Life in the Universe

Current scientific evidence indicates that the Universe is 13.7 billion years old and that the galaxies formed 12 billion years ago.  Yet, our home star, the sun, is less than 5 billion years old, the Earth  formed just 4.6 billion years ago, unicellular life did not evolve on our planet until 3.6 billion years ago and we humans did not appear until 130,000 years ago.  Countless suns, their solar systems and the life that inhabited their planets likely evolved and disappeared long before our own sun and planet came into existence.

Among the 100 billion galaxies and trillions of stars that stretch across the ever-expanding Universe, there are surely millions of other planets that sustain life which, in many if not most cases, has progressed farther along the evolutionary tree than has life here on Earth.  In other words, it is almost a certainty that many human-like civilizations inhabit this Universe, most of which are more advanced than our own.

It is understandable that religious persons might find these rational facts too threatening to contemplate but it is disconcerting to hear scientists and scientific journalists question whether life exists elsewhere in the Universe.  Sitting here on our smallish planet that circles a modest-sized star on an outer band of a massive galaxy, it is absurd to suggest that we might be the only intelligent beings that inhabit the billions of galaxies.  The Universe surely teems with life and it is only our irrational self-importance that keeps us from embracing that fact.

Racing Past the Solstice

Last evening, the Northern Hemisphere crossed the summer solstice, its annual maximum tilt toward the sun.  Over the next six months, the sun will gradually retreat to the south and, in concert, our hours of sunlight will steadily diminish until we reach the winter solstice, on or about December 20.

It will take several weeks before we notice much change in the sunlight and several months before the longer nights take a toll on the summer heat.  Of course, the rate of change will be far more dramatic in the Arctic, sending shorebirds south by August and waterfowl in their wake.

Those of us who are not fond of hot, humid weather look forward to the cool, crisp weather of autumn and would like to accelerate the sun's retreat.  But it is the Earth's journey that governs our seasons, revolving around our home star on a tilted axis, steadily changing the angle of solar radiation that we receive.  Since we are already moving at 66,000 miles per hour to cover the 300 million miles between summer and winter solstices, a bit of patience seems to be in order.

Moon over Venus

Last evening, a crescent moon gleamed in the southwest sky, its southern point tipped toward the horizon. Below the moon was Venus, its position suggesting a bright ornament hanging from and tilting its larger companion. This, of course, was an illusion, a product of my vantage point and the distance of those heavenly bodies from Earth. In fact, Venus has a diameter of 7521 miles, more than three times that of the moon; however, at its closest approach, Venus is 25 million miles from Earth, more than 1000 times the distance from Earth to the moon.

Such astronomical illusions have confused humans since our earliest days, leading us to see relationships among the stars and planets that don't actually exist. Indeed, many of the named constellations consist of stars that are farther from one another than each is from the Earth; their grouping in the night sky is merely a consequence of our own location in space. For astrologists or other pseudo-scientists to make predictions based upon the relative positions of certain planets and constellations is thus pure folly.

Of course, man's history of misinterpreting nature extends well beyond the night sky. Before the scientific era, assumptions were made that, today, seem to be remarkably naive, if not comical. Then again, even our modern understanding of nature's complexity, from atoms to ecosystems, continues to evolve and, centuries from now, our perspective will have changed dramatically. Science is, after all, a process and a healthy degree of skepticism is essential to its advance.

Darker Days, Brighter Nights

In the American Midwest, winter days are darker and, of course, shorter; sunrise begins later and sunset occurs much too soon. While sunny days come along, most are cloudy and the low sun angle provides little heat. It is, indeed, a gray and daunting season.

On the other hand, winter nights are often ablaze with stars. The dry, frigid air, free of summer haze, provides an unfiltered view of the heavens, a dazzling display of light arriving from the distant past. Though our own sun has retreated to the south, thousands glow overhead, lending perspective to our lives here on Earth.

The depth of our winter darkness is less than three weeks away but solar warming will take much longer to recover. Until then, we can gaze at distant suns, knowing that they are bringing summer heat to countless populations across our vast Universe.

Return of the Hunter

For the past week, Orion the Hunter and his faithful dog Sirius have returned to the southern sky during the predawn hours. Their appearance heralds the culling season, when a deepening chill engulfs the landscape and predators gain the advantage. By mid winter, Orion and his companion will dominate the long, frigid nights and our survival skills will be tested.

For now, Orion shines from the mild morning darkness, lying in wait above the colorful fields and woodlands. We still have at least six weeks of glorious weather before winter takes control; the painted forest has yet to peak, waterfowl are just beginning to fill our wetlands and a new generation of wildlife has yet to experience the frost of autumn.

But the tide has turned and summer is slowly retreating to the south. The days are noticeably shorter, the evening chill comes earlier and hunters sense that their season is at hand. Nature's cycle is nearly complete.

Nature's Nightlight

Torn from Planet Earth by a violent collision, more that 4 billion years ago, the moon's cratered face attests to its traumatic childhood. Yet, in more recent times, our lone satellite has become a cherished feature of the night sky, a beautiful and tranquil companion that has long inspired mankind.

