Letter to the Editor

Did you miss the occultation?

Tuesday, April 15, 2008

Boy, I hope you had the opportunity to watch a just-passed three-day old moon and the Pleiades star cluster last week. It was a beautiful, clear evening just made for stargazing. The weather was a little cool but nothing a nice jacket or a heavy sweater couldn't handle.

The occultation, that is what it is called, happened when the moon slid in front of the stars of the Pleiades star cluster and blocked their view for a time.

With a good pair of binoculars I had a ring-side seat for a great astronomical show.

At about 8 p.m., local time, the moon passed in front of fourth magnitude Taygenta on the northern edge of the cluster. From this part of the world that is about all of the cluster the moon covered.

At first I thought the moon was going to go head-on into the cluster but the more I watched I discovered this was going to be a slanting slide past. Taygenta was just covered by the extreme dark edge of the moon and was covered for only 28 minutes.

This was a good opportunity to see an example of earthshine too. Earthshine is the light of the sun bouncing off the Earth and onto the surface of the moon. If there can be moonshine (not the drinkable kind) why can't there be earthshine?

Earthshine is best visible just after the moon is new and is in the thin, growing crescent phase. It gives an eerie light coloration to the part of the moon the sun is not shining directly on. It is like you can see the moon but it is not equally lit. Astronomers call this effect the new moon in the old moon's arms.

SKY WATCH:

The full moon on Sunday, April 20, will block out most viewing in the early evening for a few days. You should, however, have no problem viewing the moon visiting the bright star Spica in the constellation Virgo, the Maiden on Friday, April 18, and Saturday, April 19.

It will be closer on Saturday, only about four degrees away. Saturn and the bright star Regulus in Leo, the Lion hold sway high in the south in the early evening with Mars glowing a dull red to their right in Gemini.

The constellations of summer are rising about 2 a.m. along with the bright planet Jupiter. It is just to the east of Sagittarius and the glowing river of stars that is the Milky Way.

NEXT TIME:

More astronomical blathering.

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