Our solar system's second known interstellar visitor appears to be keeping quiet, just like the first.
The Breakthrough Listen SETI (search for extraterrestrial intelligence) project has scanned the interstellar Comet Borisov for "technosignatures" but come up empty so far, scientists announced today (Feb. 14).
Breakthrough Listen also encountered radio silence during an earlier investigation of the mysterious 'Oumuamua, the first confirmed interstellar object ever spotted in our solar system. The null results may be disappointing to alien enthusiasts out there, but they're valuable all the same, project team members said.