Recent Solar Activity

On Feb. 13th at 1738 UT, sunspot 1158 unleashed the strongest solar flare of the year so far, an M6.6-category blast. NASA’s Solar Dynamics Observatory recorded an intense flash of extreme ultraviolet radiation, circled below:

And then yesterday, June 7, the sun let loose what [BadAstronomer][1] termed a “ginormous” explosion.

A little less colorfully, BadAstronomer notes:

> What you’re seeing here is a solar flare (an enormous explosion of pent-up magnetic energy) coupled with a prominence (a physical eruption of gas from the surface). This event blasted something like a billion tons of material away from the Sun. Note the size of it, too: while it started from a small region on the Sun’s surface, it quickly expanded into a plume easily as big as the Sun itself! I’d estimate its size at well over a million kilometers across. It looks like most of the material fell back down to the Sun’s surface; that’s common, though sometimes such an event manages to blast the material completely away into space. The above video shows the Sun in the ultraviolet (304 Angstroms for those playing at home, quite a bit bluer than what the eye can naturally see) and is colored orange to make it easy to see.

[1]: http://blogs.discovermagazine.com/badastronomy/2011/06/07/the-sun-lets-loose-a-huge-explosion/

Solar Powered USB Charger

Ah, the dreams of going off-grid! More importantly, the ability to re-charge in the field when you’ve forgotten to charge fully before leaving home. AA batteries power my small camera and my field recorder, but my cell phone has a built-in battery.

There are a number of solar-powered chargers out there, and some are reasonably priced. There is, however, something incalculably alluring about finding one of those cheap lawn lighting kits, for say $10, and making your own solar charger. More importantly, it would be nice to begin to do such things with my daughter, so that she has a since of *making* things for herself.

Here’s the simplest DIY version I have been able to find: [[Metacafe video]](http://www.metacafe.com/watch/800000/solar_powered_usb_charger_cheap_and_easy_to_make/).