Astronomy Picture of the Day: 15/01/2026

Object Name: Apennine Mts and surrounding area

Copyright: Julie Straayer

Location: Albany Creek, Queensland

Connect: NA

Skill level: Advanced (5+ Years)

Image Title

Apennine Mts Region at First Quarter

Artists' statement

It was the first time in a long time that I had my Skywatcher 150 mak out using my new Fusion mount and trying out my new Motorola Edge 60 Fusion phone. The seeing was particularly good on the night, enabling me to capture the individual peaks found within the Apennine range. I particularly love capturing the Moon whilst trying to keep the image as natural as I can (as I see it through the telescope).

How This Image Was Captured

Gear used

Skywatcher 150 Maksutov

Skywatcher Fusion mount

Motorola Edge 60

Fusion Starguider 12mm eyepiece

Exposure details

ISO 935 Exp 1/50 sec@ F1.8

Processing notes

Single image edited with the Aviary App

Exploring The Apennine Mountains Region

The Apennine Mountains (Montes Apenninus) are among the most striking mountain ranges on the Moon, and they are especially impressive when observed at First Quarter. At this phase, the lunar terminator passes directly across the range, placing the mountains at lunar sunrise. The low angle of sunlight produces strong contrast, causing long shadows that dramatically emphasise the height and rugged structure of the terrain.

Stretching for approximately 600 kilometres, the mountains form the south-eastern boundary of Mare Imbrium. The range was created by the immense impact that formed the Imbrium Basin, which thrust vast sections of the lunar crust upwards. Some of the peaks rise to heights of five to six kilometres, making them comparable to, and in some cases taller than, major mountain ranges on Earth.

Through binoculars, the mountain chain appears as a jagged arc bordering the mare, with individual peaks becoming discernible as the eye adjusts to the contrast. A telescope reveals even finer detail, including prominent peaks such as Mons Huygens, the tallest in the range, along with sharply defined ridges and shadowed valleys that highlight the scale of the landscape.

The First Quarter Moon is widely regarded as the optimal time to observe the Apennine Mountains because the lighting maximises topographic relief. As the Moon continues towards Full, the Sun rises higher over the range, shadows shorten, and much of the dramatic relief is lost. While the mountains remain visible, they appear flatter and less defined, making the First Quarter phase the most rewarding for both visual observers and lunar imagers.

Behind the Selection

The image was chosen for its depiction of the Apennine Mountains at First Quarter, when the lighting most clearly reveals their dramatic form. At this phase, sharp, isolated peaks are illuminated by low-angle sunlight while their lower slopes remain in darkness, producing a striking contrast between bright summits and deep, black shadows. This interplay of light and shadow gives the mountains a strong three-dimensional appearance and clearly defines the boundary between the smooth lava plains of Mare Imbrium and the rugged, heavily cratered highlands beyond.