Syzygy is an interesting word used in astronomy. It’s a great word for Scrabble, but my kids quit playing with me when I used it once. You might wonder what syzygy means. Let me explain.
This spring brings an unusual view of the solar system. If you get up before the Sun now through May, look to the east, and you will see four planets that shine very brightly. The planets from left to right are Jupiter, Venus, Mars, and Saturn. All of them will be bright enough to see with the naked eye. With binoculars or a small telescope, you will also see some of the moons of Jupiter and Saturn. Astronomers call an alignment of planets like this a syzygy.
We can see these planets in this rare alignment because they orbit the Sun in the same plane, called the ecliptic plane. This is not just some happy accident but is a critical factor in the survival of life on Earth. Objects coming into the solar system along the ecliptic will not collide with Earth because the planets that lie further out in the solar system will intercept them long before they can reach our planet.
We have actually seen Jupiter intercept a comet coming toward the Sun along the ecliptic. The fireball the impact produced was larger than Earth’s diameter. This solar system design is so complete that the gravitational fields of the outer planets overlap so that nothing from outside the solar system can get to the Earth. The only “planet” not in the ecliptic is Pluto, which is inclined to the ecliptic. For that reason, scientists say that Pluto is not a planet but a captured object.
The design of the solar system is far more complex than most of us understand. The more we travel in space, the more we see the effect of not having a designed protection system. As science deals with space travel, the wisdom and planning of God become apparent. Take a few minutes on a clear morning before the Sun comes up to go out and look and wonder at how “The heavens declare the glory of God” (Psalms 19:1). Now you know what syzygy means, and you can use it the next time you play Scrabble.
For most people, our Moon is just a light at night. The fact is that our essential moon is part of Earth’s fitness for life. Any change in the size, distance, or obit of the Moon would be catastrophic for life on Earth.
Having just one moon of significant size is a very unusual situation. Venus has no moons, and the two tiny moons of Mars are apparently captured asteroids. Jupiter, Saturn, and Uranus each have multiple moons, many of which are of significant size. However, a single large moon is unique to planet Earth.
So what does our essential Moon do for us? Because of its size, it has a significant gravitational pull on the Earth. That pull is strong enough to cause our planet to flex as the Moon orbits it. That creates a disturbance in geologic activity on Earth when the Moon is over an area of unstable rock.
The Moon’s pull on Earth’s waters is more significant. The Moon’s pull stirs the oceans much like a person might stir a large saucepan of soup. Our Moon causes many ocean currents and tides, even in large lakes. Ocean currents not only move nutrients around but transport heat as well. For example, the Gulf Stream is critical to marine life along the east coast of North America and controls temperatures along the entire coast.
The Moon’s gravitational pull is closely related to its mass. Therefore, a larger moon would cause massive flooding along the edges of continents. If it were smaller, the tides and currents would not be large enough to clean the estuaries or warm the landmasses, and many marine lifeforms would not survive.
If we had more than one moon, they would affect each other. There are rock tides causing moonquakes on the Moon due to the pull of Earth’s gravity. A second moon would amplify this effect, and if the two moons collided, the fragments would threaten life on Earth. Every total solar eclipse reminds us how precise the Moon’s size is. It can exactly cover our view of the Sun, allowing us to see and study the Sun’s corona.
Most of us overlook how our essential Moon’s size, mass, distance, and orbit shape seem to be carefully designed. Attributing that precision to blind chance requires faith as great as attributing life to chance. We would suggest that the Creator used his wisdom, described beautifully in Proverbs 8:1-5 and 22-32, to design an Earth/Moon system that allows life to exist and prosper on planet Earth.
An asteroid belt exists between Mars and Jupiter. Astronomers believe that this belt of material is either a planet that disintegrated or one that never formed because of the gravitational pushes and pulls of Jupiter and Mars. In 2007, NASA launched a probe called Dawn. In 2015, it arrived at one of the largest asteroids named Ceres. The Dawn probe revealed several strange white spots, especially in the Occator Crater. In August of 2020, astronomers presented several papers dealing with evidence that the white spots are ejections of salty water produced from holes punched into Ceres’ surface by space rocks.
Alan Stern of the Southwest Research Institute was involved in the NASA research on Ceres. He is quoted as saying that this discovery is “one of the most profound discoveries in planetary science in the space age.” The Occator Crater is 57 miles (92 km) wide. The material erupting through fractures looks very much like Utah’s Great Salt Lake.
Astronomers suggest that our solar system has large amounts of water stored in the moons of Jupiter and Saturn and Pluto’s surface. Trying to put together a model that explains the formation of wet moons and objects like Ceres is proving to be quite difficult. It appears that whatever the cause, our solar system has a unique water signature.
