Context:

A powerful radio signal detected by Australia's ASKAP telescope in June was traced to the long-defunct NASA satellite, Relay 2, which ceased functioning in 1967. Initially mistaken for a potential astronomical phenomenon, the signal puzzled astronomers due to its proximity to Earth. The source was identified as a buildup of static electricity on the satellite, causing a massive spark, although a micrometeorite impact was also considered. This event highlights the challenges posed by space debris and the possibility of confusing satellite signals with genuine astrophysical phenomena. The study emphasizes the importance of developing methods to distinguish between man-made and natural radio bursts as the number of satellites in orbit increases.

Dive Deeper:

• The ASKAP radio telescope in Western Australia detected a strong radio signal in mid-June from the NASA satellite Relay 2, which has been inactive since 1967. Researchers initially thought this signal might be a new astronomical object due to its brightness.

• Upon further investigation, the signal was found to originate only 4,500 kilometers from Earth, eliminating the possibility of it being a distant galactic object. The source was confirmed to be the defunct Relay 2 satellite, an experimental communications satellite launched in 1964.

• The likely cause of the signal was a sudden release of static electricity accumulated on the satellite's metal surface, a common yet usually harmless phenomenon for spacecraft. This event caused the signal to become the brightest in the sky, outshining other radio data by a factor of thousands.

• Researchers considered the alternative possibility of a micrometeorite impact causing the signal, but this scenario was deemed less likely due to the strict conditions required for such an event to occur.

• The discovery underscores the growing issue of space debris and its potential interference with astronomical observations. As more satellites are launched, distinguishing between artificial and natural radio signals becomes increasingly critical.

• Scientists are encouraged to develop cost-effective and efficient tools to monitor these electrostatic discharges from Earth, which could provide insights into satellite behavior and prevent misinterpretation in future galactic studies.

• The study serves as a reminder of the complexities involved in space exploration and observation, where man-made objects can sometimes mimic or obscure natural cosmic phenomena.