Aliens might live on a planet without a large moon but it’s pretty unlikely for their planet to be the only object in orbit around their star. The easy way to m

Aliens might live on a planet without a large moon but it’s pretty unlikely for their planet to be the only object in orbit around their star. The easy way to measure the Earth-Sun distance today is to use radar to precisely measure our distance from Venus and triangulate our position from that. Aliens with radar could do the same trick using other objects in their home planetary system. But even before radar, we had parallax methods for figuring this stuff out. Radar just brings the error down into the low parts-per-billion territory.