why Do we have these telescopes to see these galaxy's and stars and we know about the cosmic web way out of our reach we have the technology to see that why not these planets? Is there a way we could use these telescopes or even the satellites to bounce light off of in order to see these exoplanets that are in the TRAPPIST-1?

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    $\begingroup$ There is no way anyone can know why you are feeling something. Please try to rephrase your question so that it can be answered objectively. Also, one question per post, please. $\endgroup$ Commented Feb 25, 2017 at 17:35
  • $\begingroup$ If you can't answer my question then don't comment. Looking for professional answers not someone who will pick apart how I asked. $\endgroup$ Commented Feb 25, 2017 at 18:23
  • $\begingroup$ It's up to you, but if you don't fix it, it will likely get closed by the community. $\endgroup$ Commented Feb 25, 2017 at 18:36
  • $\begingroup$ I think this falls in the scope of "...good answers would be too long for this format. Please add details to narrow the answer set or to isolate an issue that can be answered in a few paragraphs." . In this particular case there is a chain of bits of rationale that you need, some from this forum some better sourced from Astronomy SE. I suspect the idea of what else can we learn by pointing other assets at it is cutting edge. $\endgroup$
    – Puffin
    Commented Feb 25, 2017 at 18:48
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    $\begingroup$ A simple sanity check, just to make a start at getting an idea of the problem, would be to check telescope optical aperture (say Hubble at 2.4m or any from here en.wikipedia.org/wiki/… ) and the angular resolution formula here en.wikipedia.org/wiki/Optical_telescope#Angular_resolution) to see what size that would be at 40 light years. This will help frame the problem, thereafter perhaps a good step would be to think about what you really mean by "to see these exoplanets". $\endgroup$
    – Puffin
    Commented Feb 25, 2017 at 18:59

1 Answer 1


Answering just the last sentence, because the rest is already addressed elsewhere:

That exoplanet is right next to a star, so it is illuminated by a lot of light. But that star is 40 lightyears away from us, so only a few photons of its light reach us, and even fewer photons of starlight reflected by its planets reach us.

Any light we could send to that star (in order to better see its planets) is completely negligible compared to the light our sun already sends that way. If you could travel to Trappist-1 and look back at our sun, you'd see a tiny star, which adds a negligible amount of illumination to Trappist-1 and its planets.


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