Astronomical Potpourri in June
May 2006 :
Note: This article may contain outdated information
This article was published in the May 2006 issue of The Skyscraper and likely contains some information that was pertinent only for that month. It is being provided here for historical reference only.
Many of us have been waiting for Jupiter to clear the tree-tops of our favorite observatories. We've observed Saturn all winter and early spring, and now we're ready to turn our gaze toward the largest planet in our solar system. I will pen a more detailed column about Jupiter next month, but for now I simply want to entice you to visit Seagrave Observatory any clear Saturday night, or Ladd Observatory any clear Tuesday night, for a great view of this dynamic world.
We hope to see a fairly new feature in Jupiter's cloud tops. It's called "Red Jr." This new spot formed from the merging of three spots in recent years. However, more recently it has turned red, much like its bigger brother, the Great Red Spot.
The Full Moon of June occurs on the 11th at 2:03 pm. While Full Moons' carry a wide variety of names, many of the more familiar ones come down to us from Native American culture. June's Full Moon is no exception, for it is called the Strawberry Moon. See accompanying artwork from Ruth Flanigan, wife of my best friend and kindred spirit Bill Gucfa. He's a proud member of the Mohegan tribe.
About 40 minutes after sunset you can spot a cluster of stars 20 degrees or so above the western horizon (an adult fist held at arm's length measures 10 degrees of sky, so two fists will get you in the general area). This cluster is called the Beehive. At the beginning of the month you can spot Saturn just below this sprinkling of stars. Continue to watch as the month progresses, for reddish Mars, closer to the horizon at the beginning of the month, will begin to slide eastward towards the Beehive and Saturn.
On the 15th Mars is right in the middle of the cluster, and two nights later on the 17th he will pass within just over a Full Moon diameter of Saturn, which by then will have also moved further eastward relative to the cluster. If you have access to a computer planetarium program you can speed up time and watch Mars and Saturn behave as bees as they buzz the Beehive cluster and each other. A thin crescent Moon slides by Mars on the 28th, making for a beautiful twilight spectacle.
Mercury is often a difficult planet for us Earth-bound amateur astronomers to observe because it never strays very far from the Sun's glare in our sky. Only when Mercury appears east or west of the Sun, as viewed from the Earth, do we have an opportunity to view this world.
During these favorable elongations, as they are called, Mercury can be seen in the western sky after sunset, or in the eastern sky before sunrise. Despite its elusiveness, Mercury's upcoming elongation in the western sky after sunset will provide us an acceptable view. On June 20, within a half hour after sunset, you should see Mercury with your naked-eye about 15 degrees above the sunset point.
Should you have a telescope you can train on Mercury you will notice that the planet is 39% illuminated, like a waxing crescent Moon just before First Quarter. If you begin observing Mercury earlier in the month you can watch him quickly go through phases like our Moon. For instance, on June 6, though Mercury will be much lower in the sky, the planet will be 66% illuminated. On the 14th it will be 50% lit.
After reaching its highest point in the sky on the 20th, Mercury will begin to slide back towards the horizon and the Sun. As it does so the percentage of illumination will decrease and the image size will become larger as it swings a little closer to the Earth. By July 1st Mercury will be a large thin crescent 20% lit and low in the western sky during twilight.
Be careful at all times when you search for Mercury. Don't begin searching until after the Sun sets. You couldn't pick it out in the bright sky anyway, so don't be tempted to point your telescope or binoculars anywhere near the Sun.
And finally, the Summer Solstice occurs on June 21st at 8:26 am. Note how far north along your horizon the Sun rises and sets. Also note how high the Sun is in the sky at local noon time. That's the time when the Sun crosses your longitude and is due south of your location on the Earth's surface.
Keep your eyes to the skies.
