Thursday, September 9, 2010

The Kids Are Far Out - part one

To turn kids on to science and astronomy was the reason we all gathered at the annual Cosmic Carnival outreach event held at the Albuquerque International Balloon Museum this past Sunday, September 5.

The joint was jumping!

Dave Dooling of the National Solar Observatory deflates the Sun.

Len Duda of Sandia National Labs inspires a future engineer.

I met some “far out” kids (and adults) who like astronomy and stargazing, and invited them to write a comment or pose a question to be published on my blog. Liam from Albuquerque, age 10, had this to say:

“My favorite constellation is ‘o-Ryann.’ My stepsister’s name is Ryann. She is three months younger than me. Sometimes we get into arguments, but most of the time I like her. I find Orion easy to recognize.”

Ditto, Liam! That distinctive hourglass shape, along with the three diagonal Belt stars in the middle, makes Orion the Hunter quite easy to spot in the winter sky, even if you’re a beginner. Read more here.

Wow, how lucky are the kids who call Dara from Albuquerque, age 40, “Mom.” She shared this story:

“Each time we take our sons camping, they are a little older and can pick out more things in the night sky. This summer our 5 year old spent hours looking for his favorite constellation, but never found it (must be the wrong time of year for Delphinus). But we had a great time counting shooting stars and naming our own constellations.”

Right you are, Dara. The delightful little constellation of Delphinus the Dolphin leaps its way into our hearts in autumn. Starting in late September, look for it after sunset, just west of the Great Square of Pegasus. Read more here.

Finally, a young lady named Vaidehi from Lone Tree, Colorado, age 8, posed this question:

“Why do the stars change over a year?”

Excellent question, Vaidehi! Many adults don’t know the answer to that question either. So, why do we say that Orion is a “winter constellation” and Delphinus is an “autumn constellation?” And why can we see Scorpius the Scorpion in the summer, but not in the winter? In other words, why are the stars seasonal?

The Earth is in orbit around the Sun 365 days a year, right? Because we’re always moving along this path around the Sun, each night when we spin around to face the night sky, we don’t have exactly the same view we had the night before. Although it won’t be obvious to you, the night sky and its star patterns have shifted slightly to the west, or right. This is because the Earth has moved slightly eastward in its orbit, or toward the left.

This continuous westward shifting of the stars will become more noticeable to you as the months pass and seasons change. For example, you might notice that the constellations you enjoyed in summer are moving farther and farther to the west in autumn, until finally they are below the western horizon after sunset and no longer visible.

The diagram below shows an example of this, using the constellations of the zodiac. If we were standing on the Earth shown in the diagram (the black circle), at night we would look out at the constellation Pisces the Fishes. But six months later in its orbit, when Earth was on the other side of the Sun, we would look out at the constellation Virgo the Maiden at night.

Diagram by Dr. Guy Worthey

Because we’re always in motion, we’re always looking out at different “slices” of the night sky.