• XeroxCool@lemmy.world
        link
        fedilink
        English
        arrow-up
        23
        ·
        edit-2
        9 months ago

        Fun fact: the average laser’s collimation expands to the size of a football field by time it reaches the altitude of the ISS. The moon is 1,000x further. Despite the higher refinement of the laser used to bounce light off the retro reflector, it still takes an incredibly strong sensor to detect the bounce back. It’s not how The Big Bang Theory portrays it.

        Now that this party is pooped, the sun is still stronger than anything we can beam. It might trickle charge. The rays that decrease exponentially with distance, coming from. 93 million miles away, still roasts us. Solar power is insane.

        Edit: astronomers did actually beam a laser and get seen by the ISS. They used a very powerful, focused blue laser and tracking software to aim it on a powered mount. The tracking was necessary because they had to shine it when it was not illuminated. When we see the ISS lit in the night sky, they’re in full sun. The astronaut, Don Pettit who has an extensive photo portfolio, reported seeing a dim, flickering blue light coming from the ground and got a picture. He also saw the spotlights flashing. https://www.universetoday.com/93987/amateur-astronomers-flash-the-space-station/

      • StarDreamer@lemmy.blahaj.zone
        link
        fedilink
        English
        arrow-up
        2
        arrow-down
        1
        ·
        10 months ago

        Wouldn’t shining back be counterproductive for this? You want the solar panels to harness the energy, not returning it to sender

        • XeroxCool@lemmy.world
          link
          fedilink
          English
          arrow-up
          1
          ·
          9 months ago

          Beaming the light back is a reference to completely separate items left on the moon: 6 reflectors (3 Apollo, 2 lunokhod, and 1 chandrayaan). It’s a grid of reflector cells like a huge, metal version of the reflectors you see on cars and bicycles. By measuring the time between shining the laser and recording it’s return, scientists can measure the exact distance to the moon and how it’s changing - both it’s orbital wobble and it’s drift.

          So you’re correct, there’s no desire to have the laser bounce of the solar panels. The comment was just citing the existence of a light source powerful enough to reach the moon from earth.

          • StarDreamer@lemmy.blahaj.zone
            link
            fedilink
            English
            arrow-up
            2
            ·
            9 months ago

            I’m familiar with the Apollo retro-reflectors. Though in all seriousness I doubt a laser would provide a substantial amount of power (unless you have a specialty designed energy collector like in RFID)