• Artyom@lemm.ee
    0·
    9 days ago

    The moon doesn’t actually protect the Earth from asteroids. It’s a net-zero because the extra mass attracts more asteroids.

    • LostXOR@fedia.io
      0·
      9 days ago

      It’s not really about “attracting” asteroids, it’s more about their orbital trajectory happening to intersect the Earth’s at the right time. I think the Moon’s gravity is about as likely to redirect an asteroid towards the Earth as it is away, but the Moon also physically intercepts some asteroids, so the net effect would be a slight decrease in Earthly asteroid impacts.

    • chillinit@lemmynsfw.com
      0·
      9 days ago

      How do the exacerbaters and mitigators cancel each other out to yield exactly net zero?

      Hell, you can even have a 1% allowance. Just explain how it’s even close.

      • expatriado@lemmy.world
        0·
        9 days ago

        agree, would make more sense a comet asking Neptune for directions, and then colliding with Jupiter with Pac-Man face

      • frezik@midwest.social
        0·
        8 days ago

        It’s way more complicated than that:

        https://www.youtube.com/watch?v=1zu41rrc_Ng

        The way the complicated orbital mechanics work, there is a “gate” which is the only place where asteroids/comets/whatever can cross Jupiter’s orbit. This doesn’t usually result in them hitting Jupiter, but it does limit their options for hitting Earth.

        Been a while since I watched the video, so I don’t remember all the details, but that should be the basic gist.

    • chillinit@lemmynsfw.com
      0·
      9 days ago

      Here’s a <1pg read about Jupiter and comets.

      Jupiter’s gravity is thought to sling most of these fast-moving ice balls out of the solar system before they can get close to Earth… Without Jupiter nearby, long-period comets would collide with our planet much more frequently.

      Consider that its powerful gravity prevented space rocks orbiting near it from coalescing into a planet, and that’s why our solar system today has an asteroid belt, consisting of hundreds of thousands of small flying chunks of debris. Today, Jupiter’s gravity continues to affect the asteroids – only now it nudges some asteroids toward the sun, where they have the possibility of colliding with Earth.

      Editorial: It’s a double-edged sword that favors us far more often than it doesn’t. The human problem is that it only takes one collision to end us.

      • ThatWeirdGuy1001@lemmy.world
        0·
        9 days ago

        I mean it’s a mathematical inevitability that earth will get hit eventually. Having Jupiter there just gave us better odds. Luck doesn’t last forever though.

      • Tyfud@lemmy.worldEnglish
        0·
        9 days ago

        To clarify, we likely wouldn’t end as a species.

        Dinosaurs were ended with a roughly 10-15km meteroirite hitting earth, and causing months of distortions and damage to the ecosystem that disrupted their way of life enough that they starved or died of other causes.

        They were not nearly as adaptable as we are in modern times.

        To be sure, a lot of progress would die, and life would be greatly disrupted, but we, as a species, would almost certainly survive a similar event.

        • chillinit@lemmynsfw.com
          0·
          9 days ago

          If we humans did not chronically overestimate self and underestimate risk then we’d all choose to kill ourselves. Individuals can be smart. But, when pressured or at scale we’re really fucking stupid.

          causing months of distortions and damage

          It wasn’t months. It was centuries of upheaval before systems restabilized, double digit human generations.

          Sure, the asteroid wouldn’t kill all of humanity. The subsequent choices of the few that remained almost certainly would. We’re fragile, ordinary creatures that just got here and immediately set about killing one another and the planet itself.

        • chillinit@lemmynsfw.com
          0·
          8 days ago

          I see what you mean. But, take out the word “slightly” and it’s also how most of us perceive ourselves and how we should be treated by an authority. It seems exemplified in our anthropomorphized perceptions of most gods.

          • rockerface 🇺🇦@lemm.ee
            0·
            8 days ago

            Yeah, polytheistic gods are basically people, with all consequences thereof. Powerful, but not omnipotent, nor omniscient.

            We’ve been telling stories of those people to make sense of the universe, but the story is ultimately about us.