The last quarter moon will be visible in the night sky between February 9th and 10th, offering a prime opportunity for stargazers to observe its surface features in sharp detail. Rising in the southeast shortly after midnight on February 10th, the half-lit moon will appear alongside bright stars like Spica and Arcturus.
Why This Matters
The third quarter phase occurs when the left side of the moon is illuminated, creating dramatic shadows across craters and mountain ranges. This visibility is especially valuable because the lunar surface details are most pronounced during this phase, allowing for clearer observation of geological structures. The moon’s craters and mountains stand out because of the low-angle sunlight hitting them at this time.
Observing the Lunar Surface
The terminator — the dividing line between light and shadow on the moon — is the best place to focus your telescope. At this edge, shadows stretch across the lunar landscape, highlighting crater rims and the central peaks of formations like Herchel, Ptolemaeus, Alphonsus, and Arzachel.
- A telescope with a 9-inch aperture will easily reveal the central peaks within Arzachel and Alphonsus.
- Apollo 12 and Apollo 14 landing sites can be located near Mare Cognitum. Apollo 14 touched down over 55 years ago on February 5, 1971.
Lunar Geology and History
The moon’s terrain tells a story of ancient impacts and volcanic activity. Montes Appenninus, a 370-mile-long mountain range, is believed to have formed from the same asteroid impact that created the Imbrium basin, which later filled with lava to become the “Sea of Showers.” This highlights how lunar landforms are remnants of catastrophic events and subsequent geological processes.
The last quarter moon provides an ideal moment for amateur astronomers to explore lunar geology from their backyards, without the need for advanced equipment.
For those interested in observing the moon, binoculars or telescopes with moderate magnification will reveal surface details. Clear skies and minimal light pollution will enhance visibility. This event is a reminder of the moon’s dynamic past and its continuing role as a celestial beacon for scientific exploration.
