NEW! STARLINK TRAIN ALERTS: You've probably heard about Starlink's "string of pearls" -- a bright train that forms in the night sky for a few days after the launch of each new batch of satellites. Now you can see one. Our Backyard Astronomy Alert Service now includes Starlink Train Alerts. You'll receive a text and email whenever a string of pearls is about to fly over your backyard. Sign up now.
RED AND GREEN AIRGLOW: On Friday night in Jouhe, France, Nicolas Rossetto pointed his camera out of a roof window to catch the sky before wildfire smoke moved in. He saw something better than a clear sky: waves of red and green airglow rippling across the stars:
"What a display!" says Rossetto. "The ripples were quite striking."
Airglow is the atmosphere glowing in the dark. By day, sunlight energizes molecules at the edge of space; at night they release that energy as soft light. The ripples are atmospheric gravity waves launched by storms on Earth sweeping upward through the airglow later.
Here's what makes Rossetto's images special: they show two layers at once. The green light comes from oxygen atoms about 95 km high. The red comes from OH (hydroxyl) molecules in a layer just below, near 87 km. Look carefully at the animation: the red and green ripples share the same wavelength and move at the same speed. That's because a single gravity wave is passing through both layers, lighting them up in different colors as it climbs toward space.
Most cameras never see the red. OH is actually the brightest airglow emission of all, but it shines mainly in the near-infrared--exactly where the IR-cut filter inside a standard camera blocks the view. Rossetto's Canon 6D has been modified with that filter removed, opening a window most photographers don't have.
Realtime Airglow Photo Gallery
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STERLING SILVER SPACE CAT PENDANT:Are you looking for a far-out gift? Consider the Sterling Silver Space Cat. On July 22nd, the students of Earth to Sky Calculus launched it to the stratosphere onboard a cosmic ray research balloon:
You can have it for $139.95. This feline astronaut is made of genuine sterling silver and hangs from a matching 18-inch sterling silver chain. It is a purrfect birthday, anniversary or belated graduation gift.
The students are selling space pendants to pay the helium bill for their cosmic ray ballooning program. Each one comes with a greeting card showing the jewelry in flight and telling the story of its trip to the stratosphere and back again.
Far Out Gifts: Earth to Sky Store
All sales support hands-on STEM education
Realtime Aurora Photo Gallery
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Realtime Space Weather Photo Gallery
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