Today I had a nice opportunity to spot the “Lunar X” on the First Quarter Moon! The Lunar “X” is a well-known “optical feature” on the Moon, which resembles the letter “X” when the lunar terminator is along just the right lunar longitude. The intersecting crater walls of Purbach, La Caille and Blanchinus make the illusion “X” that is only visible for a short time.
Based on my observations during the past few months, it is possible to see the Lunar X when the moon is nearly 54% illuminated.This is why you cannot see it every month. In fact, the last time I was able to image it was during October 2012.
By the way, I refer to Stellarium, a free planetarium software, to determine the lunar phase and illumination during a particular date and time for my location. Note that the values given by Stellarium may not be very exact, but they are still very useful as guides for amateur astronomers.
My first image of the Lunar X:
Both images were taken using my Canon Powershot SX40 HS camera.
Click on image to view larger version
Before the world ends (just kidding! LOL), here’s my lunar cycle montage 🙂 Wheew. A month’s worth of work.
It’s been said that night photography has long been the realm of the persistent, strong willed…and sleep deprived few. LOL. However, despite being challenging, it is also a very interesting and rewarding venture. With the relatively decent weather last month until early December, I decided to try and capture the moon for as many nights as I could and then create a montage showing the different phases. Trying to catch a full sequence under Philippine skies isn’t the easiest thing to do! Favorable sky conditions may only arise a few times a year so I took this opportunity.
Please take note that no image was taken during December 4, 2012 because of the thick cloud cover during that day. What I did was I used a similar image (having almost the same phase and % illumination) that I took last October 31, 2012 as a replacement to fill the whole cycle.
All individual images were taken using my trusty Canon Powershot SX40 HS superzoom camera. Had to wake up during the wee hours of the night and endure a few mosquito bites only to image each one, especially the waning crescent phases. Haha. But I’m glad I did. Time and patience has paid off. 🙂