SOLAR MINIMUM CONDITIONS ARE IN EFFECT: The sun has been without spots for 16 consecutive days--a sign that Solar Minimum is underway. Many people think Solar Minimum is uninteresting. Not so. This phase of the solar cycle brings extra cosmic rays, long-lasting holes in the sun's atmosphere, and a possible surplus of noctilucent clouds. Aurora Alerts: SMS text, email.
RED AIRGLOW MAKES WAVES: Last week a line of strong thunderstorms passed north of Texas. Thomas Ashcraft saw the whole sky ripple in response. "I photographed a dramatic display of mesospheric gravity waves," he says. "This movie compresses an hour of ripples into just over 20 seconds."
The red light in the sky is airglow--a faint aurora-like phenomenon caused by chemical reactions in the upper atmosphere. These reactions get started during daylight hours when the atmosphere is bathed in strong UV radiation from the sun. On very dark nights we see the afterglow, colored green by oxygen atoms 90-100 km high or, in this case, red by hydroxyl molecules 86-87 km high.
The ripples come from thunderstorms. Gravity waves propagating up from powerful storms can impress airglow with a dramatic rippling structure. From space, the waves look like a giant atmospheric bull's eye.
Realtime Airglow Cloud Photo Gallery
Free: Spaceweather.com Newsletter
"ELECTRIC BLUE" MEETS ACTUAL ELECTRICITY: Every summer high above the North Pole, wisps of water vapor rise to the top of the atmosphere and crystallize around specks of meteor smoke. The resultant noctilucent clouds (NLCs) are often described by observers as "electric blue," similar in hue to an electric spark. Yesterday, electric blue met actual electricity in the skies over Kiel, Germany:
"It was a beautiful summer night with several small thunderstorms," says photographer Laura Kranich. "Pale rippling noctilucent clouds appeared above the thunderheads as lightning struck the ground below. What an incredible sight!"
What are noctilucent clouds doing in Germany? 2019 appears to be a special year for NLCs. The polar clouds are reaching down to southern latitudes, putting on a good show long before the summer season for NLCs nears its typical peak in mid-July. Studies have shown that noctilucent clouds sometimes intensify during Solar Minimum. Solar Minimum conditions are in effect now, and may be partly responsible for the unusual early-season sightings.
Realtime Noctilucent Cloud Photo Gallery
Free: Spaceweather.com Newsletter
A GIFT FROM THE EDGE OF SPACE: On August 16, 2018, the students of Earth to Sky Calculus launched a cosmic ray balloon to the stratosphere. This unique laser-etched Moon cube went along for the ride, ascending to an altitude of 101,140 feet:
You can have it for $119.95. The students are selling these cubes as a fund-raiser for their cosmic ray ballooning program. It's an authentic representation of the Moon, with all of the craters, mountains and lava plains accurately portrayed.
Each Moon-cube comes with a unique gift card showing the item floating at the top of Earth's atmosphere. The interior of the card tells the story of the flight and confirms that this gift has been to the edge of space and back again.
Far Out Gifts: Earth to Sky Store
All sales support hands-on STEM education
Realtime Space Weather Photo Gallery
Free: Spaceweather.com Newsletter