The glowing head of a comet is known as the

It's called a coma! (:
Something interesting about a comet is that it basically has four parts -
a nucleus, a coma, a dust tail and an ion tail, and the plasma tail of the comet is extremely hard to see by the human eye!
I hope all is well, and you pass! Good luck, rockstar! (: If you need anymore help, or even have any comments - let me know! (:

No because the eaeht is on a 23.5 degree axis tilt and so when it is winter the northern hemisphere is pointing away from the sun and the soutubern hemisphere is pointing toward the sun