SOLAR WIND, INCOMING: A stream of solar wind is expected to graze Earth's magnetic field on June 25th or 26th, causing geomagnetic activity just below the level of a G1-class storm. The gaseous material is flowing from a southern hole in the sun's atmosphere. High-latitude sky watchers shouldbe alert for auroras, especially in the southern hemisphere where winter darkness favors visibility. Aurora alerts: SMS Text
RARE RED NOCTILUCENT CLOUDS: Noctilucent clouds are supposed to be electric blue, yet during the extreme NLC outbreak of June 21st, some observers in Europe saw a different color: red. "It happened around midnight," reports Marek Nikodem of Szubin, Poland. "The top of the clouds developed a reddish-purple canopy." It didn't last long, but he was able to photograph the amber crown before it faded away:
Above: Red and blue noctilucent clouds over Szubin, Poland. Credit: Marek Nikodem
Others saw them, too, including Piotr Majewski of Piwnice, Poland, and Peter Paul Hattinga Verschure of Deventer, The Netherlands.
"What creates this color?" asks Nikodem.
The answer is ozone--or rather, lack thereof.
Research in the 1970s revealed that much of the sunlight hitting noctilucent clouds first passes through Earth's ozone layer. Ozone absorbs red light, while allowing blue to pass--hence the usual color of the clouds. When the sun is hanging very low, however, reddened sunlight refracted through the dense troposphere can paint the tops of NLCs red, overwhelming the usual "ozone blue."
Above: Mostly red noctilucent clouds over Piwnice, Poland. Credit: Piotr Majewski
PS: Ozone isn't the only reason noctilucent clouds are blue. The clouds consist of tiny ice crystals about the size of particles in cigarette smoke. Cigarette smoke looks blue, too, and for the same reason. Tiny particles scatter blue light better than other colors.
Realtime Noctilucent Cloud Photo Gallery
Free: Spaceweather.com Newsletter
APOLLO 11 PROOF SILVER DOLLAR: To celebrate the 50th anniversary of the Apollo 11 Moon landing, the United States Mint has created a commemorative 2019 Proof Silver Dollar. We decided to celebrate even more by flying the coins to the edge of space. On June 13th, the students of Earth to Sky Calculus launched this 99.9% silver dollar 99,022 feet above Earth's surface:
You can have it for $179.95. The students are selling the coins to support their cosmic ray ballooning program. The silver dollar is curved and reproduces the helmet of astronaut Buzz Aldrin. Reflected in Buzz's visor are Neil Armstrong, the United States flag, and the lunar lander. The opposite side of the coin shows Neil's iconic footprint on the Moon. Each of these coins comes with a greeting card showing the item in flight and a certificate of authenticity.
Far Out Gifts: Earth to Sky Store
All sales support hands-on STEM education
Realtime Aurora Photo Gallery
Free: Spaceweather.com Newsletter
Realtime Space Weather Photo Gallery
Free: Spaceweather.com Newsletter