Answer:
A solar flare as it may harm satellites and aircrafts flying near poles
Explanation:
Since solar flare is electro magnetic waves going to Earth the waves will mostly get absorbed by the north and south poles resulting in the aurora borealis, but if the solar flare is strong enough it may stop communications and engines in satellites and aircrafts and in result harming them
Answer:
The first one is the right answer.
In order of increasing frequency: Radio, Microwaves, Infrared, Visible light, Ultra-violet, X-rays, Gamma rays. To remember this try:
Rabbits
Mates
In
Very
Unusual
e(X)pensive
Gardens
Expanding and galaxies (and stars) are moving further away.