Planetarium Visit 3 – Our Planets

Role Dialog
 Narrator  Vanessa, a high school teacher, is taking her astronomy class on a field trip to a local planetarium to attend a show about the planets in our solar system.  It is an exclusive showing, meaning that the planetarium show has been reserved for her class only and for no one else that afternoon.  A school bus has just dropped her and her class off at the front door of the planetarium.
Vanessa Okay, class, the door is open so go on in and find a seat.  Remember to silence your cell phones so we don’t interrupt the show once it starts.
Narrator The twenty students in her class shuffle into the planetarium and sit in small groups scattered throughout the viewing room.  Once they are all seated, Vanessa motions to the planetarium guide to begin.  She takes her seat after doing so.
Guide Welcome to our planetarium show titled “The Planets of Our Solar System”.  This presentation will give a brief overview of the original nine planets that make up our solar system.  Has anyone here never been to a planetarium before?  (A few hands are raised.)
Guide Okay, then you folks are in for a real treat!
 Narrator The guide sits down at his console.  Soon afterward, the lights slowly dim, and the room fades into blackness.  Then the ceiling illuminates with an image of the sun and the nine planets of our solar system in proper sequence from the sun.
 Guide These are our original nine planets shown in order and sized to scale.
Dave Sir, why do you keep saying the “original” nine planets?
Guide Good question.  Does anyone know why I make this distinction?
Sally I know!  In 2006, the definition of a “planet” was changed, and Pluto was no longer considered a “full” planet.  Now we call it a “dwarf planet”, so it has lost its former  standing in the solar system.
Guide Excellent explanation!  Because I was raised with the original nine planets, that’s how I’m going to present them, for nostalgia’s sake.  Okay, looking at this image of the solar system, who can name the planets in order starting at the sun?
Judy I’ll try.  Mother very earnestly…  Mercury, Venus, Earth… makes jelly sandwiches… Mars, Jupiter, Saturn… under no protest… Uranus, Neptune, Pluto.
Guide Very good.  I heard you murmur that old mnemonic that we learned in school.  Bless the teachers for making our learning easier…  Alright, except for Earth perhaps, why do the planets have such strange names?
Rex Because they were named after the ancient Roman gods.
Guide Precisely.  Let’s take a look at our first planet from the sun, Mercury.  Being closest to the sun gives this planet two distinct characteristics.  It’s very hot, and it travels around the sun the fastest of all the planets.  Its “year”, as measured by one trip around the sun, is only 88 days.  Why did we name this planet Mercury?
Kate It was named after Mercury, the Messenger of the Gods.  He delivered the gods’ messages for them, so they expected him to be fast.  Because of this, his helmet and feet had wings on them to help him fly quickly across the skies.  Since Mercury the planet travels very fast like Mercury the Messenger, the planet was named after Mercury.
Guide Perfect answer, young lady.  This image of Mercury shows the names of craters in pink; you can see that it is heavily cratered.  These craters were named after artists, musicians, painters, and authors who have made outstanding or fundamental contributions to their field.  Do you recognize any of these craters’ names?

Okay, let’s move on to the second planet from the sun, Venus.  Who can tell us about Venus?

Eva  Venus was named after Venus, the Goddess of Love and Beauty, but its atmosphere is anything but (loving and beautiful).
Guide Haha.  Correct.  Venus’s atmosphere is 96% carbon dioxide (CO2) and 4% nitrogen (N2), so we couldn’t easily live there.  Its surface is hot and dry.  In fact, it is the hottest planet (462oC, 863oF) in the solar system, even hotter than Mercury though farther from the sun.  That’s because it is enshrouded by an opaque layer of highly reflective clouds of sulfuric acid, which causes a massive “greenhouse effect”.

There are two peculiar facts about Venus.  One, its “day” (243 Earth days) is longer than its “year” (225 Earth days).  Two, it rotates “backwards” (clockwise as viewed from the top) compared to most other planets.  Moreover, except for the moon, it is the brightest object in the night sky.  It even shines brighter than the brightest star in the sky, Sirius.  Thus, Venus can easily be seen with the naked eye.  Half of the year, it appears in the morning sky, and half of the year it appears in the evening sky.  Given its brightness, it is often referred to as both the “morning star” and the “evening star“.  The image below shows its surface if we could peek below its heavy cloud cover.

