Satellite Mix-Up: How a Dead NASA Craft Tricked Astronomers

Astronomers had a surprise when they thought they found a powerful radio burst from deep space. It turned out to be a signal from an old, broken NASA satellite called Relay 2. This satellite has been floating in space since 1964 and stopped working in 1967. The signal was so strong that it blocked out other signals from the sky. It lasted less than 30 nanoseconds, which is much shorter than most fast radio bursts (FRBs). FRBs are mysterious signals from far away in the universe. They are usually from other galaxies and last from microseconds to milliseconds. But this signal was different. It was very bright but came from a satellite just 2, 800 miles away. This made it seem brighter than it really was. The team used the Australian Square Kilometer Array Pathfinder (ASKAP) telescope to find the signal. They thought it was from space, but it was actually from the old satellite. The team was not disappointed. They saw it as a puzzle to solve. They had to adjust their measurements because the signal was so close. This discovery shows that radio telescopes can also be used to monitor satellites. The team thinks the signal might have been caused by a spark or a tiny space rock hitting the satellite. But they are not sure. The team is sure that other FRBs are not from satellites. Most telescopes can pinpoint where FRBs come from and can tell if they are from space or not. The signal from Relay 2 had almost no delay, which means it came from close by. This is very different from real FRBs, which have a big delay because they come from so far away. This discovery shows that we need to be careful not to mix up signals from space with signals from satellites. It also shows that radio telescopes can be used to monitor satellites and help prevent damage. The team hopes to find more of these signals and learn more about them.