Planetary electromagnetic waves, such as radio waves and other forms of electromagnetic radiation emitted by planets, are generally not suitable for interstellar communications. There are a few reasons for this:
Limited range: Planetary electromagnetic waves tend to be relatively weak and quickly attenuate as they propagate through space. By the time they reach interstellar distances, they are typically too faint to be detected and deciphered by potential recipients.
Directionality: Planetary electromagnetic waves are usually emitted in various directions from the planet's surface. They are not specifically directed towards interstellar targets, making it highly improbable for any extraterrestrial civilization to intercept and understand them as intentional communication signals.
Background noise: Space is filled with a myriad of natural and artificial sources of electromagnetic radiation, which can create significant background noise. This noise can interfere with the detection and decoding of weak planetary electromagnetic waves, further reducing the likelihood of successful interstellar communication.
For interstellar communication, dedicated efforts are required to send intentional and directed signals towards specific targets. Various methods have been proposed for interstellar communication, including powerful radio signals or laser-based communication systems. These methods aim to overcome the challenges associated with long distances, background noise, and the need for highly focused and targeted signals.
It's worth mentioning that the search for extraterrestrial intelligence (SETI) actively scans the sky for potential signals from other civilizations. However, these efforts focus on detecting intentional and directed signals rather than relying on planetary electromagnetic waves as a primary means of communication.