Astronomer Daniel Goldin philosophized during Hunt for Alien Worlds, a program in the NOVA series aired on many U.S. Public Broadcasting Service stations: "We all search for meaning to life, and if-if we would even have a discovery that there is a habitable planet, let alone life on it-I think it would uplift the human spirit."

The desire to know the meaning of life is a worthy aspiration, and to explore whether life exists somewhere else in the universe is a natural consequence of that desire. Do planets circle distant stars somewhere in another galaxy? Scientists want to know.

The Hale-Bopp comet earlier this year left behind more than a spectacular prismatic spray of cosmic moisture. This celestial chunk of ice stirred imaginations to wonder about other planets-and other life-somewhere in the remote regions of the universe.

Such speculation is aided by today's telescopes. They are so powerful that some believe that the discovery of life on other planets is within reach. It's this kind of technological advantage that raises such expectations.

Historical perspective

The greatest challenge astronomers face in their search for other planets is that they can't see them. The only planets we can directly observe are those we can view in the night sky, such as Mars and Venus, some of those that make up our solar system. Although some nearby planets are visible to the naked eye, those in the farthest orbits of our sun's system took hundreds of years to discover. Uranus wasn't discovered until 1781, Neptune in 1843 and Pluto in 1930 (captured in a telescopic photograph). It wasn't until 1990, with the help of the Hubble Space Telescope, that Pluto's moon was captured in a photograph.

Scientists assume that other solar systems with planets like ours exist and harbor intelligent life.

According to George Gatewood of the Allegheny Observatory in Pittsburgh, Pennsylvania, actual observation of a planet outside our solar system is virtually impossible. Would that scientists could simply point their telescopes at a star and observe planets encircling it. "The difficulty is that planets do not give out much light," Dr. Gatewood says. "It's entirely reflected light."

To highlight the difficulty of locating planets in other solar systems, Dr. Gatewood compared the task to spotting a firefly fluttering at the edge of a huge searchlight. If the searchlight weren't there, you might be able to see the firefly's tiny glimmer, but in the searchlight's overpowering illumination the firefly is imperceptible. This is a good example of what astronomers face in their search for planets beyond our solar system.

However, technological advancements can circumvent even this challenge and can lead to the discovery of planets.

Wobbly stars

All planets, stars, moons and other heavenly bodies are affected by the gravitational force of their neighbors in space. With this in mind astronomers have deduced the existence of some planets by observing their gravitational effect on nearby "wobbling" stars. In recent years state-of-the-art optics and data collection have dramatically improved astronomers' chances of finding otherwise imperceptible planets.

Their technique is called astrometry. It is a process similar to collecting frames for a movie. On a given night, astronomers photograph a section of the sky and measure the relative positions of celestial bodies. This process is repeated on later nights. They then compare the frames as though they were in a movie, noting whether the stars' motion is in a straight line or whether some show a slightly wavy pattern. Even if a wavy pattern is discernible, it is still difficult to determine whether the gravitational pull of a planetary body is the cause.

Even a planet the size of the giant Jupiter-1,000 times the earth's size-would have an almost indiscernible effect on a star within a solar system. Another problem is that the earth's swirling atmosphere causes starlight to twinkle and in turn obscures the potential apparent wobbles caused by any orbiting planets.

Astronomers have made some headway on this problem using the Hubble telescope. Put into orbit high above earth's atmosphere by the space shuttle Discovery on April 25, 1990, this telescope "is able to peer far out in space and back in time, producing imagery of unprecedented clarity, of galaxies, star systems, and some of the universe's more intriguing objects: quasars, pulsars, and exploding galaxies." The telescope "can distinguish fine details- in planetary atmospheres or nearby star fields-with ten times the clarity of the best ground observatories. When pointed at Jupiter, for example, the telescope provides images comparable to those from Voyager flybys" (Otto Johnson, editor, Information Please Almanac, Houghton Mifflin Company, Boston and New York, 1997, p. 349).

Unfortunately for planet hunters, Hubble's amazing abilities mean it is in high demand. Other tasks of a higher priority can and do get more attention and time; the search for planets gets relatively little opportunity.

Astronomers at the Lick observatory near San Francisco are perfecting another technique less vulnerable to atmospheric distortions and variations: measuring the color variations of a star caused by motion induced by the gravitational pull of nearby planets.

A star's light contains more than the spectrum of rainbow colors. Atoms and molecules in a star's atmosphere absorb part of its light before it passes into space. By recording a star's "absorption lines," the astronomer can create a type of fingerprint of the light that can be precisely fixed to one location. If the star is being tugged by an unseen planet, the image will shift from side to side. Use of this technique is called spectroscopy.

Is our planet unique?

For millennia man has searched for answers to the questions about life: Why are we here? Where are we going? Are there higher forms of life? Is there a God?

The theory of evolution is a hybrid hypothesis, an attempt to explain a vast and magnificent universe that operates according to defined laws of physics, but one with no guiding force other than random, mindless chance. Further, it offers no explanation for how the universe came to be-only how some think life came to exist from nothing more than a soup of chemicals.

Such theories appear to have been invented to explain the phenomenon of created things without a Creator. Nearly all scientists admit that no one theory can explain the existence of an orderly universe, galaxy and solar system, nor the earth's incredible ecosystems.

Is our planet unique in all the universe? In spite of statements and hypotheses from astronomers, there are no scientific facts, no hard data, that conclusively point to another habitable, earthlike planet with any life-forms on it, simple or complex. Hypothesis is not theory, and theory is not observable fact. The distance between hypothesis and fact could be measured in light-years.

The Supreme Being revealed in the Bible claims to have created this planet from the invisible (Hebrews 11:3). In Genesis 1:1 we read, "In the beginning God created the heavens and the earth." The Bible ascribes the creation of everything to the living God, not to randomness.

Genesis describes a time "in the beginning" when nothing physical existed, and God created the material realm-the heavens (plural) and the earth. Obviously the universe with its multiple galaxies is much greater in size than the earth. The earth is but one tiny planet, while astronomers estimate some several hundred billion stars in the observable universe.

So what would make this planet unique, as God implies in Genesis 1:1?

A divine plan for mankind

According to the Scriptures, God has a plan for people. This plan was formulated before the universe was created-an unimaginable era "before time began" (2 Timothy 1:9; Titus 1:2; emphasis added). This plan includes changing humans from physical to spiritual, mortal to immortal (1 Corinthians 15:49-54).

Careful scrutiny of the Scriptures shows us that man is destined to become part of the family of God (1 John 3:1-3; Hebrews 2:10). "I will be a Father to you, and you shall be My sons and daughters," He promises (2 Corinthians 6:18). The earth has been set apart as a one-of-a-kind planet-the training ground for God's future children!

There might well be planets in distant galaxies orbiting distant stars. But so far there is no real evidence that life-forms exist on other planets.

God shows there is meaning to life, and it can be found in the pages of your Bible. In spite of the failure to find life on other planets, we are not alone in the universe. God and Christ and millions of angels exist in the spirit realm, as of yet unknown by most of humanity.

Rather than looking to astronomers and other scientists to discover the meaning of life, why not seek out the one Being who can answer our most difficult questions and show the way to a fulfilling life now and forever on this planet? GN