May 17 2010 Mon
12:44 am PHT
Occul—what? An occultation is an astronomical event wherein a heavenly body passes in front of another and hides it from view. That’s what happened earlier tonight: an occultation of the Moon and Venus. Most people saw the very close conjunction (an astronomical term signifying that two objects appear near each other in the sky) and appreciated the beauty of a “star” on top of a crescent moon. You can actually see plenty of pictures and status messages about this relatively rare Moon-Venus event and there were observations that it reflected some Islamic flags or that it looked like a one-eyed smile. What most didn’t know (and missed) was that the “star” was actually Venus and that the occultation itself is much more interesting scientifically. (In addition, the Moon and Venus are the 1st and 2nd normally brightest objects in the night sky so this occultation is actually quite special.)
I didn’t know that there was an occultation actually and I was just lucky that I went out of my house to go to Alabang and saw that beautiful sight in the twilight sky (see the image on top taken with a cellphone camera). Because of the position of the Moon and Venus, I knew that this wasn’t just a conjunction and that an occultation would also occur. So I quickly went online along the way and checked the expected time of ingress (or disappearance): around 7:36 p.m. I also noticed quite a few people on the road looking at the Moon and taking pictures. I arrived in Alabang at around 7:25 and waited for the occultation. Funnily, there was also another guy near the parking area with a camera propped on a tripod taking pictures as well.
Despite the lack of a stable base for my cellphone, I took several pictures to document the occultation. Then at around 7:37 p.m. I saw bright Venus gradually grow dimmer and dimmer and then finally disappear from view in a matter of seconds. You can actually see in the last photo above a dim remnant of Venus before it was completely obscured.
Unfortunately, my viewing condition is very not ideal. I didn’t mind too much since I have never really observed a Moon-planet occultation before despite my general interest in Astronomy. The best way to observe the occultation is with the help of a telescope zoomed in on the planet. Shown below is how it might have looked like when you can zoom in. (These images are generated from Stellarium.)