Supermoon: Supermoon Questions

Dean, a grade six student struggling with his homework, stood near the window gazing at the moon. “Is there such a thing as a supermoon?” he asked his sister, Denise, a high-school student. "Isn’t every moon a super moon?”

“Do you know what the earth-moon-sun system is?” she asked.

Dean shook his head.

“On March nineteenth, 2011, there was a supermoon. It was too cloudy to see it, but I wrote an essay on it.”

“You did?”

“The name supermoon was coined by astrologer Richard Nolle, in 1979.” 

Denise had his full attention now.

“A supermoon is…a new or full moon which occurs with the moon at or near (within 90% of) its closest approach to earth in a given orbit (perigee). In short, earth, moon and sun are all in a line, with moon in its nearest approach to earth." 

“With a ruler, I could put the earth, moon and sun in a straight line, right? Could I calculate how close the moon came to the earth with calipers?” asked Dean. “What is ‘perigee’?”

“A perigee-syzygy of the earth-moon-sun system or supermoon is a full or new moon that coincides with a close approach by the moon to the earth.” 

“Perigee-syzygy, those would be great words for a spelling bee, wouldn't they?” asked Dean, laughing as she struggled to pronounce the words.

“Come on, Dean, get serious.”

Suspecting this was beyond his understanding, she cut out three circles, labeled them earth, moon and sun, and placed them in a straight line.

“Great! When the earth, moon and sun are in a straight line and the moon is closer to the earth than usual, it’s a supermoon? I don’t have to do this assignment, do I? I could just use the three circles, right?”

“Dean, do your assignment!”

“Did the supermoon cause the tsunami and earthquake in Japan?”

“You ask too many questions. What do you think?”