After an expedition that spent about 10 days scouring the ocean floor off Papua New Guinea with a magnetic sled, Harvard University astrophysicist Avi Loeb says he has collected more than 700 metallic spherules that are now undergoing detailed examination in his lab at Harvard as well as at least two other independent labs that he asked to help out.
Loeb believes that many of these spherules, each less than a millimeter across (about the size of a pinhead), came from the first-ever interstellar meteorite to have been detected striking the Earth. He was able to pinpoint its entry location in the South Pacific through a combination of Department of Defense tracking data and seismic readings from two nearby locations.
“It’s the most exciting week of my scientific career,” Loeb told Astronomy in a shipboard Zoom interview during the expedition. In a followup interview after his return to Cambridge, he said the number of spherules identified in the collected material has continued to rise day by day.
Loeb says he expects to have collected enough data on these materials to be able to submit a formal paper to a peer-reviewed journal “hopefully within a month.” If the composition of these spherules differs in significant ways from that of any known solar system object or terrestrial contamination, it would go a long way toward convincing other scientists that the material is indeed from an interstellar object. That would make it only the third such object ever accepted as having been discovered – and the first one to be recovered on Earth. The interstellar asteroid ‘Oumuamua was the first, and Comet Borisov was the second. [Continue reading…]