Out at the unfashionable end of the Asteroid Belt, lies a seldom seen squashed spud of rock known as Sylvia. NASA has this:
Discovered in 1866, main belt asteroid 87 Sylvia lies 3.5 AU from the Sun, between the orbits of Mars and Jupiter. Also shown in recent years to be one in a growing list of double asteroids, new observations during August and October 2004 made at the Paranal Observatory convincingly demonstrate that 87 Sylvia in fact has two moonlets – the first known triple asteroid system. At the center of this composite of the image data, potato-shaped 87 Sylvia itself is about 380 kilometers wide. The data show inner moon, Remus, orbiting Sylvia at a distance of about 710 kilometers once every 33 hours, while outer moon Romulus orbits at 1360 kilometers in 87.6 hours. Tiny Remus and Romulus are 7 and 18 kilometers across respectively. Because 87 Sylvia was named after Rhea Silvia, the mythical mother of the founders of Rome, the discoverers proposed Romulus and Remus as fitting names for the two moonlets. The triple system is thought to be the not uncommon result of collisions producing low density, rubble pile asteroids that are loose aggregations of debris.
Ah, yes, it’s ‘collisions’ again. But wait, there’s some order in the chaos here, discerned by Stuart ‘Oldbrew’, who says:
Romulus and Remus are 3:8 in orbits = 5 conjunctions
Re:Ro mass ratio is 1:1.274 using Wiki = ~root phi
The orbital ratio 3:8 is of course two Fibonacci numbers, separated by a third, 5. The conjunctions Stuart refers to, occur every 33 * 87.6 / (87.6 – 33) = 52.945 hours. So 5 conjunctions occur every 284.725 hours. During that period, Romulus orbits 284.725/87.6 = 3.02 times and Remus orbits 8.02 times. This tells us that the precession of the conjunction cycle is rapid, completing every 50 conjunction cycles.
I wouldn’t have noticed Sylvia if She hadn’t turned up in a table of orbital distances (from the Sun) generated when I worked out an equation to improve Bodes Law. That’s a heuristic which quite accurately predicts the orbital distances of celestial bodies out as far as Uranus, whereafter the equation goes rapidly of the rails, missing Neptune by a loooong way. My new equation pinpoints Neptune well, skips the Neptune orbit-crossing dwarf planet Pluto and goes on to nail Makemake, and comes close to hitting Eris. The discoverer of those two, Mike ‘Plutokiller’ Brown is in the news currently with his conjecture for ‘Planet 9’.
As you’d expect, my equation uses phi and associated number terms, and with a nod to gravity, a power-law progression based on powers of 2. I’ll write a post about that soon.