NASA's surprising discovery: Mysterious shapes in Earth's ionosphere

NASA scientists have discovered mysterious shapes in the upper layer of the atmosphere. According to researchers, the C and X-shaped formations indicate that we still have much to learn about the ionosphere and its impact on communication and navigation signals passing through it.

Similar shapes had been observed before, but this time, they appeared in unexpected locations and at surprising moments. The NASA Observations of the Limb and Disk (GOLD) mission facilitated a more detailed observation of these C and X-shaped formations. The mission's primary goal is to measure density and temperature in our planet's thermosphere and ionosphere.

NASA reminds us that the ionosphere, which stretches from 31 to 373 miles above our heads, becomes electrically charged during the day when sunlight hits the Earth, causing its energy to knock electrons out of atoms and molecules. This creates a mixture of charged particles, called plasma, which allows radio signals to be transmitted over long distances. Plasma is also influenced by the Earth's magnetic field, which creates these shapes.

"Near Earth's magnetic equator, charged particles are funneled upward and outward along magnetic field lines, creating two dense bands of particles north and south of the equator that scientists call crests. As night falls and the Sun's energy fades, low-density pockets in the plasma, called bubbles, can form in the ionosphere. Because of their varying density, the crests and bubbles can interfere with radio and GPS signals," NASA explains in a press release.

The latest research has shown that different plasma shapes in the ionosphere can form not only after solar storms and significant volcanic eruptions but also during so-called “quiet times.” This suggests that local factors play a more significant role in these processes. Additionally, computer models indicate that conditions in the lower atmosphere likely cause the plasma to move downward.

"Forming an X-shaped pattern (EIA‐X)—has been observed around the magnetic equator during geomagnetic quiet conditions," said Fazlul Laskar, an ionospheric physicist from the University of Colorado. He added that this was an unexpected phenomenon in calm geomagnetic conditions.

Scientists were also surprised by the appearance of plasma shaped like the letter C and its inverse. These formations, likely created by winds on Earth, appeared close to each other—at a distance of about 394 miles. Observing such shapes is rare—they have only been noticed twice. Therefore, scientists on the GOLD mission plan further studies to understand exactly what causes their formation. "Within that close proximity, these two opposite-shaped plasma bubbles had never been thought of, never been imaged," noted Deepak Karan, an ionospheric physicist from the University of Colorado.

The plasma in the ionosphere is crucial for long-distance radio wave transmission, and the latest discoveries help us better understand how radio and GPS systems work. This is especially true since disturbances in the ionosphere, such as those observed, can affect communication and navigation infrastructure.