Hey, everyone! Thanks for stopping by.
Well, guess what happened. Yesterday afternoon, my daughter and I walked down the hill to the supermarket to get a couple of straggling things that I forgot. It always seems to be cheese. She’d had a long day at school, so as we walked, we talked about other things. Soccer, music, cheese (various types, applications, and uses thereof). On the way back up the hill, the afternoon had started to change into evening. Ahead of us were the gorgeous winter stars, and the constant and welcoming stars in Cassiopeia’s “W” asterism were just starting to blink into into the sky. You read that right, after weeks of clouds, the sky was clear, and we could see… stuff!
Over our shoulder, were Mars and Venus. As we made our way higher up the hill, the moon rose above the houses at the bottom until it was beside them, its full face visible in the dusk. The thin crescent was lit by the sun, the rest by earthshine, sunlight reflected off the earth to the moon and back again to our eyes. It was a gorgeous evening, and the lineup was, too, just as beautiful as promised.
Tonight, the moon, which, thanks to its revolution around the earth, appears to move backward across the sky relative to the rest of the stuff we can see, will be higher, in the triangle formation we talked about the other day. Maybe today’s a good day for this week’s word of the week!
As the moon makes its way across the sky each month, it passes various things as we see them from our lawns and couches, planets and stars, mostly. These days, with the Mars and Venus in the evening’s skies, the moon makes its way past them right in front of our eyes every four weeks. You might have noticed from reading here, or seeing them yourself, that on one of those nights, the moon is closer to them than on the other couple when they’re cruising past each other.
That closest point is an appulse. An appulse, is an object’s closest point to another, or to a couple others, as in the case of tonight’s Moon-Mars-Venus triangle. Last night was not as close, tonight real close, tomorrow not as close again. This is, like so much of astronomy and life, a matter of perspective. Just because the three are close, appulsing each other in our sky, does not necessarily mean all of the telescopes and explosive space modulators on Mars will see the appulse tonight.
Appulse another one of these fancy-seeming words for simple things, but a good one, and one that’s improved by not being in my computer’s spelling dictionary. This word comes from Latin, meaning to move toward. You might really like the adverb form, appulsively. “Later this month, the moon will move appulsively toward Aldebaran, and occult it!”
It’s snowing here today, so I don’t think I’ll have much luck seeing tonight’s alignment. Last night, though, I grabbed this shot of the three. It really was something. I hope you can see them tonight.
Thanks for stopping by. I’m going to get to the appulse of some more coffee. Clear skies, everyone!