The Size of Our Galaxy

on July 29, 2009

God made the universe unimaginably large. The universe contains objects of incredible size and mass at distances which the human mind cannot fully grasp.

The heavens declare the glory of God; the skies proclaim the work of his hands.” This beautiful statement from Psalm 19:1 indicates one of the purposes of the created universe: to reveal the majesty of the Creator.

God made the universe unimaginably large. The universe contains objects of incredible size and mass at distances that the human mind cannot fully grasp. When we consider the power of the Lord who made all this, we cannot help but feel humbled.

Let’s start close to home, with a relatively small astronomical object. The moon is the nearest (natural) celestial body. The moon orbits at an average distance of 240,000 miles from the Earth. On the one hand, this is a tremendous distance. On the other hand, it is not so far as to be totally incomprehensible; some cars have that many miles on them.

The sun is about 400 times more distant than the moon. At the incredible distance of 93 million miles, we cannot fully appreciate just how far away the sun is. An analogy may be helpful. How long would it take to drive 93 million miles? If a person were to drive 65 miles per hour, it would take 163 years to drive this distance. We couldn’t drive this far in our lifetime.

The sun is far from the Earth, and yet the Earth is much closer to the sun than Pluto, a tiny frozen world at the outer edge of the planets of the solar system. Pluto (on average) is about 40 times farther away from the sun than the Earth is. Traveling at 65 miles per hour, it would take about 6,500 years to reach Pluto. The solar system is truly vast; if it had been the only thing God had made, we should certainly be impressed. Yet, God has created on even larger scales. Consider the distances between the stars.

Let’s start with the nearest star system to the Earth (besides the sun), the Alpha Centauri system. The distance to this system is about 25 trillion miles. Such a number has little meaning to most of us; who can comprehend 25 trillion miles?

To help grasp this to some extent, let’s imagine that we had a miniature scale model of the solar system with Pluto’s orbit being only one foot in diameter. The sun would be approximately in the center, and the Earth would be just over an eighth of an inch away from the sun. The sun itself would be smaller than the period at the end of this sentence. Where would we place the next nearest star in our one-foot scale model solar system? At this scale, Alpha Centauri would be over half a mile away, and that’s just the nearest star system. Our galaxy is comprised of countless numbers of stars at much greater distances. Using our one-foot scale model solar system, the galaxy would be larger than the Pacific Ocean!

Adapted from The Splendor of God’s Creation by Dr. Jason Lisle.