The abundance of water in the Milky Way Galaxy may turn out to be very important if humans venture into space and start establishing colonies on other worlds. Did God prepare a stepping stone for humans to move beyond Earth’s limitations by placing essential water in our solar system? Perhaps, but as we have said before, we face many other challenges as we venture away from our home planet.
One of the things that has entered the debate about life in space has been the presence of water. Astronomers have found methane, ethane, and other compounds in oceans on other planets and moons in our solar system. Unlike water, they are not polar molecules. The polar structure of water makes it an apparent necessity for life. Scientists have debated about whether water has existed or does now exist on Mars, our Moon, or one of the many moons of Jupiter and Saturn. Now there is evidence of massive amounts of water in our solar system.
We have posted before about NASA’s “Astronomy Picture of the Day” website (apod.nasa.gov). On January 15, 2021, the page showed this picture taken by the New Horizons spacecraft on July 14, 2015, as it flew by Pluto. The photograph shows areas of frozen nitrogen and carbon monoxide. It also shows massive amounts of water ice frozen into mountains reaching up to 11,000 feet (3,353 m), which is comparable to mountains on Earth.
There is more and more evidence that, at least in our solar system, water is quite common. Because of the temperatures in the outer planets, that water is in a frozen state. Liquid water has a very narrow range of temperatures, and that means the zone in which a planet can have liquid water is very small. Because of that, life on another planet is improbable, but the potential for humans establishing or supporting life elsewhere is relatively high.
Verse two of Genesis 1 tells us that the early Earth had water in the liquid state: “And the spirit of God moved upon the face of the waters.” Massive amounts of water apparently dominated the planet. Verse six tells us that there was “a firmament in the midst of the waters” that divided the waters. It isn’t until verse nine that dry land appears. The keyword in these verses is the word translated firmament in English. The Hebrew word used here is “raqia.” It is used nine times in Genesis 1 and eight times elsewhere in the Old Testament. Four of those eight are in the visions of Ezekiel 1:22-26.
The Bible’s economy of language leaves us to understand the “firmament” from its context. The most accurate understanding is what, in modern terms, we would call an “interface,” a zone of change. In many cases, that zone is the atmosphere, so in verse 20 of Genesis chapter one, we have birds flying in the firmament. Genesis 1:14-15 tells us that the Sun and the Moon became visible as the darkness (Genesis 1:2) of the cloud cover (Job 38:8-9) in the firmament cleared. Ezekiel saw his chariots in the firmament.
The discovery of mountains of frozen water elsewhere in the solar system indicates that the original cosmos had massive amounts of water, as Genesis 1:6 implies. It also tells us that when the Earth’s temperatures settled to between zero and 100 degrees Celsius, the water became seas covering the planet. This is one more evidence for the integrity of the Genesis account as it describes the creative design of God, simplified so that all humans can understand it.
The media often overlook how many things have to be “right” for life to exist on a planet. Planetary atmospheric pressure is one factor.
By “life,” we mean the standard textbook definition of organisms that can move, breathe, respond to outside stimuli, and reproduce. The problem is that many conditions make other terrestrial planets (planets with hard surfaces) unlikely to harbor life. Life is even less likely on Jovian planets that are primarily gaseous. You can postulate balloon-like living organisms in Jupiter or Saturn’s atmosphere, but radiation and electrical problems make that unlikely as well.
Planetary atmospheric pressure depends on the weight of the gases above a planet’s surface. The air pressure on Earth’s surface is 14.696 pounds per square inch a sea level. That pressure allows water to exist as a liquid, and it will enable various gases to dissolve in the water. We all know what happens when you shake a bottle of carbonated beverage and then quickly remove the cap. The sudden drop in pressure causes an explosion as the dissolved carbon dioxide escapes from the liquid. For organisms to absorb oxygen dissolved in water, which fish do, the atmospheric pressure must be high enough for the oxygen to dissolve. The atmospheric pressure on the surface of Mars is .01 of the pressure on Earth. That means water on Mars would contain no oxygen or dissolved gases.
There has been discussion about finding water on the Moon or Mercury, but those atmospheric pressures are considerably lower than those on Mars. That means water would not be in a liquid state. On the other end of the pressure spectrum is Venus, where atmospheric pressure 92 times greater than on Earth. At that pressure, toxic gases would be dissolved in any water that existed on the planet.
Planetary atmospheric pressure is just one more variable that must be carefully and precisely chosen when constructing an environment that will support and sustain life. The creation is far more complicated than most of us realize. As we learn more, we must stand in awe of the God who created our planet.
People give many different explanations of what the ”wise men” saw that led them to the Christ child. (See Matthew 2:1-12.) One of those explanations says there was a planetary alignment in the constellation Virgo (the Virgin). Since the magi may have been Zoroaster astrologers, they knew Christ had been born and followed “the star.” There is no connection between the star of Bethlehem and a planetary conjunction.
