Reference Point

The universe continually reminds me of how little I know, how little I pay attention.  This week's teachers are a pair of celestial bodies - Jupiter, and the Moon.

I am somewhat embarrassed to say that my understanding of the moon's pattern of motion was that it orbited around the earth, went through phases of lighting that had something to do with its orientation to the sun and that it moved around in the sky - sometimes it would be visible at night, sometimes during the day, sometimes in the morning, others in the evening, and that sometimes it was closer to earth than other times.

It was only a few years ago that I watched the full moon out my window about 6 pm rising over an Alaskan mountainside and thought that I'd stake it out the next night to take a photo.  But the next night the moon was nowhere in sight at 6 pm, and when it did appear, it wasn't in the same place relative to the mountain.  Of course, all this was completely predictable, but I had never paid enough attention to understand it.

Four nights ago, I was outside at 8 pm, and could see two objects in the hazy city sky -- Jupiter, and right next to it, the bright, full moon.  I can't explain it, but there's something majestic and compelling about the moon and a bright planet together in the sky.

Two nights later, I was again outside at 8 pm, and spotted Jupiter high in the sky - but no moon.  "Oh, there it is," quite a ways down toward the horizon.  Then I understood what was going on - the moon was coming up later each day, and the relatively fixed position of Jupiter gave me a good reference point to see the degree of change.

Tonight, after work, a gym workout, and dinner, we were once again out at 8 pm.  The sky was hazy with moisture, but I could see Jupiter high overhead.  The moon was nowhere in sight as we walked up through downtown Silver Spring.  Then I spotted a fuzzy glow just above the horizon, where the moon was finally coming up.  Tomorrow, by 8 o'clock in the evening, it won't be up at all.

After 50+ years, I now have some awareness about the direction and magnitude of the moon's motion relative to the earth.  Now, when I see the moon, I'll have a general idea of where it will be in the sky the next day.  Not hugely important, perhaps, but it feels good to know that, and I'm glad I was paying attention these past few evenings.