Our Window on Nature

With vision so sharp it equals that of a man with binoculars, a bighorn ram gazed down the mountain. In the open vistas favored by this species, keen eyesight far overshadows the need for acute hearing or sense of smell, so we were certain the animal eyed us long before we spotted him. Even so, he seemed more curious than alarmed.

We hiked up Truchas Peak in New Mexico’s Sangre de Cristo Mountains especially to see bighorn. As in any designated wilderness, if you want to visit the critters, you walk. Gradually, our eyes picked out several more bighorn, less visible against the rocks. Oh, for their surefootedness as they ambled down the almost-vertical slope. We couldn’t believe they were actually approaching us. Could it be that there were enough hikers along here to turn these wild, free creatures into panhandlers? Surely not.

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Kaye still remembers the first time she saw a live tarantula. She was glancing out the front window of our California home when an enormous, hairy spider crawled past the front of the house. It was huge. Conditioned by adventure movies to believe that tarantulas are both deadly and intent upon attacking innocent people, Kaye allowed the critter to continue right on down the road.

Her next tarantula sighting wasn’t until after we’d begun traveling, and by that time we knew enough about spiders to realize that although a chase scene featuring a tarantula may make good theater, it doesn’t represent the facts. These spiders aren’t pretty, but neither are they hostile; they’re simply fascinating.

Even decades after the event, we can make certain assumptions about Kaye’s early tarantula sighting. She probably saw the spider in late summer or early fall; it probably was an adult male on the prowl in search of a mate; and in all likelihood it wasn’t as huge as it appeared. So, since tarantula season is here and since at least some of you who are reading this column will be traveling into the spiders’ territory during the months ahead, we’ve compiled a few facts about these hairy spiders. (Read the rest …)

Vision at night is difficult at best, whether you are watching wildlife or searching the sky for meteor showers. But it always seems you need just a bit more light to check the settings on your camera. Or to find the position of a constellation on your star map.

The problem is that flipping on a flashlight ruins your night vision. It takes about 15 minutes for your eyes to adapt to the dark and see detail, and only a second or so of bright light to undo the process. Fortunately there is a solution.

Dim red light has only a minor effect on our vision at night, so a red flashlight allows you to check what you just wrote in your notebook and still look up to see the animals that have better night vision than we do. And the animals are less disturbed by red light.

I’ve seen advertisements for red flashlights, but a less expensive solution is to cover a light source with red cellophane or plastic. When I couldn’t find any locally, I bought a transparent reddish-pink file folder at a stationary store. Two layers did the trick. Enough light to see, but not enough to ruin my night vision.

One of the Southwest’s most attractive plants, the Sacred Datura, is also one of its most deadly. Every now and then newspapers carry the grisly story of someone who, after experimenting with a species of Datura, wanders for days through desert delusions until brought down by the searing heat. While seeking heavenly visions, the user ignored the possibility that he might be creating his own physical hell. For along with the hallucinogens, this plant packs a payload capable of ending the search.

Otherwise known as thorn apple and Indian apple, the Sacred Datura is closely related to jimsonweed and is part of the nightshade clan, a worldwide plant family encompassing both reputable and notorious members. The most famous of these are tomatoes, eggplants, hot and sweet peppers, and potatoes. Of course, these plants were also considered poisonous in the past. Datura favors the less beloved branch of the nightshade family, the one implicated in murder, witchcraft, seductions, and orgies. (Read the rest …)

Next Tuesday morning (August 28^th) we’ll get to see the second total lunar eclipse of this year. Early in the morning the moon will begin its passage into the shadow of the earth.

Once a month (actually every 29 ½ days) the sun, earth, and moon line up to bathe our planet in the maximum amount of moonlight, allowing moon-watchers to view all the ridges and craters on the near side of the lunar surface. But it’s only several times a year when the alignment is correct for the moon to actually enter the shadow cast by our planet.

During partial eclipses it looks as though a bite has been taken out of the moon, and that’s the way it will start on Tuesday morning. However, since this will be a total eclipse, the entire moon will pass into the shadow region, and for an hour and thirty-one minutes the sun’s light will be blocked by the earth. But the moon doesn’t actually disappear.

Even without direct light the moon will still be visible. As the sun’s rays pass through the earth’s atmosphere, they are slightly refracted (bent), and depending upon the amount of cloud cover and dust in the air, these curving rays will tint the moon in some shade of copper or red. The color is caused by the same phenomenon that gives us beautiful sunrises and sunsets. But this time the color is picked up overhead by the darkened moon.

An eclipse is one of the best times to study the moon. As the shadow of the earth rushes over the lunar surface, it will help highlight the various moon features. A pair of binoculars will make your view even better, and if you do a bit of preparation you’ll know where to look and what to expect.

You can print out a moon map from Space.com. Just point your computer to http://www.space.com/images/skywatchers_moon_map.gif and send the image to your printer. There is also a beautiful detailed topographic map of the moon, showing the seas, craters, and mountains at http://cseligman.com/text/moons/moonnear.htm.

The best show will be on the west coast, starting at 1:51 a.m. Pacific Daylight Time, with the total eclipse starting about an hour later. Add an hour for each time zone as you move east. Unfortunately on the east coast the sun will rise about half-way through the performance. The entire display will last a little over three and a half hours.

The moon image (with added labels) was taken from the Distant Suns computer program. Distant Suns has both a free and a commercial software program that will display the night sky right on your computer. It’s what I use to help me explore the heavens. Check out their website at http://www.distantsuns.com/.