(An Inuit Sky Tale)
Sun and Moon were sister and brother. They always took part in the copulation games in the young people's house. But one night, as Moon was trying to decide which girl he would try to find when the light was dimmed, his eyes fell upon his sister, and he thought she was the most beautiful of all. He noticed how her clothes were made, and when the lamp had been put out, he found her by feeling his way.
He did this many times. At last, Sun became suspicious, and she took a little soot from the lamp upon her fingers. During the copulation she pressed her fingers against the forehead of the man who took her. And when the lamp was lit again, she saw her brother Moon with soot on his face.
Sun became red and hot with shame. She took a whisk of moss from the heap by the lamp, dipped it in the blubber and lit it, and she ran out.
Moon wanted to follow her, but he was in such a hurry that he didn't get his moss lit very well.
"We must run far away and never see each other again," said Sun. And at the same moment they became spirits and were lifted up in the sky, where they continued their flight.
But Sun has the stronger warmer light, because her whisk of moss burns clearly. Her brother Moon, who pursues her but never can catch up with her, has the weaker colder light.
-taken from Peter Freuchen's Book of the Eskimos
From Rachel Baar's, Kimi Hata's, and Arthur Wendel's ID1 paper.