The Changing Sky Analyzing Images of the Sky As Time Goes By with Rick Kang Public Education/Outreach Coordinator Pine Mt. Electronic Universe

“Cradle-Cam” CCD was used by students to acquire sky data.

A CCD (Charge Coupled Device) is the small grid of silicon that actually creates the picture (image) in a DIGITAL CAMERA. CCDs convert the energy of the incoming light (PHOTONS) into ELECTRICAL CHARGE (ELECTRONS)

OMSI Space Camp 9th-10th grade students set up camera outside at PMO, Aug 06. Wide Field.

For each direction (S, W, N, E) we took two images 5 minutes apart, and also took a 30 second “time exposure” to record trails.

Looking to South Horizon

Add LITTLE ARROWS to South Stars to show your prediction of their location 5 mins later. Please ONLY consider the few stars above Southern Horizon, we’ll work on others one section at a time. Should all your arrows for stars above one horizon point the same direction, or in various directions? Consider the idea of a Constellation.

South horizon comparison

30 second South Trails, correct arrows on your diagram.

Looking to Western Horizon

Add LITTLE ARROWS to West Stars to show your prediction of their location 5 mins later..

Western horizon comparison

30 second West Trails, correct arrows on your diagram 30 second West Trails, correct arrows on your diagram. Not meteor trails, why not?

Looking to Northern Horizon

ALERT! DO NOT MARK ANY ARROWS ON POLARIS NOR ITS FOUR SURROUNDING STARS YET! Add LITTLE ARROWS to North Stars to show your prediction of their location 5 mins later.

Northern horizon comparison see the meteor?

30 second North Trails, correct arrows on your diagram.

Looking to Eastern Horizon

Add LITTLE ARROWS to East Stars to show your predictions of their location 5 mins later.

Eastern horizon comparison

30 second East Trails, correct arrows on your diagram.

With all FOUR HORIZON APPARENT MOTION DIAGRAMS DONE, DO YOU SEE AN OVERALL PATTERN?

Now let’s consider POLARIS and its surrounding stars: Add tiny arrows to indicate which of these stars will appear to move if we wait for 10 minutes. Polaris *

10 minute Polaris Trails, correct arrows on your diagram.

Does Polaris need an arrow? Is your motion consistent with your other four pieces of data?

INQUIRY QUESTIONS Why do the stars APPEAR to circle the sky around Polaris? Why does Polaris appear as the central star, and why doesn’t Polaris appear to move?

Write a “CLAIM” about your observations and analysis. Example: Stars appear to circle around Polaris BECAUSE stars follow curved tracks within the spiral arms of our Galaxy.

Can you think of several explanations that would prove your claim true or prove your claim false?

Can you come up with ideas or experiments/observations to validate or to dismiss any of the claims made by you or your associates?

What do you think is the most likely simple explanation for what you’ve just observed happen to the sky over several minutes of time?

Now let’s consider how the sky might APPEAR to change over LONGER periods of time:

Remember the first South Horizon View?

If you return 24 hours later, sketch apparent motions of key stars relative to tree/horizon

Comparison South Horizon Night 1 to Night 2 – draw arrows on your diagram.

How about night 3? Sketch your prediction.

Comparison of Night 2 to Night 3 SAME CLOCK TIME

Sketch your prediction for Northern Sky night 1 and night 2

Here’s the Northern Sky comparisons, SAME CLOCK TIME, 24 hours apart – Sketch arrows on your diagram.

What’s your “CLAIM” for the sky motion that you’ve just seen?

Can you come up with some evidence/explanations and arguments for true or false?

What might be the most reasonable explanation What might be the most reasonable explanation? Be careful of the terminology that you use.

How many times have you personally been around the Sun? What’s the evidence for your travels? How often do you make the trip?

Latest Word on PLUTO: