I know, today’s supposed to be my nominal Flash Fiction day, but that’s going to have to wait. (I’m working on it.) In the meantime, celestial mechanics grabbed my attention and gave me a treat.
Mercury’s hard to see. It’s never far from the sun, so the only time to see it is right after sunset or right before sunrise, when the sky is still partially illuminated. The times when it’s furthest from the sun from our point of view is called “greatest elongation” and sometimes even that doesn’t help. If the plane that we’re seeing Mercury in is shallow to the horizon (it changes as the Earth moves around the sun because the earth’s axis is tilted) it’s almost impossible to see.
Dim object in a still bright sky is not a good thing.
Mercury’s was at greatest elongation a day or two ago but this time the plane of the ecliptic is up high, and to boot you’ve got Venus really close (called a “conjunction”) which makes it easier to know where to look for Mercury, because Venus is really stinkin’ bright even when it’s close to the sun.
I knew all of this, but I have hills to my west and it’s been cloudy and hazy. I was seeing pictures that others were taking and figured if I got a clear night I would go over to a local spot where there’s a nice hill with a decent western horizon. Tonight might have been a good night, but I had other things to do and wasn’t going to be home until nearly an hour after sunset.
Then, driving home, headed west…
Hanging in the sunset, right next to Venus shining so bright it looks like the landing lights on a 747, was Mercury, more clear to see than I’ve ever imagined. Mercury was as clear as day, even dealing with traffic and street lights and the lights of oncoming cars.
More importantly, as I pulled up at home and looked again, the pair was more than high enough even to be seen over the hills to my west! Run into the house, kiss The Long-Suffering Wife, grab the camera (fortunately still set up on the tripod for Comet Lovejoy hunting), and sprint back out into the front yard.
I think that I’ve only seen Mercury with the naked eye once before, maybe twice. No, just once. Anyway, it was hard to miss tonight. Spectacular!
180 mm zoom, 1/20 second
Remember to click on the image to see the full-sized versions.
300 mm zoom, 1/4 second
154 mm zoom, 1/3 second
192 mm zoom, 1 second
As it got darker, you can see a few other stars starting to pop out, like the one that’s disappearing underneath the phone wires at the bottom and the one that’s just coming into view at the top of the frame.
If it’s clear out tomorrow, the next goal might be to try to get a wider picture — Mars is off to the upper left but would require a much wider angle picture. Worth trying. Of course, if I really had some good hear set up and could get Mars included in the picture, Neptune is fairly close to Mars… It would be fantastic to get all four of these planets in one picture, but that might be a stretch for me with just a camera on a tripod.
Mercury will be slowly pulling away from Venus and sinking back down toward the sun over the next couple of weeks. If you get a chance in the next couple of days to take a look and you’ve got a clear western horizon at sunset, take a gander at Mercury, the closest planet to the sun!
Now, back to writing Flash Fiction…