Planet-Moon Size Ratio

Planet-Moon Size Ratio - Earth and Moon

What is the optimum size for a planet to form a just-right moon? According to a new study, the short answer to that question is, “Just about the size of planet Earth.” Is that another coincidence or a matter of design? First, let’s consider the planet-moon size ratio.

The radius of the Moon is a little more than one-fourth of Earth’s radius. That four-to-one ratio is unlike any other planet-moon size ratio in our solar system. The solar system’s largest moon is Ganymede which orbits Jupiter. It is one-third larger than our Moon, but Jupiter is more than 11 times the diameter of Earth. The essential factor is that our Moon is larger in relation to the size of the planet it orbits than any other moon in the solar system.

Scientists believe that our Moon was formed when a planet the size of Mars collided with the early Earth. The heat caused by the collision vaporized the material, which eventually congealed to form the Moon and planet Earth. (See Genesis 1:1-2.) The angle of that collision was precisely fine-tuned to result in a planet and moon with the exact size ratio for the Moon to control Earth’s tilt, rotation speed, and ocean tides, as well as perfectly covering the Sun during a total solar eclipse.

To suggest that the creation of a planet perfect for advanced life could have been an accident requires that you have a lot of faith in chance. But a new study by researchers from the University of Rochester in New York adds even more evidence for design. They found that a planet more than 1.3 to 1.6 times Earth’s size could not form a moon that would have the “life-enabling effects” that our Moon has.

Computer modeling shows that if larger planets collided, the energy of the impact would vaporize the material, but a stabilizing moon could not form. The vaporized material would cause drag on the planet, slowing it down so much that gravity would cause any material that congealed to crash into the planet. Not only is the planet-moon size ratio essential, but so also is the size of the colliding bodies.

Numerous factors beyond the planet-moon size ratio must be just right for a functional, life-supporting planet to form. Our planet meets every one of those requirements, and so far, astronomers have not found any other planet that does. The Bible does not tell us whether God chose to create life on another suitable planet anywhere in the universe. However, scientists will never stop looking for it. In the meantime, they keep finding factors that show evidence of intelligent design everywhere in the universe.

— Roland Earnst © 2022

References: and Nature Communications

Our Essential Moon and Life on Earth

Our Essential Moon and Life on Earth

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.

— John N. Clayton © 2021

Reference: Smithsonian magazine, December 2021, page 88.

Space Is Not Orderly and Simple

Space Is Not Orderly and Simple

Our Milky Way galaxy is somewhat orderly, with the stars orbiting what appears to be a large mass at the center – probably a black hole. Simulations of galaxies shown on science programs present a consistent whirlpool of material, all spinning in the same direction and obeying the physical laws we teach in a high school physics class. But space is not orderly and simple.

Simple explanations don’t work with galaxies like M64, sometimes called “The Evil Eye Galaxy” or “The Black Eye Galaxy.” In that galaxy, stars and gas close to the core orbit in one direction, but those further out rotate around the core in the opposite direction. Astronomers believe that this behavior indicates two galaxies collided, producing the confusion, but why the systems are in the same plane doesn’t match that explanation well.

There are cases in our solar system where objects revolve in different directions, including the moons of Mars and some other planets. Uranus is tilted on its side, spinning perpendicular to the ecliptic. Space is not orderly and simple or as benign as science fiction might like to portray it. Each time science makes a discovery showing that space is not orderly and simple, we have to wonder at God’s creative nature. Did He put some of these things together to challenge our creative thinking?

The most exciting aspect of all this is the unique stability and beauty of our planet. On March 27, 2021, NASA released a report stating that new telescope observations show there is no chance of something in space colliding with Earth that would threaten our existence for at least the next 100 years. We should thank God for His marvelous creation and for the fact that He designed our planet for the long haul. Now, all we need to do is to take better care of it.

— John N. Clayton © 2021

For more on M64 see the “Astronomy Picture of the Day” for March 29, 2021.