The great procession in the sky
Thursday, April 19, 2012
Well, all the characters that made the last few weeks astronomically exciting have left, or are in the process of leaving the evening sky.
Jupiter has one more close meeting with a very slender crescent moon on the evening of Sunday, April 22, after which by the first week of May it will be gone from the evening sky.
The moon will be just a little past one day-old so it should be good for a nice display of Earthshine, or the light of the sun reflected off Earth's surface onto the face of the moon.
There is a light, shadowy image of the whole moon with just a thin bright crescent lit by the full light of the sun. Some have called it "The old moon in the new moon's arms." To get the full effect, use binoculars.
After meeting Jupiter, the moon moves on to play tag with the Pleiades star cluster in the constellation of Taurus, the Bull on April 23rd, then on to meet Venus the next day.
Venus is still rising higher in the sky and will continue to do so until the first week of May when it meets the star Elnath.
Elnath is shared by two constellations, Taurus the Bull, and Auriga, the Charioteer. More about them later.
Since we have been concentrating on individual characters of late we have kind of neglected the bigger players on the celestial scenario, the constellations.
The boys of winter are on their way out and the boys of spring are definitely making their presence known.
First we have the vernal leader, Leo, the Lion.
Leo, like Orion, is one of the few constellations that actually looks like what it is supposed to be.
Right now Leo can be found high in the sky due south about an hour after sunset. Currently bright, reddish Mars is located slightly left of the bottom of the upright backward question mark that indicates the head and mane of the lion and the bright star Regulus that is the dot below the question mark.
The rest of him, the hindquarters, is a triangle of stars just to the left.
Just to Leo's right is the small dim constellation of Cancer, the Crab. The stars of Cancer are very difficult to locate so a very dark-sky location is needed.
To see the shape of Cancer, imagine what the three-armed peace symbol from the '60s looked like, or perhaps the hood emblem on a Mercedes-Benz automobile.
One of the objects to look for in Cancer is the very nice star cluster M-44. It is located at almost dead center where the three arms come together. It is a great sight in binoculars, and really super even in a small telescope.
If you are having a hard time finding it, wait until Saturday, April 28, when a first quarter moon will be just below it. Put the moon just out of sight on the bottom edge of the field of view and M-44 will be just beyond the field of view at the top. Just move the field up a little, and there you will find it.
More spring constellations next time.
SKY WATCH: New moon, April 21. If you want something to do in the wee hours of the morning, try being outside in a very dark place in the early hours after midnight on April 22. If you are looking about half-way up the eastern sky you might be able to catch a few of the meteors from the Lyrid meteor shower. The hourly rate is about 20.
Something else you might want to be looking for are the "April Fireballs." Astronomers think they might be part of a branch of the Virginid meteor shower. They are very large, bright, blazing streaks of light from some space rocks. A normal meteor is about the size of a grain of sand, these fireballs could be the size of a medium rock. There are not many of them per hour and the shower lasts for about two weeks beginning April 15.
NEXT WEEK: More spring constellations, and more astronomical blathering.