“An artificial submoon may be stable and thereby serve as a time capsule or outpost for a technological civilization. On a stable orbit around the Moon–such as the one for NASA’s proposed Lunar Gateway–a submoon would keep humanity’s treasures safe for posterity long after Earth became unsuitable for life.”
Astronomers believe they have discovered the first known moon beyond our solar system, in orbit around a gigantic planet 8,000 light years away. “The first exomoon is obviously an extraordinary claim and it requires extraordinary evidence,” said David Kipping, an astronomer at Columbia University in New York who has spent more than a decade hunting for far-flung moons. The moon’s Neptune size was on a scale that had “hardly been anticipated” and “defies easy explanation” based on current theories of moon formation.
