Saturn Poetry
Two poems are provided to analyze and discuss. Students can write their own poetry about Saturn and Cassini. See Figures 1 and 2 under "Materials" (page 213) for the full-size poem texts to reproduce.
Poem 1 - A Sense of Grandeur
T O P I C
Ask students to analyze and discuss the poem. The discussion can be approached from both the scientific and the poetic aspects. Use information from the Questions and Answers (Appendix 1) to stimulate students' questions and responses.
A C T I V I T Y
Have students write their own poems about Saturn, the rings, and the moons, and what Cassini might discover.
Poem 2 - Sensing the "Titan-ic"
D I S C U S S I O N - A N D - A C T I V I T Y
Ask students to analyze the poem. Have them write down a list of facts they have discerned from the poem, and also a list of questions they have. See Background for Poem 2 for supplementary material that includes facts the students might discern, along with supporting notes to assist your discussion with the students and to answer questions that may arise from their studies of the poem. The Glossary provides help with technical terms.
| Paper | FIGURE | COPIES |
| Pencils | 1 | 1 per student |
| | 2 | 1 per group |
Background for Poem 2
Sensing the "Titan-ic"
- Ask students: Why do you think the poet chose this title? Is there more than one way of interpreting the title? For example, an interpretation might be that we are sensing Titan with Cassini-Huygens instruments (sensors), and
sensing the monumental nature of exploring an unknown world. To support their interpretations, have students look up the definition of the word "titanic."
I. What wonders 'wait our robot's eye
A billion miles away?
What treasures will Cassini spy
With Titan on display?
II. Old Huygens was the first to view
Great Saturn's largest moon.
In 1655 he knew
It kept with Kepler's tune.
F A C T S
1.Cassini is the name of the robotic spacecraft that will study Titan.
2. Titan is a billion miles away.
3.Titan is Saturn's largest moon, so Saturn must be a billion miles away as well, and Cassini must be going to visit the Saturn system.
4.Huygens discovered Titan in 1655.
5.Huygens knew of Kepler's Laws of orbital motion and applied them to learn of Titan's
orbit.
S U P P O R T I N G - N O T E S
- Saturn is actually a bit less than a billion miles away, but this is the correct order of magnitude. It is more like 0.87 billion miles = 870 million miles (1.4 billion kilometers) from Earth on the shortest straight-line path. How ever, the Cassini spacecraft will use gravity assists from Venus (twice), Earth, and Jupiter, and thus must travel nearly three times this far before reaching Titan. The trip will take nearly 7 years.
- Titan is Saturn's largest moon by far. Its diameter (5,150 kilometers) is more than three times greater than that of any other moon of Saturn. Ganymede, a moon of Jupiter, is the largest moon in the Solar System; Titan is second largest.
Titan's diameter is about 25% larger than that of Earth's Moon. The distance around Titan is a little less than halfway around Earth.
- In spring 1655, Dutch astronomer Christiaan Huygens (HOY-genz) announced the first discovery of a moon of Saturn.
- "Kepler's tune" is an allusion to Kepler's original motivation to reveal the "music of the spheres" as he studied Tycho Brahe's extensive observational data looking for the planetary laws of motion he would eventually discover.
III. Then Kuiper would at Titan peer
With "eyes" of infrared,
Detecting there an atmosphere -
Perhaps it wasn't dead!
F A C T S
1. Kuiper looked at Titan with a telescope and used a detector sensitive to near-infrared wavelengths. He discovered evidence of an atmosphere.
2. If Titan has an atmosphere, perhaps there could be life there.
S U P P O R T I N G - N O T E S
- Gerard Kuiper (KOY-per), Dutch-born American astronomer, was a pioneer in infrared astronomy. He was interested in finding out if any of the moons in the Solar System had an atmosphere. He studied the light reflected off the 10 largest moons, and in 1944 reported that Titan alone had an atmosphere that could be easily detected. Kuiper observed the spectral signature of methane on Titan.
- We can infer that Kuiper's observation was made no earlier than the 1930s because scientists only observed the sky in wavelengths of visible light until then. Today, we view the Universe across the entire electromagnetic spectrum - radio, microwave, infrared, visible, ultraviolet, x-ray, and gamma ray. See the Glossary for more information; the Appendices include an illustration of the electromagnetic spectrum.
- With a detectable organic compound like methane in the atmosphere, it was very natural to raise the question about whether life existed there, had existed there, or might yet exist there.
IV. A prebiotic earthly place?
The thought of this astounds.
A moon, unlike our Old Man's face,
Where nitrogen abounds.
F A C T S
1.Titan might be like Earth before life evolved here ("prebiotic earthly place").
2.Titan is not at all like our Moon ("our Old Man's face" refers to the Old Man in the Moon).
3. Titan's atmosphere is abundant with nitrogen.
S U P P O R T I N G - N O T E S
- A "prebiotic earthly place" would be rife with organic chemistry.
- Our Moon has no substantive atmosphere, and to our knowledge neither do any of the other 60 or so moons in the Solar System. Titan is unique and holds the possibility of teaching us something about the origin of life on Earth.
- Before Voyager 1's flyby of Titan in 1980, only methane and a few other simple hydrocarbons had been detected on Titan. Radio and infrared observations from Voyager 1 showed that Titan's thick atmosphere was roughly 90% nitrogen, plus the inert gas argon (at most 1%), and methane (a few percent). On Earth, methane is found bubbling out of marshes or swamps. Voyager 1 also determined that Titan's atmosphere is nearly 10 times deeper than Earth's atmosphere. At Titan's surface, the atmospheric pressure is about 60% higher than that of Earth.
V. No Voyager or Pioneer
Could penetrate the haze
And make the surface features clear,
So now Cassini plays.
F A C T S
1. Voyager and Pioneer were spacecraft that visited the Saturn system.
2. These spacecraft could not see through the haze in Titan's atmosphere to discern the surface features.
3. Cassini now comes "into play" with greater capabilities than the earlier spacecraft.
S U P P O R T I N G - N O T E S
- The dates of the Saturn flybys of the earlier spacecraft are: Pioneer 11 in 1979, Voyager 1 in 1980, and Voyager 2 in 1981.
- Despite Voyager 1's close pass to Titan, the moon's surface features remained a mystery because spacecraft instruments could not see through Titan's thick haze. Scientists think this uniform haze layer is similar to the smog
found over many cities on Earth.
- "Voyager" and "Pioneer" lend themselves to a play on words, suggesting that even these hearty explorers could not reveal the mysterious surface beneath Titan's haze - now there is the promise of Cassini. We are primed to anticipate what the Cassini mission might be able to do.
VI. Equipped with fancy radar "eyes"
We hope Cassini sees
The Titanscape o'er which it flies,
So veiled for centuries.
F A C T S
1. Cassini is equipped with a radar imager that will be able to see through haze to measure the surface features of Titan.
2. "So veiled for centuries" signifies that although the moon was discovered more than three centuries ago, we have not had a chance to "see" Titan's surface until now. (Huygens discovered Titan in 1655, the Cassini- Huygens spacecraft arrives at Saturn and Titan in 2004 - 349 years later).
S U P P O R T I N G - N O T E S
- Cassini's radar instrument is similar to the one used by the Magellan spacecraft in the early 1990s to peer through the thick clouds of Venus and map the surface terrain. Radar does not see like the human eye, but sends out radio