This December 21, at the winter solstice, there is a conjunction of Jupiter and Saturn. If you go outside about an hour after sunset and look to the southwest, you will see that the two planets are separated by less than a minute of arc, even though they are hundreds of millions of miles apart. If your eyesight is not very good, they may look like one very bright star.
This planetary conjunction is an exciting astronomical event, but it is not a good explanation of the star of Bethlehem. Whatever the magi saw, it could not have been a celestial star. Herod could have seen a celestial star for himself and would have had no reason to question its appearance as Matthew 2:3-10 describes. He could have had his people follow the star to find Christ and kill him.
Matthew 2:9 tells us that the star “went before them until it came to rest over the place where the young child was.” The closest star to planet Earth, outside of the Sun, is Proxima Centauri, and it is 4.2 light-years away. No stars move that way, and a planetary alignment is not a star.
The Bible does not present the star of Bethlehem as a natural object but as a miraculous act of God. Anytime the Bible says something is a miracle, it becomes a matter of faith, not science. How Jesus rose from the grave is not something we can scientifically explain. You either accept it, or you reject it, but all attempts to explain it naturally fail–and there have been many.
The star of Bethlehem was a miracle to show God’s acceptance of the Gentiles and to give Mary and Joseph the resources to move to Egypt and avoid Herod’s infanticide. The star of Bethlehem was not a natural event, but today’s planetary conjunction is. As we said yesterday, today’s event is not an omen and has no religious importance, but it is a rare, predictable astronomical event.
The ancient Greeks saw the five visible planets and called them “wandering stars” because they moved randomly across the sky instead of staying in fixed positions like the stars. The word “planet” comes from the Greek word for “wanderer.”
We have known for many centuries that the planets are not stars. They appear to wander because they orbit the Sun, just like our planet Earth. They orbit at different speeds, making them appear to wander in the sky. For astronomers to classify a celestial body as a planet, it must meet three requirements:
It must have enough mass for gravity to cause it to become spherical, unlike an asteroid.
It must not have enough mass to cause thermonuclear fusion, which would make it a star.
It must have cleared the area of debris known as planetesimals.
We have five planets that are visible without the aid of telescopes or even binoculars. Two of the visible planets are called inferior planets, not because of importance but because their orbit is inside Earth’s orbit. They are Mercury and Venus. The other three are known as the superior planets since they are beyond Earth’s orbit. They are Mars, Jupiter, and Saturn.
There is one essential thing the ancient Greeks did not understand about the solar system. They did not know that it is orderly. The Greeks saw a pantheon of gods controlling various aspects of the Earth and skies. Each of their gods had all of the bad traits of humans struggling with each other. It was the Judeo-Christian concept of one almighty and wise creator God who created an orderly system that led to the scientific understanding of the cosmos.
Astronomers today use technology to examine areas of the cosmos far removed from our solar system. The fact that they are finding the other systems are very much different from ours should tell us something. In fact, the more we study those other systems, the more we learn about our solar system design and why it is the way it is.
One interesting fact about other systems is that even though some planets are very large and obviously gaseous, they can exist very close to their stars. Astronomers in the past explained the fact that the inner planets of our own solar system are rocky and hard by saying that the Sun burned off the gases and left the rocky material. That may be partially true, but in 2002 astronomers discovered a planet they named OGLE-TR-56b. It is about the same mass as Jupiter but over 30 percent larger. It has to be a gaseous planet to have such a low density.
The surprising thing is that OGLE-TR-56b orbits its star at an average distance of only 2 million miles (3.2 million km). Our innermost planet Mercury is 36 million miles (58 million km) from the Sun. The outer atmosphere of this planet must be around 3000°F (1650° C). It is evident that gaseous planets can exist very close to their stars, so our old explanation of the inner planets in our solar system design is vastly oversimplified.
Most of the planets we see around other stars are very large, which is not surprising since it is easier to see a big planet than a small one. One extra-solar planet is 17 times as massive as Jupiter. The strange thing is that many of the giant planets are closer to the Sun than Venus. Old theories of planet formation suggested that due to the large gravity values of stars, it was impossible for planets to form close to the stars. We now know that is not true.
Science programs on television have delighted in proposing that the cosmos is full of planets and that every galaxy has literally millions of planets. The hope is that if you have enough planets, the chance of having another Earth is improved. We now know that many galactic systems do not have planets at all. The composition and age of galactic systems obviously have a major impact on whether planets can exist, but claims of billions of Earth-like planets in the cosmos are highly exaggerated.
The type of star also has an impact on whether planetary systems can form. Most stars in the cosmos are binary systems containing more than one star. A planet can orbit the stars at a great distance, but shifting gravity fields make planets unlikely if the stars are close together, as most are. How much metal there is in a star system affects planet formation. Metal content varies within galaxies as well as between stars. A part of space dominated by gases like hydrogen and helium are not as likely to produce planets as areas where there are large amounts of iron, manganese, cobalt, and the like. Solar system design requires the right kind of star.
