A decade-old European satellite has given Italian scientists a detailed look into a dangerous radiation zone located a few hundred kilometers above the coast of Brazil.
Known as the South Atlantic Anomaly (SAA), or “Bermuda Triangle of Space,” the region has reportedly caused satellites and telescopes to malfunction and temporarily affected astronauts’ eyesight.
According to scientists, the SAA is the point where the Van Allen radiation belts—rings of charged particles that sit roughly 1,000 to 6,000 kilometers above the surface of Earth—are closest to the planet’s surface. When the belts were first discovered in the 1950s, scientists suspected the SAA could pose an eventual threat.
Now, as spacecraft electronics continue to become more complex, the problems caused by the SAA have also increased. Astronauts have reported their laptop computers would occasionally crash when they passed through the region, in addition to seeing strange “shooting stars” flash in front of their eyes. Some mitigation measured have been developed: certain spacecraft such as the Hubble Space Telescope are programmed to switch off their sensitive instruments as they fly through the SAA to avoid damage, while the International Space Station is constructed with extra shielding for protection. As scientists continue to explore space using more sophisticated instruments, however, more detailed knowledge of the SAA is needed.
A team of researchers led by Riccardo Campana at the National Institute for Astrophysics in Bologna, Italy have developed a way to better calculate the changing boundaries of the SAA using data recorded by BeppoSAX, a Italian–Dutch satellite active from 1996 to 2003 that was used to study gamma-ray bursts. Most notably, the researchers discovered that the radiation levels in the lower layer of the SAA were much less than in the upper layers, and that the anomaly was slowly drifting westward at a rate of about 40 kilometers per year.
Campana and his colleagues are currently designing a space telescope that will orbit through the lower part of the danger zone in an effort to further understand the area, which is currently not well-studied. The new telescope will follow a similar orbit to BeppoSAX.
“Most radiation models used in planning space missions are based on extrapolations from high-latitude, high-inclination observations,” says Campana, making them less accurate for different types of orbits. Data from the new space telescope is expected to assist scientists in better preparing future space missions.
