BRIGHTENING COMET: Approaching Comet 21P/Giacobini-Zinner has brightened by a full magnitude since Aug. 15th, according to Odd Trondal of Oslo, Norway, who has been monitoring the comet's nucleus almost daily for more than a month. This bodes well for Giacobini-Zinner's 0.39 AU close approach to Earth on Sept. 10th when it is expected to reach almost-naked eye visibility. Browse: photo gallery, 3D orbit
THE SOLAR WIND HAS ARRIVED: Earth is entering a stream of high-speed solar wind, and this is causing geomagnetic activity around the Arctic Circle. Today in Rovaniemi, Finland, Jani Ylinampa woke up early to photograph the green glow of auroras mixing with morning twilight:
"A brief but vivid display of northern lights lit up the sky during to early hours, showing that autumn has indeed come to the Arctic Circle," says Ylinampa.
The gaseous material now buffeting Earth's magnetic field is flowing from a wide hole in the sun's atmosphere. It is so wide, Earth could be inside the stream for days, maybe even the rest of the week. NOAA forecasters estimate a 50% chance of continued geomagnetic disturbances on August 20th and 21st. Free: Aurora Alerts.
GIANT 'ELVE' OVER RUSSIA: On Aug. 16th, high above a thunderstorm in central Russia, an enormous ring of light appeared in the night sky. Using a low-light video camera in the town of Irbit, amateur astronomer Ilya Jankowsky photographed the 300 km-wide donut hovering near the edge of space:
"It appeared for just a split second, surrounding the horns of Taurus," says Jankowsky.
This is an example of an ELVE (Emissions of Light and Very Low Frequency Perturbations due to Electromagnetic Pulse Sources). First seen by cameras on the space shuttle in 1990, ELVEs appear when a pulse of electromagnetic radiation from cloud-to-ground lightning propagates up toward space and hits the base of Earth's ionosphere. A faint ring of deep-red light marks the broad 'spot' where the EMP hits.
"For this to happen, the lightning needs to be very strong--typically 150-350 kilo-Ampères," says Oscar van der Velde, a member of the Lightning Research Group at the Universitat Politècnica de Catalunya. "For comparison, normal cloud-to-ground flashes only reach 10-30 kA."
ELVEs often appear alongside red sprites, which are also sparked by strong lightning. Indeed, Jankowsky's camera caught at least two clusters of sprites dancing nearby.
ELVEs are elusive--and that's an understatement. Blinking in and out of existence in only a millisecond, they are completely invisible to the human eye. For comparison, red sprites tend to last for hundredths of a second and regular lightning can scintillate for a second or more. Their brevity explains why ELVEs are a more recent discovery than other lightning-related phenomenon. Learn more about the history and physics of ELVEs here and here.
LASER-ETCHED MOON CUBE: 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 $149.95. 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
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Realtime Space Weather Photo Gallery
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