EXITING THE SOLAR WIND STREAM: Earth is beginning to exit a stream of solar wind that sparked G1-class geomagnetic storms when it arrived on Dec. 5th. NOAA forecasters say there is a 55% chance of minor geomagnetic storms on Dec. 6th as Earth leaves the gaseous material. Arctic sky watchers should remain alert for auroras as the solar wind speed subsides. Free: Aurora Alerts.
ATMOSPHERIC RADIATION IS INCREASING: Since the spring of 2015, Spaceweather.com and the students of Earth to Sky Calculus have been flying balloons to the stratosphere over California to measure cosmic rays. Soon after our monitoring program began, we quickly realized that radiation levels are increasing. Why? The main reason is the solar cycle. In recent years, sunspot counts have plummeted as the sun's magnetic field weakens. This has allowed more cosmic rays from deep space to penetrate the solar system. As 2017 winds down, our latest measurements show the radiation increase continuing apace--with an interesting exception, circled in yellow:
In Sept. 2017, the quiet sun surprised space weather forecasters with a sudden outburst of explosive activity. On Sept. 3rd, a huge sunspot appeared. In the week that followed, it unleashed the strongest solar flare in more than a decade (X9-class), hurled a powerful CME toward Earth, and sparked a severe geomagnetic storm (G4-class) with Northern Lights appearing as far south as Arkansas. During the storm we quickened the pace of balloon launches and found radiation dropping to levels we hadn't seen since 2015. The flurry of solar flares and CMEs actually pushed some cosmic rays away from Earth.
Interestingly, after the sun's outburst, radiation levels in the stratosphere took more than 2 months to fully rebound. Now they are back on track, increasing steadily as the quiet sun resumes its progress toward Solar Minimum. The solar cycle is not expected to hit rock bottom until 2019 or 2020, so cosmic rays should continue to increase, significantly, in the months and years ahead. Stay tuned for updates as our balloons continue to fly.
Technical note: The radiation sensors onboard our helium balloons detect X-rays and gamma-rays in the energy range 10 keV to 20 MeV. These energies, which span the range of medical X-ray machines and airport security scanners, trace secondary cosmic rays, the spray of debris created when primary cosmic rays from deep space hit the top of Earth's atmosphere.
Realtime Space Weather Photo Gallery
FAR OUT CHRISTMAS GIFTS: Helium doesn't pay for itself. That's why the students of Earth to Sky Calculus fly cool things to the edge of space on board their cosmic ray balloons--so you can buy them in our Christmas Store:
Crystal balls, solar eclipse pendants, pyramids, pickles and much more: they've all been to the edge of space and back, and they all make great holiday gifts. Every dollar spent in the store supports STEM education and high-altitude space weather research. Shop now!
Far Out Gifts: Earth to Sky Store
All proceeds support hands-on STEM education
MAGNETIC STORM: A stream of fast moving solar wind engulfed Earth's magnetic field on Dec. 5th, sparking a G1-class geomagnetic storm. In Murmansk, Russia, photographer Дмитрий Рак knew the stream had arrived when the sky overhead filled with luminous swirls of green:
"[Bright moonlight illuminated the snowy trees, which framed] the very beautiful display," says Рак.
Thousands of miles away in Preston UK, the sky was overcast, but Stuart Green also knew that a geomagnetic storm was underway. His backyard magnetometer revealed the telltale vibrations of Earth's magnetic field:
"After days of relative calm, the predicted high speed solar wind from a coronal hole finally arrived, sparking a G1 storm and polar aurora," he says. "It's always so very satisfying to see the wiggles developing on screen during such events, no matter what the terrestrial weather is doing."