[Profpat]

That's a great link Allen thanks.

One question regarding the article:
Jets from supermassive black holes produce tremendous radiation in the form of X-rays, gamma rays and electrons traveling close to the speed of light. Evans said, however, that the X-ray and gamma-ray photons would ultimately do the most damage to planets

Why wouldn't it be at the speed of light, since it is light? Is it the interaction of space which appears to slow the speed?

Best to you,

Pat