SETI: Search for interplanetary radio signals now also possible
The search for signals from extraterrestrial civilizations has been limited to the strongest ones. Now we could find ones that are not meant for us.
The Allen Telescope Array is the first radio telescope designed directly for the search for extraterrestrials
(Image: SETI Institute)
A group of researchers has succeeded for the first time in searching for radio signals in another star system that are transmitted between the planets there and are intended for probes there, for example. This is reported by Pennsylvania State University and explains that they could use it to search elsewhere for exactly the kind of signals that humanity itself emits. In this specific case, the team did not find what they were looking for in the TRAPPIST-1 star system with its seven exoplanets, but the technology is very promising for further searches in conjunction with more powerful observatories.
Searching for signals not intended for us
As head of research Nick Trusay recalls, most searches for signals from extraterrestrial civilizations assume that only those sent specifically to other stars can be found –, i.e. a kind of beacon. But our technology is now so good that we can search for signals from comparatively nearby stars that are not intended for us or anyone else, but are sent to probes conducting research there. And even more powerful observatories are already being built.
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In principle, the approach now described in a research article can be used to detect signals such as those emitted by humanity itself. In the TRAPPIST-1 system, 41 light years away, the research team used it to search for signals when several of the planets there were in succession from our perspective. The team is convinced that it might have been possible to detect signals sent between them. However, now that nothing has been found with the Allen Telescope Array (ATA), the technology is to be further improved and other star systems targeted.
TRAPPIST-1 is currently one of the most interesting stars when it comes to the search for extraterrestrial life. So far, seven rocky planets have been discovered around the red dwarf star TRAPPIST-1, on which even liquid water appears to be possible. In the case of two planets that orbit too close to the star for this, hopes of at least an extremely dense atmosphere like that of Venus have recently been dashed. Nevertheless, the star and its planets remain the focus of research, and the ultimately unsuccessful search for radio signals is unlikely to change this.
(mho)
