This installment of an ongoing feature looks at the necessity of keeping warm in winter, record low temperatures, and the sights sky watchers can expect to see in December 1994 and throughout 1995.
I believe my first article for MOTHER EARTH NEWS was in 1982. Through the early 80s I contributed a major section on astronomy for the magazine's almanacs of that period. And during the entire decade I was writing one or two articles on sky sights and phenomena every year.
I've always enjoyed the magazine, and its people — I remember with great fondness the many talented and friendly staff members I've worked with here over the years. No other magazine does what MOTHER EARTH NEWS does so well. Here's to another 25 down-to-earth, straight-from-the-heartland years for this magazine, more indispensable than ever!
With the winter season upon us, keeping warm becomes an imperative. Cold weather in most parts of the United States has the potential to be more than uncomfortable — it can kill and maim. The body attempts to conserve heat by constricting blood vessels near the skin and by shivering. When these mechanisms are insufficient, frostbite and hypothermia can be the result.
Frostbite is an actual freezing of the skin, a formation of ice crystals that can damage living tissue. People usually recover completely from the milder cases, but severe frostbite can lead to permanent and painful sensitivity to cold or even to death of tissue requiring amputation of the affected extremities.
Hypothermia can be even worse. It is the state the human body enters when its core temperature drops below about 95°F. A person becomes disoriented, at first shivering violently but then less. The next stages can be unconsciousness and death.
Most people know that a large fraction of the body's heat escapes from the head and neck, so it is crucial to keep these covered. This is particularly true when the windchill reading is low (the wind carries away your escaping body heat much more rapidly), so be sure to consult your TV or radio weather forecast for this figure. Also consider how active you will be outside. Fatigue makes the body more susceptible to the cold, but moderate exercise can keep you warmer — a Canadian study shows that a person who will be standing still outside should dress for temperatures 20 to 30 degrees colder than someone who is taking a brisk walk.
Caffeine and tobacco should be avoided because they restrict circulation in the extremities. Alcohol is even worse because it dilates capillaries in the skin, causing heat loss. And believe it or not, drinking water can have a major positive effect in keeping you warm in winter! My astronomy colleague Alan MacRo bert turned up the very little-known fact that dehydration is a major cause of chills and other bad feelings in cold weather. Cold winter air is usually very dry (the cooler air is, the less moisture it can hold), but cold suppresses the body's thirst mechanism. So you tend to drink less than you should. And when the body gets low on water, it tries to conserve fluids by reducing circulation to the
How cold does it get in Alaska? The all-time low temperature is minus 80 degrees Fahrenheit at Prospect Creek Camp on January 23, 1971. Think of it: that temperature is to zero degrees Fahrenheit what zero degrees Fahrenheit is to a typical summer afternoon. Still, you might say, Alaska is up there near the North Pole. Surely, down here in the "lower 48," we never approach such levels of incredible frigidity. Yes, we do. On January 20, 1954, the temperature in Rogers Pass, Montana, nudged minus 70 degrees Fahrenheit.
Even the warmest states have had some amazingly low temperatures. Florida's coldest on record is Tallahassee's minus 2 degrees Fahrenheit on February 13, 1899 (the southern tip of Florida, excluding the Keys, has experienced freezing weather and snow on the rarest of occasions). The official record low for Hawaii is (can you believe it?) 12 degrees. There is a catch with the Hawaii record, though. The temperatures down at sea level in that tropical land basically never drop below the 50s, but it can get much colder up on the mountains which can have snow down to about 5,000 feet elevation.
Is there anywhere that temperatures can get colder than in Alaska? Siberia can get a little colder. But there is one place on Earth that is much more frigid: Antarctica. Earth's all-time record low was set at Vostok Station in Antarctica in 1983: -128.6 degrees. The average temperature on Pluto is -382 degrees. And the temperature of absolute zero, the point at which all molecular and atomic motion stops, is about -460 degrees.
December is the stormiest month for the United States and, for many parts of the country, the cloudiest. It doesn't get any cloudier than in the Northwest at this time of the year: if you average the total amount of time and area of sky that are clouded in Portland in a typical December the figure you get is 90 percent cloudy! And January is not much clearer for the rest of the States.
Fortunately, the universe comes to our rescue with the year's brightest evening stars to gladden the heart when the clouds do break up. The brightest constellation, Orion, and the brightest star, Sirius, are visible, trekking from east to south during the course of December and January evenings. Other bright star patterns like Taurus and Gemini add to the luster of this part of the heavens.
This winter we also have a bonus for early risers: Venus at its best and brightest as the morning star. This planet easily outshines all other points of light in the heavens and can easily be detected with the naked eye until well after sunrise on a clear December morning! Venus is involved in several beautiful pairings with the Moon and Jupiter these next few months.
The big astronomical sights in 1995 should be pairings and groupings of the planets for the naked eye and rare, dramatic appearances of Saturn's rings and perhaps Jupiter's clouds for telescope users. Of course, there are always unpredictable events—perhaps a bright new comet or great northern lights display — that could steal the show!
Planets. In 1995, Venus starts the year in the southeast before dawn, shining bright and high (and showing a half-moon phase in telescopes). But it gets lower in dawn most of the year and does not emerge in the evening sky until November, when various close conjunctions are followed by a low but tremendous Thanksgiving gathering of Venus, Jupiter, Mars, and the Moon. In 1995, the dimmer (usually lower Mercury) is best seen low in the west, about 45 minutes after sunset, for a week or two around January 19 and May 12 and low in the east for about 45 minutes before sunrise, for a week or two around October 20.
The best planets for 1995 are Saturn, Jupiter, and Mars. Mars comes closest to Earth about every other year and 1995 is one of those years, though its close approach in February is one of the least near possible. Still, Mars will be a beautiful sight among the stars of Leo's bright head and chest, and a medium-size telescope will show some surface details on it. Jupiter is in and near Scorpius this year and shines biggest and brightest in May and June, when it is visible just about all night long. The big question is whether the incredible dark spots formed on Jupiter last July by the impact of a shattered comet will endure and continue to be a once-in-a-thousand-year marvel to see in small telescopes.
We can be sure that Saturn will put on an unusual show for telescopes. This year the magnificent rings will, at various times, seem to be a bright line, a dark line, and even nonexistent as their stupendously thin sides are turned toward Earth for the first time since 1980.
Eclipses and Occultations. This year's eclipses are meager for the United States, but there are a series of wonderful "occultations" — hidings — of the star Spica by the Moon. In the western states on April 15th, viewers can watch a small partial eclipse of the Moon at the same time that the Moon hides Spica! All of the country sees some of that eclipse. The other two eclipses visible are so slight — even from the limited part of the country that sees them — they are hardly worth mentioning.
Meteor Showers. Meteors, also called "shooting stars" or "falling stars," are bits of space rock that make streaks of light in the sky when they burn up from entering Earth's atmosphere at immense speeds. A "meteor shower" occurs when Earth passes through a denser band of this debris in space and we see increased numbers of meteors appearing to shoot out from a particular point among the stars. In 1995, viewing of August's Perseid meteor shower is badly hampered by bright moonlight. But evening observations of the 1995 Geminid shower's peak will be moon free, the Leonids of November and Orionids of October will not be too badly bothered, and the peaks of the Quadrantids in January and Delta Aquarids in July can be watched with no Moon in the sky.