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Scientific importance of total Solar eclipses?

  1. Mar 31, 2015 #1
    I was wondering whether there is an actual scientific point of taking ground-based photographs of the Solar corona during total eclipses on Earth. It seems to attract a lot of attention from well equipped amateurs around the world and the pictures of the fine plasma structure surely look great, but shouldn't such conditions be routinely achievable in space by simply obscuring the Solar disc with a little sun shield?

    In other words, is there any scientific aspect of a ground-based total Solar eclipse observation that would not be achievable routinely with space-based telescopes?

    Thanks for answers.

  2. jcsd
  3. Mar 31, 2015 #2


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    I am not an astrophysicist, but I heard the other day on the radio a solar expert who answered this very question by a resounding no!
  4. Mar 31, 2015 #3


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    My understanding would be: coronal imaging (we already see the corona naked eye during an eclipse). But then again artificial eclipses (coronographs, sample image below) blocking the light from the disk are how this is done in practice nowadays, so the resounding no sounds right.


    It wasn't always the case though, wasn't an eclipse used for an early test of GR (lensing of distant stars by the Sun)?
    Last edited: Mar 31, 2015
  5. Mar 31, 2015 #4
    Yes, it was eddington who did the experiment with a total solar eclipse to prove einstein was correct (though I think it was heavily debated back then)
  6. Mar 31, 2015 #5


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    Ah yes, Eddington, thanks. It's strange to think that something as simple as a coronograph wasn't available yet at the time, I wonder what the issue was.

    Edit. Ah yes daylight. Thanks @mathman.
    Last edited: Mar 31, 2015
  7. Mar 31, 2015 #6
    Probably human error and proving Newtons theory wrong, or something like that :p
  8. Mar 31, 2015 #7
    Oh yes, I knew about the historical importance and the time when space telescopes simply were not an option. I was thinking of some present day applications.

    While reading online, I came across an article claiming that the ground based observations during eclipses are better suited for imaging of the closest parts of the corona to the Sun disc, justifying it a bit unsatisfactorily. Do you know anything about that?
  9. Mar 31, 2015 #8
    Maybe on earth, but I would think you could yield the same results (or similar enough) from a telescope in space using a disc to block the light in the telescope. Of course, I could be very wrong :p
  10. Mar 31, 2015 #9


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    Interesting, although I would suspect this must be a pretty special case : there are few eclipses and each one is only visible for a few minutes, and only from a small patch of the earth - so any advantage is limited to a couple minutes observation from a few telescopes, vs 100s of days per year from many solar observatories for coronographs, and these rare observations must trump what one can infer from a very large number of not-quite-as-good ones. But I'd be interested to hear more about it.
  11. Mar 31, 2015 #10


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    For Eddington it was not enough to block the sun. It was also necessary to turn off the skylight in order to see the stars.
  12. Mar 31, 2015 #11


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    Gee do I feel stupid now :)
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