People smarter than me say the sun will be 99% covered during the 2017 solar eclipse where I live (Portland, OR metro). I am curious to know what it might look like (photo or drawing). Does this photo approximate 99% coverage? Or will there be slightly more sun? Will I still see some of the corona?

enter image description here

  • $\begingroup$ You might want to use stellarium.org (free) for a more accurate (though still not necessarily 100% accurate) simulation. $\endgroup$
    – user21
    Aug 9 '17 at 13:43

At 99% the sun will be reduced to a small sliver. There are simulations on the internet. It will become very notably darker. However, the sun is 400000 times brighter than the full moon, so 1% of the Sun is still 4000 times brighter than the Moon, and so no corona will be visible. You can still damage you eye looking at that sliver.

Since the centre of totality is less than an hour's drive from Portland, if you have a car, and can get out early, you can see totality and the corona (weather permitting)

  • 2
    $\begingroup$ You would be daft not to. There is a huge experiential difference between 99% and 100%. $\endgroup$
    – ProfRob
    Aug 9 '17 at 11:52
  • $\begingroup$ @RobJeffries - The roads will be literally gridlocked. Ugh. Not only will everyone from Portland will be heading south on I-5, so will Seattle which is a couple hours north of here. That normally one hour drive to Salem (in totality zone) will probably take 3-4 hrs or more. Then head back home afterwards. $\endgroup$
    – iMerchant
    Aug 9 '17 at 16:56
  • $\begingroup$ @iMerchant There are people I know from the UK travelling significantly longer and further... $\endgroup$
    – ProfRob
    Aug 9 '17 at 17:11
  • $\begingroup$ 3-4 hrs drive to see a total solar eclipse? Nah, I wouldn't bother if I were you. I mean, a couple of hours would be totally worth it but that's just getting silly. $\endgroup$ Aug 10 '17 at 11:34

The sun will still be very very bright and I advise you not to look at at directly. If you were to, you would not see any corona, since it is very faint, relative to the sun (even 1%). The sun will look a bit like your photo, but I'd say with a little more light.

However there will be a very noticeable darkening of the environment around you, to the extent that any local wildlife will likely start make preparations for nighttime. It will also cool down.

As totality approaches, gaps between shadows made by, for example leaves on trees, will progressively show the shape of the partially obscured sun - similarly with pinhole cameras.


Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.