Orbits

I was walking Shelby this evening and watching the early evening sky, thinking, “Wouldn’t it be interesting if I happened to see the International Space Station fly overhead again?”

Then, as if I'd willed it to happen, it gently glided past overhead. I’ve seen it three times now completely by accident. Now I can say there is definitely a pattern in terms of the time of day it passes overhead; early evening.

The first time I saw it was at the Summer Sessions concert at Ambleside, and the second time was while I was standing in my backyard waiting for my dog. Tonight I noticed another pattern; its navigation through the stars. At Ambleside I was a bit disoriented in terms of where exactly North was located, partly because I don’t live on the North Shore, and partly because we were in the park and I had no roads with which to locate myself. At the time I judged the ISS to be moving from NW to SE.

A few days later when viewing the ISS from my backyard, it was definitely more West to East. It passed just South of the handle of the Big Dipper, then seemed to run parallel to E. 33rd Avenue until it faded quite quickly from view as the Sun set on the much higher Space Station orbit. After seeing the West to East arc I seconded-guessed myself for a moment and thought I’d been wrong about the trajectory of the Ambleside fly-past.

But way back when, I do remember that I thought I was wrong once, but alas, I was mistaken. :-)

Upon seeing the ISS fly over yet again this evening, I can now say with surety that its arc was different from the 33rd Avenue parallel of a couple of nights ago. I first noticed it at 8:20 p.m. PDT; a small bright orb devoid of blinking aircraft lights traveling at a very uniform pace. (That thing must get phenomenal gas mileage, doing steady 'double nickels' down the interstellar interstate. The ultimate cruise control.) It approached the tip of the Big Dipper’s handle, but by then it was already heading off that bearing. It seemed to crest right over our back deck and it finally vanished from my view between two massive Cedar trees two properties to my South.

Theory proven; it’s orbit isn’t static. It’s changing.

One more thing I noticed tonight was that another smaller, dimmer satellite was leading the ISS across the sky, as if it was a tugboat pulling a freighter, tethered by an unseen thread.

The weather is supposed to be clear for the next 7 days according to the most recent forecast so I’m going to try to remember to watch for the Space Station each evening at around 8:15 or so. I want to see how the orbit evolves.