Earth has been sending out radio messages for about 115 years, so detection equipment on a hypothetical planet 115 light-years away might just now begin receiving them. What is the parallax angle subtended by a system at this distance

blue light is scattered in different directions by the tiny molecules of air. blue is scattered more than other colours because it has a shorter distance to travel which results in smaller waves. this is why we see a blue sky most of the time.

answercollision;