L ike many avocations, stargazing can be a year-round activity as any clear night offers interesting things to see. Regardless of the season, there will always be stars and constellations, and often the Moon and one or more planets.

Yet the seasons do affect stargazing, and notably summer verses winter. A most obvious difference relates to the objects available for viewing since the winter and summer night skies feature different constellation shows.

But first, let's consider some other seasonal differences.. Being a cold weather wimp, I confess to preferring summer stargazing. No matter how lovely the winter might be, I can't enjoy viewing it if I'm shivering and my feet and hands are aching cold - so I much prefer warmer weather.

There are, however, some disadvantages to summer stargazing, like summer's later sunsets and earlier sunrises which make for shorter nights. While winter nights offer upwards of 14 hours of darkness (at our latitudes), summer nights can be as short as 10 hours. And there's the inconvenience of darkness coming so late in the summer. With daylight saving time, summer star parties can't get going good before 10 p.m., and that's kind of late for kids and old codgers like me.

And then there are the critters - especially mosquitoes which seem more active in the summer. You'll want to have bug spray available, but be careful how you use it at star parties. Never apply spray around telescopes or binoculars as the chemicals can damage the optics.


Snakes and other animals are more active in the summer, so if you're stargazing in a grassy area, be aware. I've never encountered a snake while observing, and hope I never do, but one of my stargazing buddies, Willie Strickland, had a startling encounter at our astronomy club's observatory.

As he was about to unlock the observatory door in the dark, he dimly saw something that made him step back. With his flashlight, he saw a long snake climbing up the door casing on its way to devouring some bird eggs. In our desire to live compatibly with nature, we had left undisturbed a bird nest in the entrance way, not being aware of its attractiveness to chicken and rat snakes. Fortunately, Willie wasn't bitten, but he was certainly rattled by the experience.

Another time we saw a tarantula spider ambling across the viewing field, but he was just as anxious to get away from us as we were to have him leave. We've also encountered skunks and other critters, but they didn't seem concerned about us since we didn't make threatening gestures toward them.

In far west Texas, the Davis Mountains and Big Bend National Park are famous for dark skies, making them popular destinations for stargazers, but there are certainly potentially hazardous inhabitants out there. Black bears and mountain lions come to mind immediately, but fortunately they are generally people-shy and rarely seen. Since my first trip to the area in 1970, I've been back 30 or more times, and I've never seen a bear or mountain lion.

But I've seen many peccaries, also known as javelinas. (Peccaries are often erroneously called javelina hogs, and while they bear some resemblance to hogs, they are not in the pig family.) Although not particularly aggressive, they have sharp teeth and can be dangerous if one gets between them and food. They wander around in small bands, especially at night, and often come right through campsites searching for food. I've never been accosted by them, but I've seen the ruins of their determination to get at food in tents and coolers, and they've been known to kill pet dogs left out on a leash. So, again, it's good to be aware of one's surroundings while stargazing.

But enough of these earthly matters - let's look at the summer night sky. As Earth orbits the Sun throughout the year, the night sky changes with the seasons as different parts are visible at different times of the year - the key words here being "night sky." Every day of the year, all the stars ever visible from any given location come into the sky - some are up at night and can be seen, while the rest are up during day but hidden by sunlight. So when we speak of the summer sky, we mean that part of the sky that's up during the early evenings of summer.

The Milky Way, the galaxy of which we are a part, stretches all the way around the night sky, so part of it is up every night of the year - but the summer sky gets the brightest part. Galaxies are huge disc-shaped clusterings of billions of stars swirling around a central bulge where stars are far more concentrated.

The Milky Way's center happens to be in the heart of the summer sky, in the direction of Sagittarius and Scorpius, the signature constellations of summer. Although intervening cosmic dust and gases prevent our actually seeing into the heart of the galaxy, it is still the brightest and most star-rich area of the Milky Way. Hundreds of globular clusters, special type of star clusters akin to mini-galaxies, swarm around the Milky Way's central bulge, thus most of them are also seen in the summer sky.

But while the summer sky has the better Milky Way, the winter sky has a somewhat greater concentration of the brightest stars, called 1st magnitude stars. Sagittarius and Scorpius have but one 1st magnitude star between them, and the entire summer sky has just seven scattered across the sky. The winter sky has nine 1st magnitude stars, seven of which are bunched within the Great Winter Arc Region. The winter sky also contains Sirius and Canopus, the night sky's two brightest stars.

There are other seasonal differences, but it should be pretty clear that the seasons are not the same when it comes to the night sky and stargazing. In upcoming Stargazer columns we'll be highlighting the major constellations of summer.

Stargazer appears every other week in The Lamar Ledger. Paul Derrick is an amateur astronomer who lives in Waco. Contact him at 918 N. 30th, Waco, CO 76707, (254) 753-6920 or paulderrickwaco@aol.com. See the Stargazer Web site at stargazerpaul.com.