Have you noticed how the news has been running on two different tracks lately? The truth is, it probably always does, but every now and then the split suddenly seems more striking. On the one hand, there are the day-to-day ups and downs of human existence, everything from the weather to prognostications of war. That’s the short-term track. On the other hand, there is the super-long-term track: the one that concerns itself with the history of the cosmos, where we came from and where we are going, the general alpha and omega of things. This month, side by side with Iraq and North Korea and the economy and Hideki Matsui, there has been quite a flurry of these grander stories, rendering them all curiously unimportant.

In a way, the Columbia disaster foreshadowed it. Not in itself, because what is the space shuttle, after all, but a high-tech workhorse toiling to and fro on everyday, low-level missions? Columbia never flew farther than the cosmos’s doorstep. Yet when it broke up in flight Feb. 1 it prompted an outbreak of soul-searching, not just on the part of NASA officials in the United States, but around the world.

In a moment, humanity’s entire mission in space came under fire: Where are we headed? What are we — the space nations — actually doing puttering back and forth to the International Space Station? Whatever it is, is it worth it? What about our plans and hopes for Mars? These are issues that need to be addressed soon, since they bear on the immediate future of both the space-shuttle program and the ISS. Yet implicit behind all the short-term uncertainty is the single long-term question: Where does our future lie?

The week after Columbia, there was another sharp reminder of what came before us — and, again implicitly, how brief humanity’s moment in the sun has been. Russian and Japanese scientists announced that they had recovered live cells from a frozen, 10,000-year-old Ice Age woolly mammoth that could theoretically provide DNA adequate for cloning. The elated scientists, led by Dr. Kazufumi Goto, formerly of Kagoshima University, say that in the meantime they plan to create a near-100 percent mammoth by artificially inseminating an elephant. This creature and any companions would, it is hoped, be free to roam the Ice Age-like landscape of Russia’s remote Kamchatka Peninsula.

As if that weren’t enough to fire the imagination, the woolly mammoth story was overtaken a few days later by an announcement that puts even the Ice Age in the shade. A pair of American scientists, an astrophysicist and a paleontologist, published a new doomsday scenario, “The Life and Death of Planet Earth,” which predicts with relentless severity the passage our planet will take toward death — and when.

If you think of Earth’s life span as a 12-hour clock, running from midnight to noon, they write, we are already at 4 a.m. By 5 a.m., just half a billion years from now, the blink of time hospitable to complex life forms — plants, animals and human beings — will be over. After that, ice again, and then fire, as Earth is consumed by the sun. Fantasy? The sobering reality is that to the extent that scientists dispute this scenario, it is only in the details.

Finally, last week also saw NASA’s publication of a “photograph” of what they call the infant universe, the result of measurements of faint emanations still visible from the Big Bang. To be frank, NASA seemed to us to be able to read a remarkable amount into this one blobby, swirly picture: not just what the universe looked like 380,000 years after the Big Bang, but when the Big Bang occurred (13.7 billion years ago), when the stars ignited (200 million years later) and when and how the universe will someday end. Pretty good for a single shot. But the point, as with the other stories, isn’t the science itself, which is subject to debate and refinement, but the enormously elongated time frame it presupposes, which is not.

Nowhere is the contrast in perspective so arresting as in the headlines. Last Monday, for example, readers were asked to contemplate, more or less together, U.S. President George W. Bush saying that “the U.N. faces a ‘moment of truth’ about Iraq” and scientists declaring that “Earth’s hot birth foretells its death” — another order of truth entirely. “The United Nations gets to decide shortly whether it is going to be relevant,” Mr. Bush is quoted as saying.

Meanwhile, we are trying to absorb that doomsday story, which casts doubt on the “relevance” of human existence itself. If the entire span of life on Earth is just a blip in the immense, inexorable timetable of the universe, then the U.N. has nothing to worry about. None of us does. In the grimmest possible way, isn’t the two-track phenomenon comforting?

In a time of both misinformation and too much information, quality journalism is more crucial than ever.
By subscribing, you can help us get the story right.