SOLAR WIND TO GRAZE EARTH: Minor geomagnetic unrest is possible on May 23rd when a stream of solar wind is expected to graze Earth's magnetic field. The gaseous material is flowing from a northern hole in the sun's atmosphere. High-latitude sky watchers should be alert for auroras, especially in the southern hemisphere where deepening autumn darkness favors visibility of Southern Lights. Free: Aurora Alerts.
ATMOSPHERIC RADIATION UPDATE: Cosmic rays over California continue to intensify, according to high-altitude balloons launched by Spaceweather.com and the students of Earth to Sky Calculus. We've been monitoring secondary cosmic rays in the stratosphere with regular launches from Bishop CA since 2015. In the data plot below, 3 of the 4 highest measurements have occurred just in the past few months:
The worsening cosmic ray situation is linked to the solar cycle. Right now, the sun is heading toward a deep Solar Minimum. As the outward pressure of solar wind decreases, cosmic rays from deep space are able to penetrate the inner solar system with increasing ease. This same phenomenon is happening not only above California, but all over the world.
Take another look at the data plot. The general trend in radiation is increasing, but it is not perfectly linear. From launch to launch we see significant up and down fluctuations. These fluctuations are not measurement errors. Instead, they are caused by natural variations in the pressure and magnetization of the solar wind.
The sensors we send to the stratosphere measure X-rays and gamma-rays, which are produced by the crash of primary cosmic rays into Earth's atmosphere. The energy range of the sensors, 10 keV to 20 MeV, is similar to that of medical X-ray machines and airport security scanners. Stay tuned for updates as the monitoring program continues.
A BASEBALL IN THE STRATOSPHERE: Some home runs begin with the loud crack of a bat. This one began with a countdown: "10, 9, 8, 7...." On May 17, 2018, the students of Earth to Sky Calculus launched this Giants ball to the stratosphere on a cosmic ray balloon:
Riding alongside an array of radiation sensors, which the students use for atmospheric research, the commemorative baseball sailed 34.2 km (112,205 feet) above Earth's surface. Now that's a home run!
The students are selling these balls as a fundraiser. You can have one for $129.95. Each baseball comes with a greeting card showing the ball in flight and telling the story of its journey to the stratosphere. They make great Father's Day gifts.
Are you a fan of a different team? We also have "space balls" for the Angels, Red Sox, Dodgers, and Padres. Coming soon: Royals, Cubs, Yankees, Astros. If your home team is not on the list, let us know and we will fly it for you on an upcoming flight.
Far Out Gifts: Earth to Sky Store
All proceeds support hands-on STEM education
IRON-EATING BACTERIA SHOW THEIR COLORS: Ed Kreminski of Ohio is an avid sky watcher, often photographing icy iridescent clouds drifting overhead. On May 12th, he noticed a completely different kind of iridescence--at his feet. "While crossing a hiking bridge along the sandstone cliffs of the Hocking Hills State Park, I came across this colorful scene along the creek's edge," he says. Iron-eating bacteria made the rocks even more colorful than than the sky:
"The rainbow sheen on the rocky shore is caused by a thin film of bacteria that lives off the iron leaching out of the rocks," says Kreminski.
How to bacteria create iridescent rocks? Simple. They coat the rocky surface in a thin layer or film. Light waves reflected by the upper and lower boundaries of a thin film interfere with one another, producing bands of color. The effect is most familiar in soap bubbles and oil slicks, but bacteria can do it too.
"I wonder, will such bacteria ever be found on Mars?" says Kreminski. The Red Planet certainly has plenty of iron. All the more reason to repair Curiosity's busted jackhammer.