Every so often a weather forecast will be dead-on, and you rub your chin amazed that anyone could predict something so fluid so accurately. That’s what happened last night with the aurora. NOAA’s Space Weather Prediction Center, which uses data from several satellites, predicted minor auroral storming for locations in Canada and possibly the northern tier of states in the U.S. I checked the auroral oval map and prospects looked good.
Thanks to my daughter Maria, who worked late and then came home to watch Paranormal Activity with me, I was up much later than usual. It was nearly 1 a.m. when the movie ended, but before going to bed, I gave the sky a quick look. To my disbelief and contrary to all forecasts (yes, it goes the other way, too!) the sky was clear. No northern lights though. I took the scope out for a look at Saturn, which really looked cool paired up with the nearly equally bright star Spica in the southeastern sky. The duo’s a real eye-grabber. I hope you get to see them soon.
Maybe a half hour later, after some clouds came and went, a glow started up in the northern sky. One way to tell the northern lights from local light pollution is to note the appearance of clouds. If they’re glowing too, you’re seeing reflected light from a nearby town or brightly-lit shopping center or business, but if the clouds are silhouetted against a brighter backdrop, there’s a good chance that light is aurora. I pulled out binoculars, looked low in the north and saw silhouettes. Yes!
While this display never amounted to much, it’s been a long time since we’ve had any. Frankly, I was thrilled, and yet by 3 it was already over. Tonight’s forecast calls for ‘quieter’ conditions as the effects of recent solar outbursts taper off. Like the demon in Paranormal Activity, the aurora’s visits are few and at odd hours.
I came across an interesting press release yesterday about a combined NASA-ESA (European Space Agency) proposed mission to study Jupiter’s four biggest moons with particular emphasis on Ganymede and Europa. Called the Europa Jupiter System Mission but with no launch date yet set, two separate probes would go into orbit around two of Jupiter’s most intriguing moons. Using a suite of instruments, the craft would study and photograph the moons’ surfaces and scope out their internal layers with radar that can penetrate beneath the crust to sub-surface oceans known to exist on both worlds.
Although the surfaces of both moons are frigidly cold, their interiors have been warmed byÂ flexing caused by their gravitational interactions between Jupiter and its other large moons. A paper clip bent quickly back and forth until it becomes warm to the touch is a helpful analogy. Heating, which could spawn deep volcanic activity, melts the ice sandwiched between the core and crust, creating an ocean of liquid water. And as you and I know well, life loves water. Might there be colonies of water-born microbes munching away at dissolved minerals inside Europa 500 million miles from the sun?
While the orbiters won’t be able to answer that question, every journey requires that a first step be taken, followed by another and another, until we discover what might be hidden from view.