Various Thoughts - Astronomy News and Articles

Stable Solar System

I read an interesting, brief article in the March 2023 Reflector magazine, called "IS THE SOLAR SYSTEM STABLE?", exploring the question of whether our solar system should remain stable over very long periods of time. Author Berton Stephens gave a short summary of historical methods that have been used to calculate future astronomical positions. And then he discussed the challenges involved in modeling the solar system accurately.

To model the Sun, planets, 205 moons, 9 dwarf planets, and 35 minor planets larger than 160 miles across would require calculating 33,153 interactions for each step.

Stephens concludes:

To study the stability of the Solar System on a shorter time scale, Angel Zhivkov and Ivaylo Tounchev of Sofia University in Bulgaria pro- duced a model with simplifying assumptions that allowed them to run the program on a workstation in a reasonable amount of time. The run covers the next 100,000 years. During that time, the major planets’ average distances from the Sun and the eccentricities of their orbits vary by less than one percent. This indicates that our Solar System will be stable over that time period [....] Their work shows that, at least in the short run, the planets in our Solar System will continue their stately motion around the Sun, barring the arrival of an interloper from outside our system.

I found that interesting since I'm pretty sure that, if you had given me "the Sun, planets, 205 moons, 9 dwarf planets, and 35 minor planets" to arrange into a stable orbit, the solar system would have been doomed in its first millenium. Theologically, it should not suprise me that God's universe is orderly and stable, though also I believe that much of God's sustaining influence was removed at the Fall. Of course, secular cosmologists believe that 100,000 years is a "short run" of time, whereas Scripture teaches that the universe is less than 10,000 years old, at least from our frame of reference here on earth.

Planets in pretty much any order

An interesting article on earthsky.org last month:

Of 4 types of planetary systems, ours is rarest

The short version is that, as far as mass distribution of planets is concerned (i.e., the order of large and small planets) we are finding four different kinds of planetary systems in the universe: Those that are ordered the same as ours; those that are ordered the opposite of ours; those in which all the planets are the same mass; and all the other ones that don't fit into the above categories.

The question I'm asking (rhetorically) is, how could this state of affairs possibly fall out of the secular model of solar system formation? If the same natural processes are forming the solar systems out of basically the same condensing, rotating materials, how can we get a gas giant at the far end of one solar system, and at the near end of another, and in the middle of another?

The article suggests that the solution will be found in the mass of the individual accretion disk, and the amount of heavy elements found in it. Hints are given of some "testable predictions" that might possibly "hold up" in the future, but you have to read the original research papers to find out more about that.

NGC 3628 Galatic Merger?

When I was planning to target the Leo Triplet in one of my astronomy adventures, I came across an interesting note on this page:

NGC 3628: Hamburger Galaxy

The Hamburger Galaxy is known for its broad equatorial band of dust and a vast tidal tail, spanning approximately 300,000 light years. The dust band obscures the galaxy’s central region and the bright young stars that have formed in its spiral arms.

A spectroscopic analysis of the galaxy’s disk has revealed that the stars in NGC 3628 orbit in the opposite direction of the gas in the galaxy, likely as a result of a recent galactic merger.

From a secularist's perspective, it is a very odd thing that the stars and the gas of the galaxy are rotating in opposite directions, since the material would have all been rotating the same direction originally. From the creationist's perspective, it is just another fascinating bit of variety in God's universe. It will be interesting for me to find out if there has been or will be some further study of this "galactic merger" proposal to see if it is even plausible.