Greetings, stargazers.

I should warn the reader now that I dislike daylight saving time.

Now that we are past the equinox, the sun is north of the equator, warmer weather is coming and days will be longer than nights for the next six months, etc. These changes appear all the more abrupt because of what I think was the early arrival of daylight saving time. Not only do I have to start the day in darkness again, I have to wait an hour longer before the stars come out.

A few months ago, I discussed how bluer light scatters more easily in our atmosphere. This is why the sky is blue and why many LED street lights are not as good for keeping Durango skies dark. Increased light scattering from short wavelength light is also why green laser pointers are popular with astronomers for pointing out objects in the night sky. Light from green lasers will scatter in the air, so their pencil thin beams are easy to aim and easy for others to see. Red laser pointers just won’t scatter, or be seen.

Green lasers’ enhanced visibility is also an issue. An increasingly serious problem is the careless, or worse, malicious use of green laser pointers aiming toward aircraft. To a pilot sitting in a dark cockpit, a brief flash from one of these is worse than a flash bulb going off. Temporarily blinding someone responsible for multiple lives is unfathomable.

I have witnessed careless users pointing at the night sky willy-nilly, with never an intention to point at aircraft. Unfortunately, an accidental hit is just as serious as an intentional hit. As with a gun, only fire when you know your target and can take careful aim.

This month

Venus, high in the western sky after dark, is remarkably bright. Jupiter, the second brightest object, is now in Cancer.

Cancer is one of the dimmer constellations in the sky, situated between the much more prominent Gemini and Leo. Take advantage of Jupiter’s presence to successfully locate and identify Cancer’s outline.

Near the middle of Cancer is Messier object M44, also called Praesepe, or the Beehive cluster. It is an open cluster visible to the naked eye as a faint fuzzy patch and was known to ancient astronomers. It was one of several objects observed through a telescope by Galileo, who saw at least 40 stars. Modern instruments can identify more than 1,000 member stars. M44 is one of the most rewarding targets for binocular and low power telescopes because of the number of easily resolved stars.

So wait that extra hour for darkness and be careful when you point out M44 to your friends.

Charles Hakes is an assistant professor in the physics and engineering department at Fort Lewis College and is director of the Fort Lewis Observatory. hakes_c@fortlewis.edu

Useful links

Astronomy picture of the day: http://apod.nasa.gov/apod/

An Astronomer’s forecast for Durango: www.cleardarksky.com/c/DrngoCOkey.html?1

Old Fort Lewis Observatory: www.fortlewis.edu/observatory

Four Corners Stargazers: http://groups.google.com/group/Four-Corners-Stargazers