Measuring Earth’s precise position, a crucial task for modern technology, is being hampered by an increasingly crowded radio spectrum.
Cosmic signals vital for navigation are drowned out by everyday tech.
Our ability to know exactly where we are on Earth, a process called geodesy, relies on tracking radiation from incredibly distant black holes.
- Geodesy uses signals from distant black holes for precise Earth positioning.
- Radio waves used for black hole tracking are also used by Wi-Fi and mobile phones.
- Increasing human-made radio pollution is blocking these essential signals.
- This interference risks many satellite services, impacting daily life.
- International cooperation and spectrum allocation are needed to solve the problem.
These cosmic signals “pass cleanly through the atmosphere and we can receive them during day and night and in all weather conditions,” according to a senior scientist at the University of Tasmania. However, the very radio waves that carry these vital signals are also used for communication on Earth, including Wi-Fi and mobile phones.
While a few narrow “lanes” are reserved for radio astronomy, the radio highway has seen a massive increase in traffic in recent decades. Scientists previously could “stray” from these astronomy lanes to capture the faint black hole signals. But to achieve the high precision modern technology demands, geodesy now requires more than just the exclusively reserved astronomy lanes.
The surge in human-made electromagnetic pollution is a growing concern. When Wi-Fi and mobile phone services emerged, scientists adapted by moving to higher frequencies. Yet, they are now running out of available spectrum. With six generations of mobile phone services, each occupying a new lane, crowding the airwaves, the multitude of signals are often too strong for geodetic observatories. These powerful signals can easily overpower the very weak signals emitted by black holes, jeopardizing many satellite services we rely on.
To ensure these critical services continue functioning, geodesy needs more space on the radio highway. This means geodesists must have a voice at international world radio conferences where spectrum is divided. Potential solutions also include establishing “radio quiet zones” around essential radio telescopes and working with satellite providers to prevent their emissions from directly targeting these observatories. However, any solution must be global, as linking radio telescopes worldwide is how we achieve measurements with the precision of a telescope as large as Earth.
The primary challenge lies in the fact that the radio spectrum is largely regulated by individual nations. Increasing public awareness is a vital first step. If we want satellite navigation to function, our supermarkets to remain stocked, and online financial transactions to arrive safely, we must ensure a clear view of those distant black holes. That starts with clearing the radio highway.