Guide I’m going to skip talking about the Earth since I figure you are somewhat familiar with that planet.  (There is a smattering of laughter from the class.)
Guide So that brings us to Mars, the so-called Red Planet due to the prevalence of iron oxide, or what we commonly call rust, on its surface.  Who can tell us about the planet Mars?
Frank It was named after the Roman God of War, perhaps because its reddish color reminds us of bloodshed in times of war.  Our space agency, NASA, is making plans for a manned journey to Mars by…, um, 2033, I think it is.
Guide Very good… and yes, it is by 2033 — in your lifetimes.
Guide This brings us to the fifth planet, Jupiter.  Being the largest of the planets, it is named after Jupiter, the King of the Gods.  It is a gaseous planet comprised mostly of hydrogen and helium gases, so we cannot land on its surface.  Its surface is turbulent and  stormy.  Its most distinctive feature is what astronomers call the Great Red Spot.  Like Venus, it can sometimes be seen with the naked eye.
Guide Who knows what the sixth planet from the sun is?
Gary That would be Saturn, the most beautiful planet due to its rings.  It’s named after the God of…um, Agriculture!  It’s also a gaseous planet.  Its rings are actually bands of orbiting rocks, ice particles, dust, and debris encircling the planet.  Saturn has a pale yellow hue due to ammonia crystals in its upper atmosphere, and it has a prominent ring system that consists of nine continuous main rings and three discontinuous arcs.  Its atmosphere is 96% hydrogen gas and 4% helium gas.  Oh, yes, there is one thing weird about it.  Its north pole is shaped like a hexagon, and scientists aren’t sure why.  And it has over 60 moons!
The hexagonally-shaped north pole region of Saturn
 Vanessa As you can see, Gary is the astronomy buff in our class.  (The class laughs lightly.)
 Guide That’s wonderful!  Gary, can you tell us about our next planet then?
Gary Sure!  After Saturn, we come to Uranus, sometimes called the Blue Planet.  It’s rocky and cold.  It was named after Uranus, the God of the Sky.  Uranus is a gas giant like Jupiter and Saturn but because it has a lot of frozen “ice” made of water, ammonia, and methane, in addition to hydrogen and helium, scientists like to call it an ice giant instead of a gas giant for this reason.  Its surface is smooth and featureless.
 Narrator A student named Marissa raises her hand.
Marissa Can I tell you about Neptune?  I did a project on that planet last year.
Guide Please, go ahead.
Marissa As Gary said about Uranus, Neptune is also classified as an ice giant.  It was named after Neptune, the Roman God of the Ocean.  Traces of methane gas in its outer atmosphere gives it a bluish appearance.  Unlike Uranus’s featureless surface, Neptune has visible weather patterns.  It has the highest wind velocities in the solar system — as high as 2,100 kilometers per hour or 1,300 miles per hour.  Similar to Jupiter, Neptune has an area known as the Great Dark Spot.
Guide Very good.  And lastly, we conclude with poor little icy, rocky Pluto, named after the God of the Underworld.  Its primary surface feature is a “heart-shaped” area of land.  It has five moons named Charon, Styx, Nix, Kerberos, and Hydra.  As we mentioned earlier, it is currently not considered to be a full-fledged planet but only a minor planet now.
Vanessa Okay, students, there will be a quiz tomorrow on these nine planets.  Know at least one unique fact about each one.  I hope you took some good notes today.
Narrator A collective groan ripples across the class.
Guide That concludes our show.  I hope you enjoyed it and please come again!
Narrator The class exits the planetarium, boards their school bus, and heads back to school to finish out the school day.



  1. New things:

    1. I didn’t expect that it’s that hot on Venus !

    2. I never heard before about that hexagonal north pole region

    3. I supposed that Saturn’s ring is not intermittent.

  2. Venus has the ultimate “greenhouse effect” due to a heavy, continuous cloud cover.

    Most of Saturns rings are continuous (unbroken) but apparently a few are broken (arcs).  (I didn’t know about the broken rings.)

  3. What a great lesson! Thank you very much! 

    I’ll try.  Mother very earnestly…  Mercury, Venus, Earth… makes jelly sandwiches… Mars, Jupiter, Saturn… under no protest… Uranus, Neptune, Pluto.

  4. I didn’t understand why “One Venus’s “day” (243 Earth days) is longer than its “year” (225 Earth days).” Because it rotates backwards? 
    I didn’t understand what is the red spot on Jupiter. So, I opened Wikipedia and read: “The oval object rotates counterclockwise, with a period of about six Earth days or 14 Jovian days. The Great Red Spot’s dimensions are 24–40,000 km west to east and 12–14,000 km south to north. It is large enough to contain two or three planets the size of Earth. It is not known exactly what causes the Great Red Spot’s reddish color. Theories supported by laboratory experiments suppose that the color may be caused by complex organic molecules, red phosphorus, or yet another sulphur compound, but a consensus has yet to be reached.”
    The information about the velocity of winds on Neptune blew me away! 2,100 kilometers per hour!

  5. The day longevity and the year are not really related. It’s two different rotations.

    Imagine you are in car moving by circle road – it’s your year.

    Inside the car you are rotating the sphere by your hands – it’s your day.

    It’s possible that day lasts for two years for instance.

  6.  What I remember:
    Mercury: has the shortest orbital period around the sun
    Venus: named after the goddess of love but it is hot
    Earth: home sweet home
    Mars: a red planet named after the god of war
    Jupiter: the biggest planet in the solar system, mostly made of gas
    Saturn: has several rings composed of rocks, 60 moons and hexagon-shaped north pole
    Uranus: has the color of sky, also made of gas but the surface is icy
    Neptune: also has icy surface, has dark blue color
    Pluto: has a heart-shaped feature, considered a dwarf planet

  7. Lin, very good!   These are other useful and interesting facts.

    • Neptune has a Great Dark Spot.
    • Jupiter has a Great Red Spot. 
    • Venus is cloud-covered and shines very brightly at nighttime.  In fact, because it is so close, it shines brighter than the brightest star in the sky (Sirius).
  8. Irina, Venus just rotates soooooooooooooo slowly that it takes 243 Earth days for it to rotate one time on its axis.  (In other words, it almost doesn’t rotate…)

    As an interesting aside, the moon rotates at just the right speed as it circles the Earth that the same side of the moon always faces us.  We can NEVER see the “back side” of the moon from the Earth.  We can see only about 55% of the moon’s surface because of this.  Because of this, for a long time, we had a theory that aliens lived on the “dark side” of the moon and spied on us while hiding their existence from us.  When our astronauts orbited the moon decades ago and  saw the other side of the moon, we were disappointed and chagrined to learn that there were NO aliens there.  Just more moon surface.

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