Astronauts Capture Transient Luminous Events Above Storms

Astronauts aboard the International Space Station (ISS) have been documenting unusual electrical phenomena known as transient luminous events (TLEs), which occur above thunderstorms. These brief flashes of light, including red sprites, blue jets, and gigantic jets, can reach altitudes of up to 89 kilometers (about 55 miles) and are difficult to observe from the ground due to cloud cover. TLEs are significant as they can disrupt communication systems and pose risks to aircraft and spacecraft, affecting the upper atmosphere where radio waves travel.

Astronauts photograph from the ISS a red electrical phenomenon exploding above storms at altitudes of up to 89 kilometers (about 55 miles)—a phenomenon that for decades seemed nothing more than a pilo

One notable observation occurred on July 3, 2025, when astronaut Nichole Ayers photographed a gigantic jet, a type of TLE that acts as an electrical bridge between storm tops and the upper atmosphere. This event was initially misidentified as a sprite, highlighting the challenges in distinguishing between different types of TLEs. The Atmosphere-Space Interactions Monitor (ASIM), a tool mounted on the ISS since April 2018, has been instrumental in capturing these phenomena, allowing researchers to correlate observations from space with lightning activity below.

Astronauts photograph from the ISS a red electrical phenomenon exploding above storms at altitudes of up to 89 kilometers (about 55 miles)—a phenomenon that for decades seemed nothing more than a pilo

Another experiment, the Thor-Davis project, utilizes a high-speed camera capable of capturing 100,000 images per second to study lightning events in detail. This technology has recorded red sprites at altitudes of 25 to 50 miles, providing valuable data for understanding the dynamics of electrical storms.

Astronauts photograph from the ISS a red electrical phenomenon exploding above storms at altitudes of up to 89 kilometers (about 55 miles)—a phenomenon that for decades seemed nothing more than a pilo

The implications of TLEs extend beyond mere curiosity. They can affect long-distance radio communications and aircraft operations, making the study of these phenomena crucial for safety and reliability in aviation. Additionally, researchers are investigating the potential climate impacts of TLEs. A report from the Institute of Astrophysics of Andalusia suggests that certain electrical discharges in clouds may trigger chemical reactions that produce greenhouse gases like nitrous oxide and ozone, which contribute to atmospheric heating.

Astronauts photograph from the ISS a red electrical phenomenon exploding above storms at altitudes of up to 89 kilometers (about 55 miles)—a phenomenon that for decades seemed nothing more than a pilo

NASA has emphasized the importance of the data collected from TLE observations, stating that each new pass over a storm enhances our understanding of how Earth's weather interacts with the upper atmosphere. The agency's ongoing research aims to clarify the risks associated with TLEs, particularly regarding their effects on aircraft.

Astronauts photograph from the ISS a red electrical phenomenon exploding above storms at altitudes of up to 89 kilometers (about 55 miles)—a phenomenon that for decades seemed nothing more than a pilo

While the research on TLEs is advancing, some experts express concerns about the unknowns surrounding the frequency and impact of terrestrial gamma-ray flashes, which are high-energy bursts associated with storms. A 2009 report from the University of Florida indicated that a close encounter with such radiation could deliver a dose comparable to 400 chest X-rays, although the actual risk to aircraft remains uncertain.

Astronauts photograph from the ISS a red electrical phenomenon exploding above storms at altitudes of up to 89 kilometers (about 55 miles)—a phenomenon that for decades seemed nothing more than a pilo

• “The Davis camera works well and gives us the high temporal resolution necessary to capture the quick processes in the lightning,” — Olivier Chanrion, Researcher

Astronauts photograph from the ISS a red electrical phenomenon exploding above storms at altitudes of up to 89 kilometers (about 55 miles)—a phenomenon that for decades seemed nothing more than a pilo

As research continues, the ISS is transforming the understanding of TLEs from a rare curiosity into a growing dataset, revealing the complex interactions between storms and the upper atmosphere.

Astronauts photograph from the ISS a red electrical phenomenon exploding above storms at altitudes of up to 89 kilometers (about 55 miles)—a phenomenon that for decades seemed nothing more than a pilo