ARCTIC AURORAS POSSIBLE TONIGHT: An irregular hole in the sun's atmosphere is spewing a stream of solar wind toward Earth. Estimated time of arrival: Oct. 24th. High-latitude sky watchers should be alert for auroras when the gaseous material arrives. A bright full Moon on Oct. 24th will add its luminosity to that of any geomagnetic storm, creating some nice landscape photo-ops around the Arctic Circle. Free: Aurora Alerts.
ATMOSPHERIC COSMIC RAYS ARE INCREASING: So you thought Solar Minimum was boring? Think again. High-altitude balloon flights conducted by Spaceweather.com and Earth to Sky Calculus show that atmospheric radiation is intensifying from coast to coast over the USA--an ironic result of low solar activity. Take a look at the data:
Above: Dose rates at the Regener-Pfotzer Maximum, ~65,000 ft high at the entrance to the stratosphere.
Since 2015, we have been monitoring X-rays, gamma-rays and neutrons in the stratosphere--mainly over central California, but also in a dozen other states (NV, OR, WA, ID, WY, KS, NE, MO, IL, ME, NH, VT). Everywhere we have been there is an upward trend in radiation--ranging from +20% in central California to +33% in Maine. The latest points, circled in red, were gathered during a ballooning campaign in August-October 2018.
How does Solar Minimum boost radiation? The answer lies in the yin-yang relationship between cosmic rays and solar activity. Cosmic rays are the subatomic debris of exploding stars and other violent events. They come at us from all directions, 24/7. Normally, the sun's magnetic field and solar wind hold cosmic rays at bay--but during Solar Minimum these defenses weaken. Deep-space radiation surges into the solar system.
Cosmic rays crashing into our planet's atmosphere produce a spray of secondary particles and photons. That secondary spray is what we measure. Each balloon flight, which typically reaches an altitude greater than 100,00o feet, gives us a complete profile of radiation from ground level to the stratosphere. Our sensors sample energies between 10 keV and 20 MeV, spanning the range of medical X-ray machines, airport security devices, and "killer electrons" in Earth's radiation belts.
Who cares? For starters, anyone who flies. Cosmic radiation at aviation altitudes is typically 50 times that of natural sources at sea level. Pilots are classified as occupational radiation workers by the International Commission on Radiological Protection (ICRP) and, according to a recent study from researchers at the Harvard School of Public Health, flight attendants face an elevated risk of cancer compared to members of the general population. They listed cosmic rays as one of several risk factors. Weather and climate may also be affected, with some research linking cosmic rays to to the formation of clouds and lightning. Finally, there are studies (one recently published in Nature) asserting that heart rate variability and cardiac arrhythmias are affected by cosmic rays in some populations. If true, it means the effects reach all the way to the ground.
As 2018 comes to an end, Solar Minimum appears to be just getting started. Cosmic rays could continue to increase for years to come, so stay tuned. A sharable version of this story is available here.
Realtime Space Weather Photo Gallery
DECLARE YOUR SUPPORT FOR PLUTO: Pluto is a planet. It's obvious, right? Pluto has a large moon, a nitrogen atmosphere, towering mountains, deep canyons, and a geologically active surface. Declare your support for the 9th planet with a "Pluto is a Planet" Space Pendant:
You can have one for $79.95. The students of Earth to Sky Calculus are selling these pendants to support their cosmic ray ballooning program. Each one comes with a greeting card showing the item in flight onboard a balloon, and telling the story of its journey to the edge of space and back.
They make a great gift for rebellious astronomers! All sales support the Earth to Sky Calculus cosmic ray ballooning program and hands-on STEM research.
Far Out Gifts: Earth to Sky Store
All sales support hands-on STEM education