The holiday season, a two-week period of buying, giving, and general revelry, is now upon us. I must confess that I view this time of year with a mixture of joy and sadness.

We celebrate, each in our own way, the joy of life. However, one sad fact intrudes. During the holiday season, more people in the United States die than at any other time of the year.

According to a study by David Phillips and other researchers at the University of California published in the journal Social Science & Medicine, the peak death season centers on the two-week period around Christmas.

That cycle traditionally ends on New Year’s Day as old Father Time, the ancient god Cronus, the Reaper, scythe in hand, harvests the old year. It is therefore fitting that New Year’s Eve is the time of the year when our collective consciousness is fixated on time and its passage.

Time, after all, is the most precious commodity we possess, because we are given so little of it.

As we age, we become far more aware of time’s inexorable flow. When we are young, it seems an eternity from Christmas to Christmas. As we grow older, the years seem to shorten. “Where did the year go?” we ask.

The relativity of time is a natural product of age. When we are 10 years old, the year between Christmases makes up 1/10 of our time on the planet, even less when you consider that some of that time is spent in semi-conscious babyhood. At my age, 66, the year makes up a much tinier fraction, just 1/66 of my life.

Time is our most generous servant, but it is also our meanest master. Whoever we are, presidents or paupers, time will desert us.

Therefore, amidst the revelry, my thoughts turn to those for whom time has come to an end. I lost both my parents during the holiday season, and the world lost one of its most inspiring souls.

After 62 revolutions of our planet around the sun, old Cronus claimed Carl Sagan, noted astronomer and science writer, a dozen years ago on Dec. 20, 1996.

As he slowly died from bone-marrow cancer, Sagan gained some insight into the awesome, awful truth of time. He wrote, “We are like butterflies that flutter for a day and think it is forever.”

Sagan was one of the great science popularizers of our day. His writing was sometimes lyrically beautiful, a cosmic song that mirrored the grand harmonies of the universe.

He added at least one catch phrase to our language. The irony is that he never said it. His “billions and billions” originated in a loving parody of his style by late-night talk-show host Johnny Carson, who hosted him frequently as a guest on the show.

He wasn’t great shakes as an astronomer, however. He will not be remembered for any startling discoveries. His name will not be written in the book of scientific history.

In fact, Sagan was turned down the first time he was nominated to membership in the prestigious National Academy of Sciences. A few of its members blackballed him, saying that they felt uncomfortable being in the same organization as someone who had spent so much time on Johnny Carson’s show.

His field was planetary studies. He was particularly interested in the conditions under which life might form on other planets. It is a field, he admitted, without a subject matter. No such life has been discovered, and its study is purely speculative.

But he had what most of us lack — vision and the will to act on it. He saw the possibility for life at some time on Mars when most astronomers had given up on the idea. We search for that life to this very day.

He helped to create simple messages installed aboard NASA’s Pioneer and Voyager spacecraft. After visiting the outer planets, these interstellar travelers are now speeding through space with greetings to any civilizations they may chance to encounter.

Will they succeed in establishing communication? Probably not. They are, as Sagan liked to put it, our “message in a bottle,” hurtled into the void. They are, against all odds, a statement of our own optimism about the future of our own race.

His most lasting contribution to astronomy may be found in the contribution of others who come after him.

A whole generation of astronomers is now beginning to make its own contributions to astronomy. When they were young, many of them saw the Cosmos television series. Many of them were inspired to become astronomers, to find their unique places in the universe.

He helped us all to see that we are all part of the grand cosmic pattern that begins and ends with the birth and death of stars. He wrote, “The nitrogen in our DNA, the calcium in our teeth, the iron in our blood, the carbon in our apple pies were made in the interiors of collapsing stars. We are made of star stuff.”

Some doubters condemned such statements as irreligious, because they reduce the creation of human life to a sterile set of mechanistic equations.

Sagan saw the laws that govern the universe as a reflection of a greater spiritual majesty. “Science, he wrote,” is not only compatible with spirituality; it is a profound source of spirituality.”

We are, he said, on the verge of great discoveries. We stand, he said, “on the shore of a great cosmic ocean.” We must explore that ocean as surely as explorers sailed the great “ocean seas” of Earth. It’s in our blood. We can’t help ourselves.

In a time where budget cuts are decimating other sciences, astronomy and space science flourish. They have captured our national imagination because of Cosmos and the Johnny Carson show and because Carl Sagan knew so well how to find just the right words to infect others with his own sense of wonder.

Some of you may know that I am a writing teacher by trade. I admired him for his simple, yet profound, ability to put human life into a universal context.

With that lofty mission in mind, as the Voyager I spacecraft passed Saturn in 1980 and headed out into the void, Sagan asked NASA to turn its camera on the solar system and capture the sun and all its planets in what he called a “family portrait.”

He admitted frankly that the images would have no scientific value, and the final image of Earth is not very spectacular by NASA standards. It shows our planet as a “pale blue dot” caught in a ray of sunlight.

It’s nothing much to look at, except that it inspired Carl Sagan to create one of the greatest prose passages written in the 20th century. To this day, I ask my students to read that passage and imitate its style.

During this holiday season, I will read it again and again, ponder its insights, and study the order of its phrases and words in the vain hope that my own writing will capture a tiny fragment of the majesty of that single page of Sagan’s prose. Here is that passage:

Look again at that dot. That’s here. That’s home. That’s us. On it everyone you love, everyone you know, everyone you ever heard of, every human being who ever was, lived out their lives. The aggregate of our joy and suffering, thousands of confident religions, ideologies, and economic doctrines, every hunter and forager, every hero and coward, every creator and destroyer of civilization, every king and peasant, every young couple in love, every mother and father, hopeful child, inventor and explorer, every teacher of morals, every corrupt politician, every “superstar,” every “supreme leader,” every saint and sinner in the history of our species lived there — on a mote of dust suspended in a sunbeam.

The Earth is a very small stage in a vast cosmic arena. Think of the rivers of blood spilled by all those generals and emperors so that, in glory and triumph, they could become the momentary masters of a fraction of a dot. Think of the endless cruelties visited by the inhabitants of one corner of this pixel on the scarcely distinguishable inhabitants of some other corner, how frequent their misunderstandings, how eager they are to kill one another, how fervent their hatreds.

Our posturings, our imagined self-importance, the delusion that we have some privileged position in the Universe, are challenged by this point of pale light. Our planet is a lonely speck in the great enveloping cosmic dark. In our obscurity, in all this vastness, there is no hint that help will come from elsewhere to save us from ourselves.

The Earth is the only world known so far to harbor life. There is nowhere else, at least in the near future, to which our species could migrate. Visit, yes. Settle, not yet. Like it or not, for the moment the Earth is where we make our stand.

It has been said that astronomy is a humbling and character-building experience. There is perhaps no better demonstration of the folly of human conceits than this distant image of our tiny world. To me, it underscores our responsibility to deal more kindly with one another, and to preserve and cherish the pale blue dot, the only home we’ve ever known.

With Sagan’s death, astronomy is bereft of its most resonant voice. He is missed most of all by those of us who were inspired by the sweetness of his cosmic song. Yet during his brief time on the planet, he gave us the greatest holiday gift of all. We still sing his song.

Thus, during this holiday season, amidst the revelries of Christmas and New Year’s Eve, I will take a moment to think of the loved ones who have passed from my life. And on New Year’s Day, I hope you will join me in these ardently promised resolutions: “to deal more kindly with one another, and to preserve and cherish the pale blue dot, the only home we’ve ever known.”