A GEOMAGNETIC STORM IS BREWING: NOAA has issued a G1-class geomagnetic storm warning for the hours ahead. Data from NASA's DISCOVR spacecraft suggest that a crack is opening in Earth's magnetic field, allowing solar wind to pour into the magnetosphere. This could trigger geomagnetic unrest around the poles and fuel a display of Arctic auroras on Aug. 24-25. Free: Aurora Alerts.
RAPIDLY GROWING SUNSPOT: Two days ago, sunspot AR2720 didn't exist. Now it sprawls across the more than 75,000 km of the sun's surface and has two dark cores as wide as Earth. Thierry Legault photographed the growing sunspot group on Aug. 25th from the Saint-Véran/Astroqueyras observatory in the French Alps:
"Sunspot AR2720 has metamorphosed since yesterday and it is now as large as the Earth!" says Legault. "I photographed the region using a Celestron C14 EdgeHD telescope and an Astrosolar filter."
The magnetic canopy of AR2720 is crackling with B-class solar flares--minor explosions hardly befitting a sunspot of its size. This is what we expect during solar minimum when even large sunspots tend to be quiet. Quiescence is not, however, an absolute rule. Less than one year ago, another "solar minimum sunspot" about the size of this one unleashed an X-class solar flare and produced a radiation storm so strong that energetic particles reached the surface of the Earth. Travel back in time using the Spaceweather Time Machine to review what happened: Sept. 10; Sept. 11, Sept. 12, 2017. These events make AR2720 worth monitoring.
Realtime Space Weather Photo Gallery
ATMOSPHERIC RADIATION UPDATE: Spaceweather.com and the students of Earth to Sky Calculus are in the middle of a cosmic ray ballooning campaign, visiting places we've been before to update our measurements of atmospheric radiation across the USA. On August 16th through 21st, we launched a series of balloons to the stratosphere from Bishop, CA; John Day, OR; and Wenatchee, WA. We found radiation levels increasing up and down the Pacific Coast. The latest data points are circled red:
Why is cosmic radiation increasing? Mainly, it's due to the solar cycle. As the sun plunges into a deep solar minimum, the sun's magnetic field is weakening. Solar wind pressures are declining as well. As a result of these changes, cosmic rays from deep space are finding it easier to penetrate the inner solar system. Surging cosmic rays hit the top of Earth's atmosphere, creating a downward spray of secondary particles and radiation that we detect using sensors on high-altitude balloons.
Our recent balloon launches from multiple US states as well as Sweden, Norway, Chile, Mexico and New Zealand confirm that cosmic rays are intensifying everywhere, but not by the same amount in all places. For instance, in the latest data we see that atmospheric radiation above Washington is almost 50% stronger than radiation above central California--a significant difference considering that the two launch sites are separated by only ~900 miles and 10 degrees of latitude. This shows that Earth's magnetic field is an uneven shield against incoming cosmic rays, protecting some places more than others.
Next week we'll be launching a cosmic ray balloon from Kansas and, soon thereafter, from Maine to extend our monitoring across the continental USA. Stay tuned.
FAR OUT OPTICS EXPERIMENT: Last week, the students of Earth to Sky Calculus flew a cosmic ray balloon to the stratosphere. A crystal globe went along for the ride. The young scientists wanted to see what Earth looked like when viewed through the spherical lens ... of Earth. Answer: very cool. Play the video to see for yourself:
You can have this globe for $169.95. The students are selling them to support their high-altitude balloon program. Each one comes with a greeting card showing the crystal sphere in flight and telling the story of its journey to the edge of space. All sales support the Earth to Sky Calculus cosmic ray ballooning program and hands-on STEM research.
Far Out Gifts: Earth to Sky Store
All sales support hands-on STEM education