Space Anomaly Traced to 60-Year-Old Satellite

Astronomers were recently baffled by an ultra-brief burst of radio waves detected from somewhere in space. Surprisingly, after thorough investigation, the source was pinpointed not billions of light-years away, but a mere 4,500 kilometers from Earth: a defunct satellite from the early 1960s.

Unusual Radio Signal

Researchers, employing the Murchison Radio-astronomy Observatory in Western Australia, first observed the strange radio signals. They were using the Australian Square Kilometre Array Pathfinder (ASKAP) radio telescope, seeking elusive fast radio bursts. The team was shocked to find that the source was incredibly close, within our own galaxy.

The detected signal showed no dispersion, a sign that it originated nearby. The origin of fast radio bursts has long puzzled scientists. Some speculate they emanate from magnetars, while others suggest cosmic collisions may be the source.

The burst was incredibly short, lasting just billionths of a second. This extreme brevity distinguished it from typical radio interference, or human-made signals. Initially, the team considered that this burst could be from interference, but the signal’s speed ruled that out.

Unexpected Source Identified

After ruling out astronomical signals, the team investigated the direction from which the burst originated. The blurriness of the image helped determine the distance. The only object at that location, at that time, was Relay 2, a satellite launched in 1964 by the United States.

Relay 2, one of the first telecommunications satellites, ceased operations in 1965. Its systems had failed by 1967. How could this aged spacecraft emit such a rapid burst of radio waves?

Possible Explanations

One theory involves electrostatic discharge. Satellites can accumulate electrical charges from space’s charged gases, leading to a sudden discharge. Though common, these usually last thousands of times longer than the observed signal. A micrometeoroid strike is another possibility, which is also less likely.

The signal’s brevity makes a definitive explanation elusive. The team did find new astronomical signals, so more research is warranted.

According to NASA, there are currently over 6,700 satellites orbiting Earth, a number that is constantly growing (NASA 2023).

The Future of Space Monitoring

The signal was undetectable over longer timescales, highlighting the need for monitoring on the nanosecond level. The findings demonstrate the feasibility of monitoring satellites for electrostatic discharges. As the number of satellites increases, identifying new monitoring methods is vital.