La NASA ha lanciato una missione per testare una navicella spaziale in grado di distruggere eventuali asteroidi minacciosi per la Terra: il DART (Double Asteroid Redirection Test) è un vero e proprio esperimento partito alle 22:21 di oggi (mercoledì) ora del Pacifico (le 7.21 in Svizzera) a bordo di un razzo SpaceX dalla Vandenberg Space Force Base in California.
L'obiettivo è alterare leggermente la traiettoria di Dimorphos, una "luna" larga circa 160 metri che circonda un asteroide molto più grande chiamato Didymos. I due orbitano insieme intorno al Sole.
L'impatto dovrebbe avvenire nell'autunno del 2022, quando il sistema di asteroidi si troverà a 11 milioni di chilometri dalla Terra, il punto più vicino mai raggiunto.
"Stiamo cercando di imparare come deviare una minaccia", ha detto Thomas Zuburchen, capo del progetto da 330 milioni di dollari, il primo del suo genere.
Gli asteroidi in questione non rappresentano una minaccia reale per il nostro pianeta ma appartengono a una classe di corpi celesti noti come Near-Earth Objects (NEO), che possono avvicinarsi alla Terra entro i 30 milioni di miglia. Ci sono 10.000 asteroidi vicini alla Terra conosciuti di dimensioni pari o superiori a 140 metri, ma nessuno ha una possibilità significativa di colpire il pianeta nei prossimi 100 anni. Gli scienziati pensano che vi siano ancora altri 15.000 oggetti simili in attesa di essere scoperti.
Da Setteventi del 24.11.2021
RSI Info 24.11.2021, 09:33
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