Occultation of Venus
Published on Apr 21, 2009 at 3:20 pm.
7 Comments.
Filed under observing, skywatching.
On Wednesday morning, the Moon will appear to pass in front of the planet Venus for some observers on Earth. Whenever the Moon (or some other astronomical body) passes in front of another body, we call it an occultation. This lunar occultation of Venus will be technically visible for many North American observers, but for most of us it will occur after sunrise. That makes it a bit tougher to see with the naked eye, but it should be visible in binoculars or telescopes (weather permitting).
The lit portion of the waning crescent Moon will pass over Venus first. Here in the Dallas/Fort Worth area, that will happen about 7:22 in the morning. That’s about half an hour after sunrise. The Moon will be new in only a few days, so the waning crescent will be quite narrow and difficult to see if there is haze or pollution. It will look something like the image above when seen through binoculars. If you are using a telescope, you’ll even see a phase to Venus (it will appear to look like a miniature Moon, itself, except without craters). If you were to zoom in on Venus, it would look much like the image below just before the Moon passed in front of it.
Then, after a while, the Moon will have moved out from in front of Venus and the planet will appear to reappear on the far side of the Moon. It will look something like the image below when seen through binoculars. For those of us in the Dallas/Fort Worth area, this will happen about 7:57am.
Now, these images were created for where I live. If you live farther south or east, then the Moon will appear to be passing a bit to the North. Most of Mexico misses the whole thing. Also, if you live too far to the East, you also miss the event. Miami, New York, and Atlanta all miss the event. Toronto gets to have a rather interesting sight as the edge of the Moon skims right past Venus. According to the program that I am using to visualize this event, that makes the Moon cover only part of Venus. That makes this a grazing occultation for Toronto, one of the most interesting to watch. If any of my readers are in the area, make sure that you get to look at it through a telescope if you can. I think that it will be about 9:15am for you to have the best view.
The Moon occults planets every now and then. I remember the first time that I saw it happen, though, I was a TA for an astronomy class. We had a special extra-credit observation at the observatory that morning before dawn. We observed several things that we couldn’t see in the evening skies. Then, just at early twilight, the Moon rose with Venus already behind it. About half an hour later, Venus popped out from behind the Moon as a bright spot on the dark side of the Moon. It was quite dramatic, and it happened right on time. The students cheered and clapped. I will probably remember that moment the rest of my teaching career.
So, if you get a chance, try to get out and see the occultation. This one won’t be quite as dramatic as the one that I saw over two decades ago because it will be happening after sunrise (the one that I saw was during twilight, and it was much easier to see than this one will be). Still, it should be impressive in binoculars or small telescopes.
-Astroprof
Images created using Starry Night Enthusiast
Jason Sickles on April 22, 2009 at 10:07 am: 1
Thanks for the insight. We paired your explanation and one of our photos in a post on our Weather blog (www.dallasnews.com/weatherblog).
Carolyn on April 22, 2009 at 11:06 am: 2
I saw it at 5:45 this morning and you could only see the crescent moon. Venus looked like a very bright star below the crescent. It was very dramatic against the dark sky.
Astroprof on April 22, 2009 at 12:09 pm: 3
Jason, thanks. I’m glad to be of service.
Carolyn, I’m glad that you enjoyed the sight.
John Hogan on April 22, 2009 at 12:10 pm: 4
I live in El Paso, Texas and saw the moon and Venus getting close and ran to get my camera tripod. I watched it in total amazement for over a half hour and although my lenses of my camera aren’t as strong as the telescopic photos in the above article, I still got some amazing shots of this occurrance. Astonishing visual.
Marlene Fellows on April 22, 2009 at 10:16 pm: 5
I live 100 miles from Sanderson Tx in Del Rio. I saw it perfectly at 0630 this morning. My husband goes to work at 0545. I called him as I knew he would have seen it. He does his devotional EVERY Day walking across a flightline looking up at God’s sky. He said it was Venus. Having been a cowboy working on a ranch he has looked up and seen many stars and planets. It was awesome.
Phillp Uttz on April 23, 2009 at 12:44 am: 6
Can I send you a couple of photos that I took this morning? I was at Mt. Wilson, CA. The event was stunning.
Astroprof’s Page » Occultation Photographs on April 27, 2009 at 7:08 pm: 7
[…] week, I wrote about the occultation of Venus. You can read that posting to find out more about the event. I got several comments on the […]