Perhaps one of the most exciting lessons we have learned from other solar systems is that the shape of the orbits of planets in our solar system is very unusual. Most of them have very circular orbits meaning that their distance from the Sun does not vary a great deal. Venus has an orbit that is .007 with 0 being a perfect circle and 1 is a straight line. Pluto has the most elliptical orbit, but even Pluto is less than .3 on the 0-1 scale. Our solar system design is unusual.
Circular orbits like ours are very rare in other solar systems where .7 is a very common orbital value, and virtually all orbits exceed .3. If a planet swings far out from its star and then comes much closer, it should be obvious that temperature conditions are going to be extreme. Not only will such a planet have extreme conditions itself, but it will have a very negative effect on any planets that do have a circular orbit in the system. If Jupiter came closer to the Sun than Earth with each orbit, imagine the conditions on Earth as Jupiter went by us.
We now know that our gas giant planets (Jupiter, Saturn, Uranus, and Neptune) are essential to us because their gravitational fields sweep up any debris from outer space. Without those planets, comets and asteroids would pound Earth and life here would be difficult if not impossible. The fact that they are outside Earth’s orbit at a considerable distance and in a circular orbit allows us to exist in a stable condition for an extended time. The comets that do enter our system by avoiding the gas giants do not come in along the plane of the solar system called the ecliptic. Coming in from other directions, they have no chance of hitting Earth since they are not in the plane of Earth’s orbit around the Sun.
For all of my life, there have been articles, videos, and public presentations claiming that there must be life elsewhere in the universe. Now that we know there are thousands of planets in the creation, we see attempts to maintain that with so many planets there must be life somewhere. Scientists are even speculating alien life without water.
We need to remember that the Bible doesn’t say that this is the only planet where God created life, so this is not a biblical issue. The latest attempts to expand the window of what life is has rejuvenated the need to show the design built into the development of life. Life on Earth is based on carbon, hydrogen, oxygen, and nitrogen. The National Science Foundation has just funded a three-year program at Saint Louis University to explore what building blocks might be used to make a different kind of life. The chemicals they are considering are hexane, ethers, and chloroform. There is particular interest in whether these materials can form membranes that could be considered life.
The first problem is the definition of life. Life has traditionally been defined as “that which can move, breathe, respond to outside stimuli and reproduce.” An extraordinary chemistry is necessary to meet all of these criteria. Water is the basic substance of life on Earth. The water molecule is polar, meaning that one end of the molecule is negative and the other end is positive. Oxygen is the negative end. Oxygen’s bonding orbitals allow the attachment of two hydrogen atoms making that end positive. This polarity allows water to dissolve other molecules. Salt, for example, is made up of sodium which is positive and chlorine which is negative. When you put salt in water, the sodium is attracted to the oxygen end of the water molecule, and the chlorine is attracted to the hydrogen end of the molecule because unlike charges attract each other. This pulls the salt molecule apart and allows the salt to dissolve. Alien life without water seems impossible.
Hydrocarbons like methane have four hydrogen atoms attached to the carbon atom symmetrically. That makes the molecule non-polar and unable to dissolve salt. Numerous experiments are underway to circumvent this problem including the use of vinyl cyanide (also called acrylonitrile) which has been found in the atmosphere of Saturn’s moonTitan. Coming up with a formula for alien life without water will be difficult. How a substitute for oxidation would work has not even been publicized, so respiration would be an equally great challenge.
When it comes to moons, it seems that Earth got cheated. We have only one moon while Mars has two. Neptune has fourteen moons. Uranus has twenty-seven. Saturn not only has rings, but it also has sixty-two moons. (Update- We now know that Saturn has 82 moons! Lucky Jupiter has sixty-seven! (Update- It’s now 79!) To add to the embarrassment, puny little Pluto, which is no longer considered a planet, has five times as many moons as Earth has! The only bragging point we have is that we can say we have more moons than Mercury and Venus. (They have none.) So how many moons are enough?
Actually, one works very nicely. Our single moon is critical to the existence of life on Earth. It’s because of the moon that Earth has a stable tilt on its axis of 23.5 degrees. That tilt prevents temperature extremes on this planet. With no inclination, the area of the Equator would be extremely hot and the poles extremely cold and dark all year. With a greater tilt, seasonal weather changes would be extreme all over the planet. Because of the angle of the inclination, we have proper seasons, and the air gets mixed to temper the weather extremes.
Our moon has the right mass at the right distance to keep Earth’s tilt stable. The moon plays several crucial roles in making our planet a great place to live, but stabilizing the tilt is one that’s extremely important. So how many moons are enough? I would say that one moon of the right size and at the right distance is just right.