Name: andrew g cantrell Date: 1993 - 1999 Is the moon ever truly
full except during a total solar eclipse? Is there a reason that
the oion nebula appears blue in my telescope? 1) nope, the moon
can't be full during a solar eclipse! (why?) [perhaps you were
thinking of lunar eclipses?] 2) the Orion Nebula is one of the
brightest of the emission nebulae or H II regions (the "H II"
means ionized hydrogen). Emission nebula are usually reddish
because they fluoresce by converting stellar UV radiation into
the hydrogen Balmer lines, especially H-alpha which is in the
red region of the visible spectrum. Why it appears blue could be
due to many reasons having to do with your telescope,
atmospheric conditions, Orion's elevation above the horizon, or
it might actually be blue because of the presence of oxygen in
the nebula. [for those who don't know, the Orion Nebula is the
middle "star" of the three making up "The Hunter's" sword
hanging from his belt... AHA! there is a small cluster of 5 blue
stars inside the nebula.