COSMIC RAYS ARE IINCREASING AT AVIATION ALTITUDES: New high-altitude balloon measurements inside the Arctic Circle show that cosmic rays are increasing at aviation altitudes. Commercial flight crews and passengers traveling over Earth's poles now experience as much as 12% more radiation than they did just a few years ago. Check out the data and get the full story right here.
HOW CORONAVIRUS IS AFFECTING STARTRAILS: Something has changed in the night skies of Italy. For years, photographer Paolo Bardelli has enjoyed photographing star trails from his home in Sumirago. "We're only about 15 km from the Milan Malpensa International Airport," he says. "Normally, my images are criss-crossed by many airplanes. When I took this photo on March 11th, however, there were only two."
What happened? "Unfortunately," says Bardelli, "the absence of planes in the sky is the result of the COVID-19 virus, which has forced us into isolation pending an improvement in this bad situation."
One of the world's most popular tourist destinations, Italy is under a strict lockdown in which people are only allowed to leave their homes when it is absolutely necessary. Any Italian who wants to travel has to get permission from authorities. Eerie photos of empty airports are circulating the Internet.
"Here is a comparison image from Jan. 29, 2020," he says. "It shows what the traffic was like before the lockdown began."
The difference is even more striking when you consider that the January image was only 35 minutes long vs. 120 minutes for the March exposure. "We are all staying at home waiting for an improvement in the situation," adds Bardelli, who is still able to walk out in his backyard. "Luckily we have the sky!"
Best wishes from Spaceweather.com to people around the world affected by COVID-19. Hopefully life and skies will soon return to normal.
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NEW ATMOSPHERIC RADIATION MEASUREMENTS: We're back from the Arctic, and we have some new results to share. In January 2020, the students of Earth to Sky Calculus and Spaceweather.com traveled to Abisko, Sweden, to launch a pair of cosmic ray balloons. We'd been there before, launching three identical balloons in March 2017. Putting all the data together, 2017+2020, we find that radiation has increased +12% in the past 3 years:
The graph shows radiation dose rate (uGy/hr) vs. altitude (feet) all the way from ground level to the stratosphere. Radiation appears to be increasing at nearly all altitudes--even in the range 25,000 ft to 40,000 ft where airplanes fly. Polar flight crews and passengers are therefore absorbing ~12% more cosmic radiation than they did only a few years ago.
What's causing the increase? Solar Minimum. At the moment, the sun is near the bottom of the 11-year solar cycle. During Solar Minimum, the sun's magnetic field weakens, allowing extra cosmic rays from deep space to penetrate the solar system. These cosmic rays are hitting Earth's atmosphere, creating a spray of secondary cosmic rays that shower toward the ground below.
Secondary cosmic rays are what we measure. Radiation sensors onboard our helium balloons detect X-rays and gamma-rays in the energy range 10 keV to 20 MeV, similar to what you get from medical X-ray machines and airport security scanners.
Above: Schematic diagram of a cosmic ray air shower. Learn more from CERN.
We've been launching radiation sensors almost weekly for 5 years--mainly from California, the "home base" of Spaceweather.com. Cosmic rays in the stratosphere have been increasing the entire time, a sign of deepening Solar Minimum.
The new data from Abisko, Sweden, show the increase is not limited to the stratosphere. It is also happening at aviation altitudes with a 3-year increase of ~12% even below 40,000 ft. We're planning another ballooning trip to Sweden in August 2020 to confirm these results. Stay tuned.
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MR. SPOCK BOBBLEHEAD IN THE STRATOSPHERE: If you would like to support the Earth to Sky Calculus cosmic ray ballooning program, there's a logical way to do it. Puchase this Mr. Spock collector's item. Here is the green-blooded science officer floating 32.2 km (112,200 ft) above Death Valley National Park in central California:
You can have him for $170.10. The price, in case you're wondering, is the serial number of the Enterprise, NGC1701, divided by 10. The students are selling Spock to buy more helium! He comes with a greeting card showing the high-quality resin bobblehead in flight and telling the story of his journey to the stratosphere and back again.
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FRIDAY THE 13TH AURORAS: Friday the 13th was a lucky day for some Arctic sky watchers. A solar wind stream almost missed Earth, but didn't. Gaseous material flowing from a southern hole in the sun's atmosphere grazed our planet's magnetic field, sparkingauroras over Alaska, Canada and Finland. No more solar wind streams are due to arrive for at least a week. Aurora alerts: SMS Text.
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