Catch a glimpse of earthshine

Thursday, July 19, 2012

I hope many of you had the opportunity to observe the conjunction of the moon, Venus, Jupiter, and the star Aldebaran last Sunday morning before sunrise.

I have said many times, I am not a morning astronomer, unless there is something worth getting up for, and this was definitely worth getting up for.

In addition there was a marvelous display of earthshine, the light of the Sun reflected off Earth's surface back onto the moon giving a ghostly image of the entire surface of the lunar face.

If you did miss it, fear not, there will be another opportunity for a view of earthshine on July 23 and 24 when a six-day old moon makes a pass at Mars and Saturn. It won't be quite as spectacular as it was on Sunday, but you will get the idea.

Speaking of Mars and Saturn, while we have been focused on the early morning skies, our old friend Mars has been making an end run toward Saturn in the early evening hours.

If you have the opportunity some evening this week when the sky is good and dark, look for Mars. It is the red dot a little more than a fist-width above the western horizon in the western end of Virgo the Maiden.

Keep a watch on Mars as it moves eastward against the background stars toward sister planet Saturn on the other end of Virgo. On August 12, it will pass directly between Saturn and the star Spica.

Now, to the matter at hand. July is always a great month astronomically speaking. It means the return of our old friends Scorpius and Sagittarius and the southern end of the Milky Way.

This area is the happy hunting ground for star clusters, nebula, and all kinds of faint fuzzies that are fun to hunt down.

Right now, Scorpius and Sagittarius straddle the meridian, the imaginary line the indicates due south in the sky.

Scorpius is one of the few constellations that actually looks like what it is supposed to be, a scorpion. Three stars in a row for the head, and a long fish hook shape for a body that extends down almost to the southern horizon.

Just below and left of the three head stars is a red star, Antares, the "Rival of Mars." It marks the heart of the beast.

If you want to get started on your "faint fuzzy" hunt, Antares is the place to do it. Put Antares in the center of your binocular field of view, and just below and right (at about the four o'clock position) is the nice little globular star cluster M4, the Cat's Eye cluster.

Next put the "stinger" star in the center, then move the view up and left until the stinger star is on the extreme lower right side. On the opposite side is another star cluster, the open cluster, M7, also known as Ptolemy's Cluster.

Move M7 to the eight o'clock position and at about two o'clock is another open cluster, M6, the Butterfly cluster. Look closely to see if you can find out why it was called that.

Well, that will get you started. If you just scan around the area you will find lots more clusters and nebula, some of which we will talk about next week.

SKY WATCH: New moon, today, July 19. Mars and the moon, July 24, Saturn and the moon July 25 both about an hour after sunset.

NEXT WEEK: Sagittarius, the Summer Triangle and more astronomical blathering.

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