Scanning the skies for the Irish constellation

Wednesday, March 5, 2014

Now, let's see, where were we? Oh yes, looking south at Orion, the Hunter. Which reminds me of a question someone asked me last week. Which constellation is the Irish constellation? Why O'Ryan, of course. Now that St. Patrick's Day is a little more than a week away, you can use that.

Continuing with our sky survey, about an hour after local sunset, slide your gaze slightly to the left of Orion to find the bright planet Jupiter. It is the largest planet in our solar system and is a gas giant.

A gas giant is a planet made up of gas, not solid substances. The other gas giants of the outer solar system are Saturn, Neptune and Uranus. Astronomers believe that while the gas giants may have a rocky core, their atmosphere is made up of gasses like ammonia, nitrogen, helium, methane, water vapor, and hydrogen sulfide.

Jupiter is currently between the feet of the Gemini twins. The just past-first-quarter moon will pay Jupiter a visit on the evenings of March 9 and 10.

Following the ecliptic -- the line that the Sun, moon, and planets follow through the sky -- to the left we next find the moon visiting the small, almost invisible constellation Cancer, the Crab. The only attraction here is the small open star cluster M-44, also called The Beehive. In binoculars you will see why the stars look like a buzzing swarm of bees.

The three brightest stars of Cancer are all about fourth magnitude, so are difficult to see unless you have a very dark-sky location from which to observe. They look like an upside down "Y" or the peace symbol without the circle.

If you want to have some fun on the evening of March 12, be outside about a half hour after local sunset and find the moon and observe it with your binoculars, even a small telescope would be nice.

The moon will be in front of another Messier-named star cluster, M-67 or the King Cobra.

The lunar body will be covering about half the cluster. Watch as the moon moves away revealing the rest of the cluster's stars. Keep watching until almost 9:00 pm local time when the moon will cover, or occult, a star, 60-Canceri.

The star will reappear on the other side of the moon about an hour and a half later. Occultations are fun to watch, especially if a planet is involved. Last week the moon occulted the planet Saturn, unfortunately you would have needed to be in Australia to observe it.

While you are out watching the moon shift your glance to the north to find that the Big Dipper is standing straight up on its tail with the bowl of the dipper high overhead.

Another event to watch on the evening of March 12, is the moon traveling just under the star Acubens (Alpha Canceri). As the evening progress, the moon will seem to float just below and pass to the left of the star.

SKYWATCH: Full moon, Sunday, March 16. At 11 p.m. on the evenings of March 18 and 19 the moon will be in the vicinity of the star Spica and the planet Mars; Mars is the bright red one to the upper left. Mars is getting brighter each week and will be at opposition--opposite the Sun in the sky and closest to Earth on April 8. Now is a good time to be aware of the "Great Mars Hoax" that pops up every two years when Mars is at opposition. It says that Mars will be as big as the full moon. Be warned, it isn't going to happen, it wasn't true in 2003 when this hoax started and it won't be true now. It will be bright and nice to look at, but that is all.

NEXT WEEK: Leo, the Vernal Equinox, and more astronomical blathering.

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