THE SOLAR WIND HAS ARRIVED: Arriving some hours earlier than expected, a stream of fast-moving solar wind has reached Earth. The gaseous material is flowing from a wide hole in the sun's atmosphere, and could engulf our planet for several days. NOAA forecasters estimate a 55% chance of G1-class geomagnetic storms on April 10th and 11th as Earth moves deeper into the stream. Free: Aurora Alerts.
The false-color image, above, from NASA's Solar Dynamics Observatory shows where the solar wind is coming from. Researchers call this a "coronal hole." It is a wide region where the sun's magnetic field has opened up, allowing solar wind to escape. Why are coronal holes dark? Because the hot glowing gas that normally fills the void is gone ... to Earth.
RED SPRITES AND THE PLEIADES: Last week in the Czech republic, Martin Popek photographed a pair of red sprites leaping up from a thunderstorm 375 km away at the Czech-German border. "They were reaching toward the Pleiades star cluster--a very pretty sight," he says. "Sprite season has begun!"
Over the years, Popek has photographed hundreds of sprites from his private observatory in Nýdek. These are unusual, however, because of the date they appeared. "I photographed them on April 4th," he explains. "Sprites usually appear in late spring or summer when thunderstorm season is underway. These are quite early."
Sometimes called "space lightning," sprites inhabit the upper atmosphere alongside auroras and noctilucent clouds. Unlike ordinary lightning, which lance down from thunderstorms, sprites fly up. Some researchers believe sprites are linked to cosmic rays: subatomic particles from deep space strike the top of Earth's atmosphere, producing secondary electrons that spark the eerie red forms.
The link to cosmic rays is particularly interesting at this time. Recent measurements by space weather balloons and NASA spacecraft show that cosmic radiation is increasing. This is largely due to the decline of the solar cycle. Flagging solar wind pressure allows more cosmic rays into the inner solar system. If sprites and cosmic rays are truly linked, we may be seeing many more of both in the years ahead. Stay tuned.
MOTHER'S DAY IS LESS THAN 5 WEEKS AWAY: Are you looking for a far-out Mother's Day gift? Consider this: On March 5, 2018, the students of Earth to Sky Calculus flew a cosmic ray balloon to the stratosphere, more than 94,000 feet above Earth's surface. Something for Mom went along for the ride:
The students are selling these pendants as a fund-raiser for their cosmic ray monitoring program. You can have one for $79.95. Each pendant comes with a greeting card showing the jewelry in flight and telling the story of its journey to the stratosphere and back again. Mom-satisfaction guaranteed!
Far Out Gifts: Earth to Sky Store
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