GEOMAGNETIC STORM WATCH: NOAA forecasters say there is a chance of minor G1-class geomagnetic storms on July 6th when a stream of solar wind is expected to hit Earth's magnetic field. The gaseous material is flowing from a cyclops-like hole in the sun's atmosphere. Aurora alerts: SMS Text.

AURORAS ON THE 4TH OF JULY: A CME that narrowly missed Earth on July 1st is still making auroras four days later. Greg Ash photographed the light show during the early hours of July 4th from Ely, Minnesota:

"It was a pleasure to watch three generations captivated by this beautiful pulsating colorful light show," says Ash. "The auroras were very visible to the naked eye."

The CME that caused the display was probably launched from the sun on June 28th by an erupting filament of magnetism. It wasn't squarely on the sun-Earth line and didn't actually strike our planet. Instead, as it passed by, it shoved dense solar wind plasma toward Earth; think of the wake of a passing speed boat. Ripples from the near miss sparked G1-class geomagnetic storms on July 2nd and July 4th.

"The twin storms not only produced beautiful auroras, but also they also moved magnetometer needles including my own here in the UK," reports Stuart Green who recorded the event:

The squiggles in Green's chart represent changes in ground-level magnetic fields caused by the CME. "The sensor is buried in my garden about 0.5 meters below the surface in an East/West orientation," he explains. "This allows very sensitive (sub nanotesla) measurements of magnetic declination during geomagnetic storms."

Green built his own magnetometer from scratch. Would you like to do the same? Here's how.

more images: from Jake Stehli of Winona, Minnesota; from Rocky Raybell of Keller, Washington; from Marybeth Kiczenski of Ludington, Michigan; from George Dunham of Crawford, Colorado; from Dwight Brady of Marquette, MI; from Sarah Goodwin of Mears, MI; from Thomas Spence of Tofte, MN; from Michele Sadauskas of Glidden, WI; from Matthew D. Moffet of Billings, Montana