THE STORM IS OVER: Earth's magnetic field is quieting, finally, almost 48 hours after a surprisingly strong geomagnetic storm sparked auroras seen from the Arctic Circle to the continental USA. Arctic sky watchers should nevertheless remain alert for auroras. Earth is passing through a stream of high-speed solar wind, and according to NOAA there is a 40% chance of renewed minor storms on Aug. 28th. Free: Aurora Alerts.
ELECTRICITY FLOWS THROUGH THE SOIL OF NORWAY: When a geomagnetic storm erupts, most eyes naturally turn to the sky, looking for auroras. But during the surprisingly strong G3-class geomagnetic storm of Aug. 26th, there was action underfoot as well. Probes buried in the ground in Norway detected strong currents of electricity moving through the soil. This chart recording made by Rob Stammes at the Polarlightcenter in Lofoten shows wild swings in current during the storm's peak:
"The currents were remarkably strong," says Stammes, who has been monitoring ground currents outside his Arctic observatory for many years. "During the magnetic storm, voltages surged to 10mv/m or 10v/km. That's about 10 times stronger than normal. These are pretty rare readings without a strong solar flare during solar minimum."
Why does electricity flow through the ground during a geomagnetic storm? It's basic physics. Changing magnetic fields cause currents to flow in wires and other conductors. In most places, soil can conduct electricity due to the presence of dissolved salts and minerals. So when the local magnetic field begins to vibrate, electricity naturally begins to flow. Currents induced by geomagnetic storms can cause voltage fluctuations in power systems and in rare cases complete blackouts.
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
All sales support hands-on STEM education
RARE REFLECTION RAINBOW: We've all seen at least one rainbow. Sometimes we even see two. But three? "I have never seen anything like it," says Rune Askeland, who photographed this triple rainbow over of Glesvær, Norway, on August 26th:
"The bird sculptures were created by the artist Kyrre Grepp," explains Askeland. "They are carved from a single large plate of iron and symbolize the mother bird and her children."
The strange rainbow behind those birds is a "reflection rainbow." To understand where it comes from, first remember how normal rainbows form: Sunlight bounces in and out of falling raindrops, which act like tiny prisms, spreading sunbeams into their constituent colors.The two concentric arcs in Askeland's photo are normal rainbows.
Reflection rainbows form in the same way, with one difference: The source of light is not the sun, but rather the reflection of the sun from a nearby body of water. "There are indeed bodies of water nearby--the North Sea and several fjords," says Askeland. Reflected sunlight created the crazy third rainbow, cutting between the other two.