Revisiting our old celestial friends

With the advent of warmer spring evenings it is time to revisit our old friends, Ursa Major and Ursa Minor, the Big and Little Dippers.

As I have said before, the pair are not really constellations in the full sense of the word, they are asterisms or star patterns which can be recognized in their own right.

At present the Big Dipper can be seen almost overhead at about 8:30 p.m. local time, with the dipper appearing upside down. In folklore the upside down dipper means the spring rains will be pouring out of the dipper onto the earth.

There are five Messier (the French comet hunter) objects found in the area of the Big Dipper, all require a dark site and binoculars or a telescope to see them as they are below the 10th magnitude in brightness. Also a total of 50 galaxies, or island universes, can be found in the area.

Using the outer two stars of the dipper's cup, Merak and Dubhe, trace a line to the north (down) to find Polaris, the North Star, which is the end star in the handle of the Little Dipper. The smaller dipper's handle extends in the opposite direction of its bigger brother.

Both asterisms are circumpolar, that means they circle Polaris, the North Star and never set below the northern horizon so they are visible all year long.

The Big Dipper is a useful tool for finding other constellations besides Polaris and the Little Dipper. Using the handle, follow the arc to the star Arcturus in Bootes, the Herdsman then continue on to find Spica, the brightest star in Virgo, the Maiden.

Reverse the line from Merak and Dubhe, the pointer stars in finding the North Star, to find Regulus, the brightest star in Leo the Lion. Next find Phecda, the bottom star of the cup nearest the handle and draw a line across the cup to the top pointer star Dubhe to put yourself in the area of Capella, the brightest star in Auriga, the Charioteer.

To find Gemini, the Twins, start at Megrez, the star where the handle joins the cup. Go across the dipper to the bottom pointer star, Merek, and continue the line to find the twins.

The Big and Little Dippers are good places to spend some time with a pair of binoculars or a telescope, especially looking at Mizar and Alcor, the double star at the bend in the handle of the Big Dipper.

On other non-astronomical matters, Nebraska is about to have its first astronaut in space. With the launch of the space shuttle Atlantis set for June 8, astronaut Clay Anderson will take his place as a member of the Expedition 15 crew as a flight engineer replacing NASA astronaut Suni Williams who has been aboard the space station since December 9 of 2006.

Anderson is a native of Hastings, Neb., and this will be his first mission into space. He is scheduled to stay until the STS-120 mission in October of this year when he will return to Earth.

There will be more about how to locate and observe the space station as it passes overhead as the launch date draws closer.

SKY WATCH: Full Moon, May 2. The modest Eta Aquarid meteor shower can be seen from now through May 12 with peak shower activity occurring on the morning of May 5 at about 4 a.m. MDT. Look in the east southeast for the dim constellation Aquarius, the Water Bearer, located just below the square of Pegasus. Although the just past full Moon will interfere somewhat with viewing the shower, a meteor every few minutes is possible. The Eta Aquarids are leftovers from Halley's Comet. Venus in the west and Saturn in the south are visible in the early evening sky. After midnight Jupiter rises in the east. Mars and Uranus can still be seen in the early morning sky. Use binoculars and look in the east southeast about an hour before sunrise. Reddish Mars will be below and to the left of greenish Uranus.

Next time, stargazing tips.