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Una nube di satelliti artificiali, molto simile a quella che ormai circonda la Terra, potrebbe essere la firma tecnologica di una civiltà extraterrestre e, se oggi è ancora difficile intercettarla, in un futuro non lontano potrebbe essere alla portata dei telescopi di nuova generazione.
A ispirare l’idea, pubblicata sull'Astrophysical Journal, è in particolare un articolo del 1945 nel quale Arthur C. Clarke, uno dei più grandi scrittori di fantascienza di tutti i tempi proponeva di inviare satelliti artificiali in orbita geostazionaria intorno alla Terra per creare una rete globale per le comunicazioni.
In suo onore la regione a circa 36'000 chilometri sopra il nostro pianeta, che ora ospita circa 400 satelliti, è stata chiamata Fascia di Clarke. Al momento ospita solo un terzo dei satelliti in orbita intorno alla Terra: la maggior parte si trova molto più in basso, a circa 2'000 chilometri dalla superficie. Questo vuol dire che la nostra fascia non è ancora rilevabile da ipotetici alieni, ma potrebbe diventarlo entro il 2200.
ATS/Bleff
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