How far away from our system would Earth be detectable?

[willpittenger]

Again, you have it backwards. Go <b>TO</b> Alpha Centari and attempt to prove the the people (assume there are some for the sake of the argument) there that Earth exists. <div class="Discussion_UserSignature"> <hr style="margin-top:0.5em;margin-bottom:0.5em" />Will Pittenger<hr style="margin-top:0.5em;margin-bottom:0.5em" />Add this user box to your Wikipedia User Page to show your support for the SDC forums: <div style="margin-left:1em">{{User:Will Pittenger/User Boxes/Space.com Account}}</div> </div>

 

[willpittenger]

I do not know how people are so confused about this. I am not attemptting to detect planets in the Centari system. Rather, I was attempting to use how readily they could detect OUR Earth from THERE. That would then establish what systems we could detect Earth-like worlds at. <div class="Discussion_UserSignature"> <hr style="margin-top:0.5em;margin-bottom:0.5em" />Will Pittenger<hr style="margin-top:0.5em;margin-bottom:0.5em" />Add this user box to your Wikipedia User Page to show your support for the SDC forums: <div style="margin-left:1em">{{User:Will Pittenger/User Boxes/Space.com Account}}</div> </div>

 

[qso1]

willpittenger:<br />How far away from our system would Earth be detectable?<br /><br />I do not know how people are so confused about this. I am not attemptting to detect planets in the Centari system.<br /><br />Me:<br />No confusion here, I knew from the start you were not trying to detect planets around AC...I refered to detection from the Centauri system because that would be the appropriate reversal of detecting Earth from Centauri. We currently do not have the capability to detect earthsized or earthlike worlds at Alpha Centauri so conversely, per your question, it would stand to reason that they would not have the ability to detect us using our present day technology.<br /><br />The fact we have yet to detect an earthlike world orbiting any star as yet is enough to know the same would apply in reverse from another star system, even Alpha Centauri. The difference I mentioned was that since AC is a binary system (Actual trinary if Proxima is actually part of that system), we would actually have a slightly tougher time establishing the presence of an earthlike world there due to the orbital mechanics complexities so in reverse...if it were somehow a race to see who could find earth or an earthlike world at AC first. AC would have an advantage due to us orbiting a single star. <div class="Discussion_UserSignature"> <p><strong>My borrowed quote for the time being:</strong></p><p><em>There are three kinds of people in life. Those who make it happen, those who watch it happen...and those who do not know what happened.</em></p> </div>

 

[qso1]

willpittenger:<br />Again, you have it backwards. Go TO Alpha Centari and attempt to prove the the people (assume there are some for the sake of the argument) there that Earth exists. <br /><br />Me:<br />this is exactly the point were trying to help with. By imagining that we could have beings at an earthlike world orbiting AC, we, or at least I know that since we have not detected an earthlike world there as of yet. With the same technology, there is no reason they could do the same except for the possibility they would detect us maybe a year, five years before we would detect them because our system is a single star, less complex in verifying the orbits of planets as a whole. Especially if the detection is an indirect one using a technique such as radial velocity.<br /><br />In short, the answer to your question is that we are not yet detectable from AC using our technology but could be five years before we could detect them. Meaning that in my estimation, we are 5 to 10 years from detecting an earthlike world there.<br /><br />Even with all that, the truth is, nobody can really know for sure. We might detect an earthlike world 5 years from now at AC, or it may be 25 years away which of course, if were using our tech at AC to detect us, same thing applies. <div class="Discussion_UserSignature"> <p><strong>My borrowed quote for the time being:</strong></p><p><em>There are three kinds of people in life. Those who make it happen, those who watch it happen...and those who do not know what happened.</em></p> </div>

 

[agnau]

My thought was actually you would have an easier time spotting earth from Pluto and getting a more-acurate picture (although still being close to 4 times closer to our sun) of what you would see at AC. If there are no problems seeing earth from there, move to Sedna, even further out. The outer solar system is about 1.5 ly out from the sun. If you can place a test there (which maybe possible at the end of the New Horizons mission) you can see what the central system looks like.<br /><br />These are the stepping stones that our technology will go through. I am certain one day we will launch a craft toward AC and have it send telescopic images of our system back to us. It will be an amazing set of views as we drift into the background of the sheer vastness of space.

 

[qso1]

You are correct, It would be much easier to see Earth from Pluto or Sedna as opposed to trying to see it from AC. Just to reinforce this fact, I once did a paper excercise in response to a question asked by someone as to whether Pluto was orbiting the sun or AC. I had to visualize the distance and did so on a sheet of paper. IIRC (I did this in 1983), I put a dot at the top and one at the bottom of an 8 X 11 inch piece of paper. The dots encompassed a diameter of roughly 50 billion miles while the distance between the dots was roughly 26 trillion miles, the distance to AC. It became obvious Pluto was orbiting the sun (Well within the diameter of the dot on paper). And for this question, equally obvious that Pluto would be a much better vantage point than AC for observing Earth. <div class="Discussion_UserSignature"> <p><strong>My borrowed quote for the time being:</strong></p><p><em>There are three kinds of people in life. Those who make it happen, those who watch it happen...and those who do not know what happened.</em></p> </div>

 

[newtonian]

willpittenger - On your last point - I already responded on that by citing Isaiah 40 and noting that we are (Isaiah 40:23) . . .as a mere unreality. . . from long distances.<br /><br />See my above posts. Us primitive (by comparison) humans could not detect civilizations from the alpha centauri system - yet.<br /><br />

 

[willpittenger]

The orbital mechanics part is why I specifically wanted people to ignore attempting to find a planet there. <div class="Discussion_UserSignature"> <hr style="margin-top:0.5em;margin-bottom:0.5em" />Will Pittenger<hr style="margin-top:0.5em;margin-bottom:0.5em" />Add this user box to your Wikipedia User Page to show your support for the SDC forums: <div style="margin-left:1em">{{User:Will Pittenger/User Boxes/Space.com Account}}</div> </div>

 

[qso1]

I pointed the orbital complexity of a binary because the natural inclination for an answer to your question was to reverse the scenario which myself and a couple others did here.<br /><br />In that sense, I understood what you were after. <div class="Discussion_UserSignature"> <p><strong>My borrowed quote for the time being:</strong></p><p><em>There are three kinds of people in life. Those who make it happen, those who watch it happen...and those who do not know what happened.</em></p> </div>