How do you know?

During one of my karate classes, one of the dojo kids pointed to the sky, and said that's a satellite.

I asked, "how do you know"?
He said, "it's not blinking. So it's a satellite."
"Why must a satellite not blink? Maybe it's a planet or a plane?"
"Only satellite doesn't blink."
"And how do you know? Planes in the sky also doesn't blink. Why must a star blink?"
"Even my teacher says that's a satellite."
"And how do you know your teacher is right?"
"She's a teacher."
"Maybe your teacher is wrong?"

And he chose to ignore me, in utter frustration. Ah... the mind of a ten year old boy. Hehe.