GEOMAGNETIC STORMS TODAY: Minor (G1) to moderate (G2) geomagnetic storms are likely on Oct. 27th as Earth continues to move through a fast-moving stream of solar wind. Polar sky watchers should remain alert for auroras. Free: Aurora Alerts.
CRAZY PINK AURORAS: During the ongoing solar wind storm, observers around the Arctic Circle have been reporting auroras of an unusual color. "Crazy pink," says Frank Meissner, who took this picture from Tromsø, Norway, on Oct. 26th:
"It was awesome," he says. "Flash-like bursts were zooming all over the sky."
Also watching from Tromsø, veteran observer Terence Murtagh says "even with many hundreds of aurora sightings under my belt, I've never witnessed such distinct pink colors clearly visible and bright to the naked eye. They were almost too bright to photograph properly."
The pink color is probably a sign of nitrogen. Most auroras are green--a verdant glow caused by energetic particles from space hitting oxygen atoms 100 km to 300 km above Earth's surface. Seldom-seen pink appears when the energetic particles descend lower than usual, striking nitrogen molecules at the 100 km level and below. More examples may be found in the realtime photo gallery:
AVIATION RADIATION EXPERIMENT IN PROGRESS: Many people think that only astronauts have to worry about cosmic radiation. Not so. Regular air travelers are exposed to cosmic rays, too. This week, Spaceweather.com and the students of Earth to Sky Calculus are conducting an experiment in aviation radiation. They are flying from North America to Europe and back again to measure dose rates on international flights that cross the Arctic Circle. Here are the data they collected on Oct. 23-24 en route from Portland, Oregon, to Frankfurt, Germany:
Radiation levels in the cabin of the Boeing 767 (Condor flight 2091) tripled within ten minutes after takeoff, and were nearly 40 times ground level by the time the plane reached cruising altitude at 33,000 feet. There was no solar storm in progress. The extra radiation was just a regular drizzle of cosmic rays reaching down to aviation altitudes. This radiation is ever-present and comes from supernovas, black holes, and other sources across the galaxy.
The radiation sensors are the same ones that Earth to Sky Calculus routinely flies onboard helium balloons to measure cosmic rays in the stratosphere. They detect X-rays and gamma-rays in the energy range 10 keV to 20 MeV. These energies span the range of medical X-ray machines and airport security scanners.
This is part of our ongoing program to monitor radiation levels inside airplanes. Stay tuned for results from the return flight on Oct. 27th!
Realtime Space Weather Photo Gallery
Realtime Airglow Photo Gallery