Well we left a mirror on the moon,and it reflects a blue light back to
Earth(are best proof we were there) Why not have a rover with a laser
pulsing an intense laser beam back to Earth A gas laser produces a
continual beam of light,and maybe that is better. We use lasers now for
very accurate distance measuring. Seems a laser was a man
made invention (nature does not use a laser) Someday we will use lasers
to tell other intelligent civilizations in our galaxy that we are here.
Bert