Comment I don't get why scientists need real eclipses (Score 2) 19
I understand that, by sheer coincidence, the moon has the right size and is currently at the right distance to mask the just enough of the sun and let only photons from the sun's upper atmosphere and corona through, making their observation easier.
But why is the moon needed? Why are even clever sun-blocking satellites needed? Do sun-blocking things need to be placed far away to observe the corona? Couldn't a beer coaster placed a few feet away from the telescope serve the same purpose?
I'm oversimplifying of course, but you get the idea.
The only reason I can think of is that the farther the sun-blocking object, the less fuzzy its boundary is when the observed through a telescope focused at infinity, making the moon truly useful when observing the thin boundary layer between the sun and the corona. Other than that, I don't see why a beer coaster - or perhaps a larger round object placed a bit farther out - wouldn't do the job.
Perhaps a reader who is better versed in solar observations can shed some light (pun not intended