What develops two tails when it gets closer to the sun?
When comets gets closer to the heat of the Sun, they start to evaporate. gas and dust form long tails that point in the direction of the strongest gravity field. we can see the suns light reflect from the matter that makes up the tail. These tails can be millions of miles long and don't travel in the wake of the comet.
The seasons are caused by the tilt of the earth relative to the sun. The earths axis is tilted and not perfectly parallel with the sun's axis. This means that as the earth circles the sun half the planet will be closer to the sun then the other. When half is closer that is summer. (closer = hotter). When it is farthest away that is winter (father = colder). Spring and fall are the transition…
The Earth would have to be a lot closer to the sun to make any difference. Every year, as the Earth goes around its orbit it gets a couple million miles closer to the sun, and then a couple million miles farther away. If you moved the Earth close enough to the sun, it would get warmer, but that would have to be many million miles.