BLANK SUN: Giant sunspot AR2665 has rotated onto the far side of the sun. It is gone, leaving behind ... nothing. The face of the sun is blank. With the sunspot number back at zero, the sun's march toward Solar Minimum has resumed. Free: Solar Flare Alerts
NORTHERN CORONAL HOLE: A hole in the sun's atmosphere has opened up and it is spewing solar wind into space. NASA's Solar Dynamics Observatory is monitoring the structure, which sprawls across nearly half of the sun's northern hemisphere:
This is a coronal hole (CH), a region where the sun's magnetic field peels back and allows solar wind to escape. A stream of solar wind flowing from this hole is expected to reach Earth on July 21st, bringing a 40% chance of geomagnetic activity. High-latitude sky watchers should be alert for auroras when the solar wind arrives. Free: Aurora Alerts
NOCTILUCENT CLOUDS VS. AURORAS: On July 17th, during a geomagnetic storm, Ruslan Merzlyakov of Nykøbing Mors, Denmark, went to the beach after dark, hoping to see some patches of green in the sky. Instead, he witnessed a spectacular display of electric blue:
"I did not see any auroras, but there were some very nice noctilucent clouds (NLCs)," says Merzlyakov.
At about the same time in Germany, Laura Kranich caught them both. "I photographed noctilucent clouds with auroras shimmering overhead," she says. "It was a space weather duet."
The auroras have faded as Earth exits the wake of a CME. However, the noctilucent clouds seem to be intensifying. On July 17th and 18th, European observers have seen the silvery ripples of frosted meteor smoke as far south as France. Sunset sky watchers should be alert for more. Observing tips: Look west 30 to 60 minutes after sunset when the sun has dipped ~10o below the horizon. If you see luminous blue-white tendrils spreading across the sky, you may have spotted a noctilucent cloud.
Realtime Noctilucent Cloud Photo Gallery
SOLAR ECLIPSE SPACE PENDANTS: Would you like to support our Solar Eclipse Balloon Network? Here's one way: Buy a space pendant. This solar eclipse-themed necklace flew to the stratosphere on July 2, 2017, attached to the payload of an Earth to Sky Calculus space weather balloon:
The payload contained more just like it. If you buy one now for $79.95, we will fly it back to the stratosphere during the Great American Solar Eclipse on August 21, 2017, where it will be enveloped by the Moon's cool shadow above our launch site in Oregon. No additional charge! Just make a note in the COMMENTS BOX of the shopping cart: "Please fly my pendant into the eclipse!" 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.
More items from the edge of space may be found in the Earth to Sky Store. All proceeds support atmospheric radiation monitoring and hands-on STEM education.
Far Out Gifts: Earth to Sky Store
All proceeds support hands-on STEM education
Realtime Space Weather Photo Gallery