Far space objects can be observed because light photons emitted from (or reflected by) them, will reach to our telescopes. Light photons, moving with the speed c, travel in a straight line, if their path didn't encounter a massive object. If they do, gravity will literally bend the path of these photons with an amount depending on the mass. This causes an effect called Gravity Lensing (GL).
GL could even duplicate an objects image, more than once. A famous example is the Gravitational Lens G2237 + 0305 (aka Einstein Cross gravity lens), found from
http://hubblesite.org/newscenter/archive/releases/1990/20/image/a/
So, is it possible that light emitted/reflected by Earth will encounter massive objects, fir multiple times, and suffer multiple GL's to change direction with 180 degrees and return to us? Or, can we see an image of this Earth, or even ourselves, coming from some point in space? What would be the possible consequences?
Hi again Ahmed
interesting question. in principle yes that is physically possible. in reality we don't know of anything like that actually occurring though. as you can imagine the circumstances in which it would occur are very specific and thus unlikely.
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