Unlike the sun, that hurls intense light, stifling heat and ionic waves in our direction, the moon is a calm, reflective body, changing its face but not its mood throughout its monthly cycle. Nevertheless, it has played an important role in the evolution of Earth's ecosystems, stabilizing the axis of our planet and producing the tides that, 400 million years ago, allowed life to colonize the land, and, today, provide vital nourishment to coastal habitats.

On the last two mornings, I watched as the full moon dropped below the western horizon. Unaccompanied by the colorful skies and changing light of a sunset, the moon departs with little fanfare but we will look for her when the darkness returns. Afterall, throughout most of human history, the moon was our nightlight, a source of reassurance amidst the turmoil and uncertaintly of our fragile existence.

A Miocene Supernova

The Miocene Epoch of the Tertiary Period stretched from 22 million years ago (MYA) to 5 MYA. During that time, ancestral apes and early hominids appeared in Africa, Kure Island (now an atoll) and Midway Island developed above the Hawaiian hotspot, the Columbia Plateau formed from massive basalt flows, Iceland emerged from the sea, the Intermountain West was uplifted another 5000 feet, the Gulf of Aden began to open and the East African Rift started to form. In addition to ancestral apes and hominids, the first true elephants, giraffes, okapis, hippos and North American pronghorns made their appearance.

Two weeks ago, on August 24, astronomers from the University of California observed the sudden appearance of a supernova in the Pinwheel Galaxy, 21 million light years from Earth; in other words, they observed the explosion of a star that occured during the early Miocene. Brightening by the day, the display is expected to peak between September 9 and September 12, when it should be visible with powerful binoculars or a small telescope. Located in the Ursa Major (Big Dipper) constellation, the supernova will appear as a bluish-white star just above and slightly left of the last two stars in the Big Dipper's handle.

When we look at the night sky, we are looking back in time. The light from stars, traveling at 186,000 miles per second, takes years to reach Earth, even from our closest neighbors; Sirius, for example, the brightest star in the sky, is 8.7 light years away (if it exploded eight years ago, we will not know until next May). While the Miocene supernova in the Pinwheel Galaxy exploded 21 million light years from Earth, it was a nearby event relative to the vast expanse of the Universe.

Ocean Sunsets

Sunset, whether unfolding behind a range of mountains, amidst the painted skies of the Great Plains or beyond the jagged silhouette of a modern city, is always a beautiful and stirring event. Ocean sunsets, however, seem to produce more emotional impact, as our glowing, orange star drops below the edge of the Earth.

Often witnessed by crowds of humans, whether on beaches, on a ship or on shoreline balconies, ocean sunsets are usually a collective experience, igniting a sense of wonder but dredging up a deep-seated fear, buried in the soul of man. Long before we came to understand the motion of heavenly bodies and the astronomical cause for sunsets, the gathering darkness, frought with a host of natural dangers, was surely a source of concern; whether the sun would return, bringing its life-sustaining heat and light, was not taken for granted.

Even today, as the sun drops behind the sharp line of the sea, this fear, however weak, wells up from our genetic past. While we might not acknowledge its presence, it surely plays a role in our emotional response to sunsets. Natural beauty, after all, comes with a price and our personal capacity to ward off the darkness is but a transient gift.

Night of the Geminids

While not as famous as the Perseids of August or the Leonids of November, the Geminid meteors of December offer the most reliable display of the year. Produced by debris from the 3200 Phaethon asteroid, discovered in 1983, the Geminid meteors were first observed by a British astronomer in 1862, making them the youngest of the annual meteor showers; indeed, most of the other major displays, produced by debris from comets, have been documented for thousands of years (and have likely occurred much longer than that).

The Geminid debris field is the largest that Earth encounters in its annual journey around the sun. Up to 160 meteors may be seen in the course of an hour, seeming to radiate from the Gemini constellation; since they are relatively slow moving (compared to meteors in other displays) and since they tend to leave a vapor trail, the Geminids are also the easiest to observe.

Occurring from December 6 to December 19, the Geminid meteor show peaks on the nights of the 13th and 14th; as with all meteor displays, they are best observed on clear, moonless nights, away from the glow of city lights. Fortunately, astronomers project that the Geminid display will intensify over the coming years as Earth's orbit more directly intersects the path of the parent asteroid.

Cheshire Moon

Stepping onto the deck last evening, I caught sight of the crescent moon, turned on its back in the western sky. Catching the orange glow of the setting sun and looming just above a branch of our neighbor's tree, it evoked the grin of the Cheshire Cat, Alice's friend and nemesis.

Both enamored with and frightened by the winter night, humans, like Alice in Wonderland, have long confronted its mysteries and threats. Natives of the Tropics, we are poorly equipped to survive the harsh conditions of winter and, devoid of night vision, we remain at the mercy of creatures that patrol its darkness. And the night sky, with its fabulous cast of glowing objects, has long inspired and threatened man, prompting us to imagine figures and omens in its pattern of moving lights.

As the Cheshire Moon dropped toward the horizon, I turned my attention to bright Jupiter, high in the southern sky, and to the other constellations that adorn our winter nights. Despite our advanced scientific knowledge, we have only begun to understand the worlds beyond our own. One day, if we do not destroy our own civilization first, we will step through the looking glass to explore the rest of our Universe.