NASA’s Cassini spacecraft collected obscure trickles of dust from the outer reaches of our solar system. A coalition of scientists mostly from Europe spearheaded the research. The original account was published in this week’s edition of the journal Science.
Cassini has been orbiting Saturn since 2004 analyzing the planet, its rings, and moons. But the vessel has also sampled millions of ice-rich dust particles of which, originate from the surface of Saturn’s geologically active moon Enceladus. Yet a few gathered specs from the millions—36 dust samples—are believed to have originated from interstellar space, the void between the stars.
Viewed as a sort of alien dust, the gathered samples have been anticipated from the 1990’s when the ESA/NASA Ulysses mission made initial observations followed by NASA’s Galileo spacecraft.
Nicolas Altobelli, Cassini project scientist at ESA (European Space Agency) and lead author of the study, said, “From that discovery, we always hoped we would be able to detect these interstellar interlopers at Saturn with Cassini. We knew that if we looked in the right direction, we should find them.” And “Indeed, on average, we have captured a few of these dust grains per year, travelling at high speed and on a specific path quite different from that of the usual icy grains we collect around Saturn.”
Cassini, as opposed to Ulysses and Galileo, was able to break down the composition of the dust formed of various materials. All had a geological composition of magnesium, silicon, iron, and calcium but more reactive elements such as sulfur and carbon were absent.
“Cosmic dust is produced when stars die, but with the vast range of types of stars in the universe, we naturally expected to encounter a huge range of dust types over the long period of our study,” said Frank Postberg of the University of Heidelberg, a co-author of the research and partner investigator of Cassini’s dust analyzer. The report was published in Phys.org.