TED Conversations

Mary M.
  • Mary M.
  • Fort Lauderdale, FL
  • United States

TEDCRED 100+

This conversation is closed. Start a new conversation
or join one »

Have you seen the ISS?

Did you know that the international space station is visible at night from various points on earth?

You can check out where it is at any time of day by going to this link

http://iss.astroviewer.net

Have you personally seen it? It looks like a bright white light travelling across the sky, it is really neat to think that there are humans up there orbiting the earth and looking down on us.

What are your thoughts on the space station?

Can anyone explain in layman's terms how it stays in a particular orbit?

This is also a video on TED you might enjoy:

video-cady-coleman-talks-to-ted2011-from-the-international-space-station

Related Talks:
Topics: NASA Wonder astronomy how universe works
+1
Share:

Closing Statement from Mary M.

Krisztian and Ed........thank you so much for his interchange of ideas and information.

Keep looking up!!!

Showing single comment thread. View the full conversation.

  • thumb

    Krisztián Pintér 200+

    • 0
    TED Translator
    Feb 22 2013: ah, about the question: it falls, but always misses the earth :) seriously, imagine a cannon ball shot horizontally. as it slopes downwards, sooner or later hits the surface. but what if you fire it fast enough, so as it bends downward, it just follows the curved surface? it will fall forever, but will never actually get any closer. like a dog chasing its tail.
    • thumb

      edward long 100+

      • 0
      Feb 22 2013: Right on! If you fire it from Earth and make it go fast enough (Escape Velocity) it will overcome the Earth's gravitational pull sufficiently to go right through Earth's atmosphere off into space where it will either continue moving away from Earth, or finally slow-down enough to settle into a state of eqilibrium called an orbit.

      • Mary M. 100+

        • 0
        Feb 22 2013: Thanks Ed.

        Have you seen the ISS up over Arizona?

        The night sky there can be so clear.....perfect for observing the skies at night.
        • thumb

          edward long 100+

          • 0
          Feb 23 2013: We have a good astronomy club that hosts monthly star parties at the local observatory. Those folks enjoy the ISS very much. At some point in the evening one of them will announce, "Watch bearing 190 and azimuth 75 (high in the Southern sky) in two minutes there will be an Iridium Flare." And sure enough there is a sudden bright light reflecting off a satellite, very dramatic. Some of them have taken photos of the ISS through their telescopes. Rumor has it one amateur got a photo from Earth showing an astronaut working outside the space station in orbit! Fantastic stuff.

      • Mary M. 100+

        • 0
        Feb 23 2013: Wow Ed!

        How cool to be at one of those star parties.

        Several times in the past when we have driven through the darkness of the Everglades I stare out the car window in awe of the stars. Sadly though we have so much light coming from all the cities along the coast that the view is not so good, but at least it is much better than from our front door.

        There is a site where you can see the time lapse photography from a station in Chile where they observe the Milky Way.......really beautiful. I learned about it through one of the TEDster's comments on the talk above. It's worth a visit.

        The best view of space I've had has been from the island of Hispanola......saw the Milky Way while up in a mountain riding a motorcycle.......almost fell off too!! The site was so incredible.

    • Mary M. 100+

      • 0
      Feb 22 2013: Thanks for that explanation.

      I really want to know how it varies in orbit.

      Because sometimes it's orbit takes it above Florida, and sometimes it doesn't.

      Does this have to do with the tilting of the earth? Or do they program the station to move?
      • thumb

        Krisztián Pintér 200+

        • 0
        TED Translator
        Feb 22 2013: no it has to do with tilting, but not of the earth, but between the satellite orbit and the equator. and it has to do with the fact that you can't fill the day with orbital periods. it takes about 93 minutes to go a full circle. that means it makes 15.6 circles a day. because of that 0.6 at the end, after exactly 15 orbits, the ISS returns to the same point. but the earth did not manage to get there just yet, it still has a little to go to finish its first turn. but the ISS won't wait of course, and it starts to sweep a line over a different area, parallel to the one yesterday.

        • Mary M. 100+

          • 0
          Feb 22 2013: ok, I'm not understanding.......I read your explanation several times :P

          If it doesn't have to do with the earth's tilt then shouldn't the orbit be always over the same line the entire 15.6 circles......or are you saying that because the earth is also moving (rotating) then this affects the iss?

          Explain to me what does the equator have to do with it.....is it it's protrusion...or the magnetic fields of north and south pole....or what?

          Thanks for your patience....I am really trying to understand to be able to explain it to my kids.
      • thumb

        Krisztián Pintér 200+

        • 0
        TED Translator
        Feb 22 2013: it has nothing to do with anything outside earth, and it is pure geometry, nothing else is involved.

        imagine a strange merry-go-round that has two rings, one inside the other, and they are at an angle to each other. they only meet in two points. also, the two rings are not rotating at the same speed. kids touch hands. then they go around, but one will complete a circle sooner, so they won't meet again. the same kid in the inner circle will touch hands with a different kid on the outer circle.

        • Mary M. 100+

          • 0
          Feb 22 2013: I was really lousy at geometry.

          But, I am going to reread your explanations, and think and draw and hopefully I will figure it out and be able to explain it to the kids.

          Thanks.
      • thumb

        edward long 100+

        • +1
        Feb 23 2013: Here's an excerpt from Science Officer Ed Lu's's email letter to Earthlings from aboard the ISS:
        ". . . our orbit hoop slowly rotates due to the fact that the Earth isn't quite a perfect sphere. This turns out to apply a torque to our orbit which makes it slowly shift westward with respect to the sun . . . It is the same effect that makes a spinning top wobble. In effect our orbit is like a large top, and the fact that the Earth has a bit of a bulge around the equator causes our orbit hoop to wobble slowly."

        • Mary M. 100+

          • 0
          Feb 23 2013: AHA!

          That is exactly the explanation I needed.

          So Krisztian mentions something about the equator.......and geometry....but here Ed Lu does a fabulous job of explaning it. Now I can even due a simulation with a top, great!!

          Thanks Ed.......let me give you a telescope and call you an astronomer :D

Showing single comment thread. View the full conversation.