(Easter) Egg Moon

April 18, 2011 Full moon

Having a five-week old in the house guarantees that if you need to be awake at night to do something, say, take pictures of the full moon, you’ve got a pretty good chance. Of being awake, that is. Staying awake long enough to put the baby to sleep, get downstairs and outside with your camera and spotting scope, well, that’s another story. But Sunday night/Monday morning I was able to pull it off, and here is the result:

As usual, click on the image to see a larger version.

I had missed the official moment of full by a good four/five hours, so you can just see a bit of shadow creeping in at top right (north and a bit east). That teeny hint of shadow is the “sunset” line on the moon, the advancing lunar terminator that will bring the Mare Crisium into shadow in a couple of days (see screenshot below of the “current” moon phase, with the sea of crises just entering the shadow–I’m writing this on my lunch break).

The same thing happens in reverse as the “sunrise” terminator sweeps across the new moon bringing Mare Crisium to view when the moon is just a couple of days old.

First in, first out, that’s the moon’s inventory control system.

Here are some screenshots of a few iPad apps I use to help me find my way around the moon. The first is a moon-at-a-glance style view from the MoonPhase app. It shows lots of useful data, including name of this month’s moon (you can choose which naming system you prefer), current (or time-specified) phase, location in zodiac, position in sky relative to your horizon/zenith, rise/set times, and ephemeris for the current or specified time/date:

It’s really quite a lot of data, and very customizable. You can view calendars of upcoming or past moon phases, the whole nine yards.

Another app I use to help me navigate the moon is MoonHD. It shows a zoomable map of the moon with terrain features labeled; you can orient the moon as it appears from your location, or from space, or from an earth telescope; you can overlay a compass that shows the relative positions of the sun and moon (although it always shows only current relative positions, no matter what time/date/illumination you’ve got dialed in):

And, last but not least, there’s MoonAtlas, which I use for its libration calendar:

This one even looks like a good old moon atlas, and the libration calendar helps me be sure I’m orienting the image correctly. For example, reviewing the graph I can see that the northern limb of the moon is tilted nearly 7 degrees toward Earth at the time of full moon, so that’s quite a favorable libration for viewing the north pole. The moon’s longitudinal (side to side) tilt is only about 2 or 3 degrees, though.

These three apps are almost as useful as/maybe more useful than my beloved, and very old-school, Rükl atlas, which is apparently out of print again. But the main apps I use to enjoy the moon are even more old school than that: my brain, my eyes, and my telescope. With those, I can do just about anything; with a digital camera and these brave new world apps, I can add to the experience, but they don’t replace me bringing my sensory and cognitive apparatus into direct contact with the moon’s image in the eyepiece. It’s my thoughts/perceptions/enjoyment of the spectacular nature in the night-time sky that I’m after; the technology is just a way of accessing and enhancing those thoughts, those perceptions, that enjoyment. No matter how good they are (and they’re good–really, really good), nothing beats that immersive experience of Going Outside.