolomini J | 25.0° S | 30.1° E | 28 |
| Piccolomini K | 25.7° S | 29.8° E | 8 |
| Piccolomini L | 26.7° S | 30.6° E | 12 |
| Piccolomini M | 27.8° S | 31.8° E | 23 |
| Piccolomini N | 29.2° S | 26.2° E | 23 |
| Piccolomini O | 29.1° S | 27.4° E | 17 |
| Piccolomini P | 30.4° S | 29.5° E | 17 |
| Piccolomini Q | 30.8° S | 28.7° E | 14 |
| Piccolomini R | 29.3° S | 30.4° E | 16 |
| Piccolomini S | 31.7° S | 31.5° E | 21 |
| Piccolomini T | 28.4° S | 27.0° E | 6 |
| Piccolomini V | 29.0° S | 28.9° E | 14 |
| Piccolomini W | 29.8° S | 27.2° E | 13 |
| Piccolomini X | 30.0° S | 26.6° E | 23 |
| Piccolomini Y | 31.0° S | 30.7° E | 14 |
| Piccolomini Z | 31.2° S | 33.5° E | 24 |