SKY
All electromagnetic radiation lacks mass. We sometimes use the term photon to refer to light, which is a form of electromagnetic energy. Light has no mass. None.
Spiral.
A general term would be Solar physicist.
As a general term, the person would be called a Martian, but presumably they would have their own personal name as well.
No, the correct term would be melanin.
no or u would be dead as long term gamma kills
I've heard the term for a group of manta rays to be "A fever of manta rays"
Radiology is the medical term meaning the study of x-rays and other imaging studies.
The electromagnetic spectrum.
I think 'reflection' is the term you are looking for.
Radiation .
One term is "mores" (mor-rays).
Angle
Long term exposure can be dangerous.
common point of two rays or lines, note: rays and lines are the same thing!!
"crepuscular rays" is the technical term...
Refraction