NHS&DSFC ASTRONOMY CLUB

Creating a model to Predict Hubble’s View of Saturn

With Keith Noll

Saturn's equator is tilted relative to its orbit by 27 degrees, very similar to the 23-degree tilt of the Earth. As Saturn moves along its orbit, first one hemisphere, then the other is tilted towards the Sun. This cyclical change causes seasons on Saturn, just as the changing orientation of Earth's tilt causes seasons on our planet. These Hubble Space Telescope images, captured from 1996 to 2000, show Saturn's rings opening up from just past edge-on to nearly fully as it moves from autumn towards winter in its Northern Hemisphere

The first image in this sequence, on the lower left, was taken soon after the autumnal equinox in Saturn's Northern Hemisphere. By the time of the final image in the sequence, on the upper right, the tilt is nearing its extreme, or winter solstice in the Northern Hemisphere

Your challenge is to use each of the images of Saturn below to find out when Hubble will next view Saturn across the plane of the rings (like looking side-on to a CD).

To do this, follow the procedure below:

1. Use the linked images above and our recommended program ‘WaveJ’ to measure the width and the apparent height [OPU1] of the rings for each image.

Click here for a guide to using WaveJ.

2. Use trigonometry to find the angle below the plane of the rings from which Hubble viewed the images in each case. To find out why this angle is helpful and for help with this click here.

3. Input your angles into the MS Excel program here and transform the sin curve to fit your data by shifting and stretching the basic shape up and down.

Now you can read from your graph when the angle was last 0° and when it will next be 0°.

Hubble took images when the angle was last 0°, click here to see if the date of these images matches your prediction.

If you’ve got this right then your prediction for the next view of Saturn across the plane of the rings will be correct.

Congratulations – you are now prepared for this rare astronomical event!

Click here for a zipped folder of the essential files in this pack (1.7mb)


					Seasons on Saturn
			My Video Hello 1.8Mb mpg My short biography Saturn reflecting the Spectrum Challenge Seasons on Saturn in 3D		Creating a model to Predict Hubble’s View of Saturn With Keith Noll Saturn's equator is tilted relative to its orbit by 27 degrees, very similar to the 23-degree tilt of the Earth. As Saturn moves along its orbit, first one hemisphere, then the other is tilted towards the Sun. This cyclical change causes seasons on Saturn, just as the changing orientation of Earth's tilt causes seasons on our planet. These Hubble Space Telescope images, captured from 1996 to 2000, show Saturn's rings opening up from just past edge-on to nearly fully as it moves from autumn towards winter in its Northern Hemisphere . The first image in this sequence, on the lower left, was taken soon after the autumnal equinox in Saturn's Northern Hemisphere. By the time of the final image in the sequence, on the upper right, the tilt is nearing its extreme, or winter solstice in the Northern Hemisphere Your challenge is to use each of the images of Saturn below to find out when Hubble will next view Saturn across the plane of the rings (like looking side-on to a CD). To do this, follow the procedure below: 1. Use the linked images above and our recommended program ‘WaveJ’ to measure the width and the apparent height [OPU1] of the rings for each image. Click here for a guide to using WaveJ. 2. Use trigonometry to find the angle below the plane of the rings from which Hubble viewed the images in each case. To find out why this angle is helpful and for help with this click here. 3. Input your angles into the MS Excel program here and transform the sin curve to fit your data by shifting and stretching the basic shape up and down. Now you can read from your graph when the angle was last 0° and when it will next be 0°. Hubble took images when the angle was last 0°, click here to see if the date of these images matches your prediction. If you’ve got this right then your prediction for the next view of Saturn across the plane of the rings will be correct. Congratulations – you are now prepared for this rare astronomical event! Click here for a zipped folder of the essential files in this pack (1.7mb)