• Owl@lemm.ee
    link
    fedilink
    English
    arrow-up
    12
    ·
    7 days ago

    can you explain why? cuz that doesnt make sense to me

    • thefartographer@lemm.ee
      link
      fedilink
      arrow-up
      132
      ·
      edit-2
      7 days ago

      The solar system is doing this

      Which makes you go like this

      And while it’s possible to make your way towards the center, it’s difficult

      And this requires less work

    • Boomer Humor Doomergod@lemmy.world
      link
      fedilink
      English
      arrow-up
      17
      ·
      7 days ago

      The earth is going around the sun pretty fast, and you need to counteract that speed to get to the sun.

      But when you’re leaving you can use the earths orbital velocity to give you a boost.

    • MyatZezou@piefed.social
      link
      fedilink
      English
      arrow-up
      14
      ·
      7 days ago

      https://xkcd.com/681_large/

      The sun creates a big gravity well. The earth happens to be quite close to the top of this well (because of the inverse square low). It takes about the same energy to go down and up the gravitational well.

    • mEEGal@lemmy.world
      link
      fedilink
      arrow-up
      10
      ·
      7 days ago

      if your object has just enough velocity to escape Earth’s gravity, it’ll begin orbiting the Sun, it won’t fall directly towards it.

      I’m going to oversimplify this : if you want your object to hit the sun after leaving the Earth, it has to have the velocity of the Earth (30 km/s) but in the opposite direction of it’s orbit around the Sun.

      you also should take into account the massive distance between us anl the Sun (150 million km). so you have to aim properly, otherwise your object is gonna enter a very elliptical orbit

    • scratchee@feddit.uk
      link
      fedilink
      English
      arrow-up
      2
      ·
      edit-2
      4 days ago

      There’s been plenty of explanations already, but here’s a perspective I think can help:

      Your original intuition is entirely correct for an object that appeared next to earth but which isn’t moving relative to the sun. It would fall straight in with very little trouble. If it’s moving a little sideways then it’d need to be nudged to make sure it didn’t miss the sun.

      But the Earth is moving super fast sideways, so an object coming from Earth would need to be nudged a lot to not miss the sun.

    • Bannanable@feddit.nl
      link
      fedilink
      arrow-up
      1
      ·
      edit-2
      7 days ago

      dV also called delta V is the change in velocity required. Higher means more fuel is required and so making the rocket is harder. The earth orbits the sun at a very high speed and so to get to a planet much further inward requires slowing down a lot. You can look up escape velocity which is the velocity required to exit a gravitational body completely.