One of the interesting developments of the past twenty years has been the study of planets orbiting stars other than our Sun. So far, scientists have discovered more than 4,000 exoplanets. Those who believe the formation of Earth and its ecosystem is a product of blind mechanical chance seize upon this fact to affirm that God had nothing to do with the creation. They argue that given enough time and enough planets, life was bound to happen somewhere eventually. Do exoplanets disprove God?
One obvious difficulty with this claim is that the real issue of creation is how time, space, and matter/energy came into existence in the first place. How it got into a form that would sustain life is a matter of whether the creation was designed and planned by an intelligence, or whether it was a product of chance. Astronomy magazine, in its January 2020 issue, carries an article about the summer 2019 discovery of the first planet that exists in the habitable zone of its star. The media at that time made wild claims about the probable existence of life on that planet. Known as K2-18b, the planet orbits a red dwarf star which is about one third the mass of our Sun. What that means is that water could exist on the planet as a liquid.
So could life exist on K2-18b? This discovery highlights the incredible complexity of planet Earth. K2-18b is roughly twice the diameter of Earth and eight times as massive. The mass of the planet means that gravity there would be much higher than Earth’s gravity. That would result in a much deeper and denser atmosphere with pressures and temperatures thousands of times higher than we experience on Earth. Also, red dwarf stars emit powerful flares, and the orbit of K2-18b is twice as close to its star as Mercury is to the Sun. There is no way that life could survive the conditions on this planet, even if liquid water were present.
Remember that K2-18b is the first planet discovered that is located in a so-called habitable zone. The study of exoplanets has shown that the creation of planet Earth is a highly unique and special event. Do exoplanets disprove God? As we have said before, God can create life anywhere He wants to. But as more and more data becomes available on what exists throughout the cosmos, support for God as the creator and sustainer of life on this planet grows.
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.
The Sun’s corona visible during the 2017 total eclipse.
Our Sun is a special star. In the past, scientists thought that it was just an average star. However, new studies in recent years have shown many ways that our Sun is unique.
A recent study by researchers at the Flatiron Institute Center for Computational Astrophysics under the leadership of astronomer Megan Bedell shows one more way that our star is unique. The study involved examining 79 “solar twins” of the Sun. These are other nearby stars that have nearly the same temperature and mass as the Sun. Using the HARPS telescope in Chile, they measured the spectra of each of the stars. A star’s spectrum of radiation indicates what elements the stars contain and the relative abundance of those elements.
The researchers measured the abundance of 30 different elements to a precision of two percent, which is higher than others had achieved. The ratios of elements such as carbon to oxygen and magnesium to silicon were nearly identical in the stars they studied, except for the ratios in our Sun. Our star has a lesser amount of metals and elements that make up rocks. Those elements are the ones which planets are made of, so we can probably assume that those elements were removed from the Sun to make Earth and the other rocky planets.
The stars which came closest to matching the Sun’s chemical composition were only a small portion of the total stars studied. They are also missing some of the materials that could build planets like Earth. However, in the search for exoplanets, astronomers so far have not found any planets orbiting those stars that are most similar to our Sun.
We commented in a previous post about extra-solar planets (planets orbiting other stars), and whether those planets could have life on them. The media seem to convey the idea that there are hundreds of “earths” all containing life-forms similar to us. They suggest that if there are many Earth-like planets with life on them, then that indicates that Earth and the life on it came about by chance processes. In February, NASA called a special news conference to announce that they had found a star they call TRAPPIST-1 which had seven Earth-sized planets orbiting it in the “Goldilocks Zone.” The Goldilocks Zone is the area where water could exist in the liquid state. Many media sources were quick to announce that NASA had found seven planets that were “Earth twins” and almost surely would be inhabited.
Let us emphasize again that finding life in space is not an issue of whether God exists. If scientists find life in space, it will have been created by God and will have a purpose in existing. This particular find, however, is just another example of how quickly and irresponsibly the media will jump to promote an agenda that will sell. As more data has become available, it is becoming increasingly obvious that this seven-planet system is not an ideal place for life. In fact, any life form that happened to be there would be destroyed by the properties of the system.
TRAPPIST-1, the star that serves as the “sun,” is a very cool dwarf star. That means it gives off a very limited spectrum of light. The critical wavelengths required for photosynthesis and chemosynthesis are simply not present. The masses of these planets range from .4 to 1.4 times the mass of Earth. That means the smaller planets will almost surely not have an atmosphere since they are smaller than Mars. The length of time for the planets to orbit their star varies from 1.5 days to 20 days. That makes a very short year. They are all less than 6 million miles from their parent star. That means all activity on the star would likely be lethal to life-forms on the planets. For a comparison, Mercury, the planet closest to our Sun is separated from it by 36.8 million miles. Earth is 93 million miles from the Sun.
On February 23, 1987, a historic explosion was witnessed by astronomers on Earth. A massive star known as Sanduleak -60 degrees 202 exploded. What was previously classified as a supergiant star became a supernova. For the first time since A.D.1054, there was a supernova close enough to the Earth for scientists to observe first-hand what was happening.
Students in high school physics and earth science classes study a diagram known as the Hertzsprung-Russell diagram. It is simply a scattergram of the temperature of stars plotted against their luminosity. Stars begin as very hot blue giant stars. As they cool, they turn white-hot, then red, then brown. Then they may become a cinder. In the case of larger stars, the internal processes change, and they become giant stars which in some cases explode. Because these processes require a very long time, we don’t live long enough to see a single star go through all of these phases. But we can see stars in all of these stages. Seeing a star explode is a very rare event (about once a century), and Sanduleak -60 degrees 202 was thus a fantastic opportunity to see in detail what happens when a star explodes.
There is much to learn from Supernova 1987A. Exploding stars seed space with the heavier elements. We are learning how the elements that make up our world were formed. For those of us who believe God is the engineer of all of this, we can see how God made iron, copper, gold and the materials of the Earth’s crust. The incredible energy and power of the process testify to God’s power and creative wisdom. As we compare this supernova with the one that happened in A.D. 1054, which produced what is now called the Crab Nebula, we see it is different in many ways. In 1 Corinthians 15:41 the Bible tells us that “one star differs from another” and we now know that is true even of exploding stars. This supernova also gives us another tool to measure the size and age of the universe. We have several methods of measuring how far away this supernova is, but they all give us the same answer. The explosion took place 160,000 light years away from us, or 160,000 years ago. We are safe from the incredible radiation because of the huge distance.