Since January 21, 2025, the Alaskan sky has become an open-air laboratory. From Poker Flat Research Range Fairbanks, NASA launched two rockets through the Northern Lights to study an enigmatic phenomenon: the black auroras, dark zones that interrupt the vortices of light. Led by physicists Marilia Samara e Robert Michell, the missions aim to capture data on the electrons responsible for these luminous “absences”.
“It's not a witch hunt, but a plasma physics hunt,” jokes Michell. in a NASA press release. The 18-meter-tall rockets reach 130 km altitude in 5 minutes, flying through active auroras. The trick? Ground-based cameras at locations Fairbanks e Venice (209 km further north) track the movement of the lights, calculating the exact moment for the launch.
GIRAFF and Black Holes: Two Experiments, One Mystery
The first mission, GIRAFF (Ground Imaging to Rocket investigation of Auroral Fast Features), compare pulsating auroras (3 flashes per second) and flickering (15 flashes). The rocket measures the energy and arrival times of the electrons, trying to understand why some accelerate faster.
The second of two missions, instead, goes straight to the black auroras. “We suspect that the electrons are reversing direction, creating gaps,” Samara explains. The rocket carries sensors to detect these “rogue” particles that, instead of emitting light, steal it.
A crucial detail: these dynamics influence the geomagnetic storms, capable of disrupting satellites and electrical grids.
The Timing Puzzle: Why Firing a Rocket Is Like Catching Lightning
Launching a spacecraft into an aurora is an exercise in humility. The window is open from the 21st, but timing is needed. “You have to predict where the phenomenon will be in five minutes, the time it takes for the rocket to reach the right altitude,” explains Michell. Cameras on the ground help, but a bit of luck is also needed. What if the auroras move? “We have a launch window of weeks,” Samara reassures.
Meanwhile, the data collected could rewrite the space physics manuals. Because, as NASA recalls, every aurora is a natural experiment: Solar particles interact with the Earth's atmosphere in ever-changing ways, creating a spectacle that is also a scientific goldmine.
Why is it important to study dark auroras? From the sky to our pockets
The study of dark auroras is important for two reasons:
- Protecting technologyThe charged particles that create auroras can fry satellite circuits and “shut down” electrical grids (as in the 1989 Quebec blackout).
- Understanding the EarthAuroras are windows into the interactions between Earth's magnetic field and the solar wind.
While waiting to process the data, researchers are already clear on one thing: the black auroras are not a manufacturing defect in the sky, but a clue. Perhaps, among those "tears" in the sky lies the key to predicting (and mitigating) future space storms.