The ridiculously difficult landing of Rosetta Mission’s Philae probe on comet 67P ignited pondering fires of cosmic wonder – a topic I’ve been silent on far too long. Months ago I wrote a post about “baby steps” to the cosmos, followed by several more on identifying specific stars, planets and constellations. Doubtful that many people bothered to follow meticulous instructions for visual orientation, my fall back has always been enthusiastic encouragement to download Google’s Sky Map app. As I pointed my phone at tonight’s sky, it occurred to me – this is too easy. To”Google”, is to arrive at answers without the process of investigation. Sky apps are handy in a pinch, but rather like cheating on a final exam – how could I study for the test?
My mind drifted back to grade school, and it hit me – I’ll make my own Planisphere.
Planispheres have existed in one form or another for centuries – one disc over another, rotating on a central pivot. Or a “pocket” and “wheel” you slip into the pocket depending on where you are and what you want to see. I found the site linked below – step by step instructions for all your Planisphere needs. First you print a “pocket” based on your latitude, then you make “city” and “milky way” wheels. City wheels are basic orientation of the brightest objects as seen from your location. Milky Way wheels are full on representation of everything visible if you could view the night sky as if in a rural location, free of light pollution. The site gives latitudes and instructions for “traveling” star wheels – make Planispheres when you travel, or send them as Christmas gifts to anyone, anywhere.
Of course I could go out and buy a Planisphere, but that defeats the purpose. The point is to stop and think about your latitude, realizing it truly matters to the night sky. A Planisphere forces one to understand the cosmic drift and flow. Making one teaches far more than occasional posts or instant recognition Google ever could – a star wheel offers reasons, makes us think, and takes us back to the joy of discovery.