Since the light from a distant star is a point source for any measurement that we want to make,…
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How to Compute the Distance Between Two Stars
This is actually an application of spherical trigonometry. A good description of this calculation, including an online tool to…

Can a Moon Alternately Orbit Two Planets?
I don’t believe that the scenario you describe, were a moon is effectively shared by two planets in a…

Are There EUV Intensity Measurements of the Earth’s Surface?
I found two satellite systems that appear to measure EUV emission. The Ionospheric Connection Explorer (ICON) and the Geostationary…

What if the Earth Became Tidally Locked to the Sun?
Actually, this question has been quite well answered on INSH. Basically, it would be all bad. One side of…

Electromagnetic Spectrum Limits
I believe that by definition the electromagnetic spectrum runs from 0 to infinite frequency or wavelength. There are practical…