Auroras are lights that appear at earth’s northern and southern poles. what is the main cause of an aurora?

it cools slower in the earth meaning the crystals have more time to form than lava on the surface

the corpus luteum secretes estrogens and progesterone. the latter hormone causes changes in the uterus that make it more suitable for implantation of the fertilized ovum and the nourishment of the embryo. if the egg is not fertilized, the corpus luteum becomes inactive after 10–14 days, and menstruation occurs.

i hope this : )