Designing Curriculum and Instruction in Elementary SchoolAstronomy

The job is to prepare one or more lessons on astronomy—grades 3-5.

3rd Grade Physical Science Matter, Property and Change3.P.2 Understand the structure and properties of matter before and after change3.E.1.1 Recognize that the earth is part of a system called the solar system that includes the sun (a star), planets, and many moons and the earth is the third planet from the sun in our solar system.

http://www.ncpublicschools.org/docs/acre/standards/extended/science/3-5.pdf

Follow steps, below, that are exactly the steps to use when YOU are teaching.

Work on this assignment by yourself or in small groups if you want to. I recommend planning with others, but writing it by yourself.

Here is a format you can use to do/write out the assignment. http://people.uncw.edu/kozloffm/curriculumassignmentformat.doc

Send it to me any time you want. I will give you suggestions. You can then improve it.

It is due (email) by the 12th of December at 5:00 PM.

Here are the steps.

1. Read the materials below. a. Notice and underline or bold face fact statements. “The sun is…” b. Notice and underline or bold face lists of facts IN the text, or scattered facts that YOU bring

together and can turn into a list that makes a description. “The solar system contains the following things….”

c. Notice and underline or bold face vocabulary words/concepts to teach. Solar system, sun, planet, orbit, distance, etc.

Think of how you might teach these. Some require a verbal definition (“A solar system is…..”) plus examples. Others might be taught with a synonym (“Distance means how far one thing is from another thing.”) plus examples of distances.

d. Notice and underline or bold face rule relationships. “The farther the distance a planet is from the sun, the larger is its orbit around the sun.” “The closer a planet is to the sun, the closer it is to the heat of the sun, and so the higher its temperature.” Then give examples.

e. Notice and underline or bold face routines, such as explanations. That is, knowledge that is USED or STATED as STEPS. “Here are the four stages by which solar systems are formed. First stage…. Second stage…”

2. Now divide the material into chunks. Each chunk might be a TASK in a lesson, or might be a short lesson in a SEQUENCE OF LESSONS (a UNIT). Note that the knowledge in chunks might be scattered through the text; for example, a chunk called “Basic facts about OUR solar system.” Some facts may in one paragraph of the materials, and other facts in different paragraphs. So, when you make chunks, list WHERE the information is in the text. “Some facts are in paragraph 6; also see paragraph 12.”

3. Look over everything you might want students to learn (steps 1 and 2), and think of a FINAL PERFORMANCE and FINAL OBJECTIVES (how students will do the final performance). The final performance should include: (1) a review (e.g., students define concepts, state rules, explain the stages by which solar systems develop), and (2) a project that INTEGRATES what they learned.

4. Using the final performance (step 3) as a guide, arrange the chunks in a logical sequence leading to the final performance. Ask yourself, “What do they need to know before I teach this?” For example, before you teach a rule---“The size of an object’s orbit around the sun increases as the distance of the object increases from the sun”--- students have to know what orbit, distance, and sun mean. So, you’d teach these concepts in an earlier task in the lesson. Note: The way the materials are organized may NOT be a logical sequence. So, don’t arrange chunks the same way information is presented in the text.

5. Now write a description of the chunks, in order. For each chunk: a. Label the chunk. For instance, “Parts of solar systems.”

b. State the performance (what students will do), and the objectives (how they will do it). For example:

(1) “Students define each part of solar systems, giving complete definitions,” (2) “Given pictures of solar systems, students correctly identify the parts.”

c. List all of the knowledge that you identified to teach. What facts to make a description? What concepts/vocabulary? What rule relationships (distance/heat)? What routines (a sequence of statements that make up an explanation)?

6. Now write a script for teaching the knowledge in each chunk. Follow the guide, below.

How to Teach Each Kind of KnowledgePlease read and download http://people.uncw.edu/kozloffm/fullyscaffolded.doc

Teaching Facts Teaching Lists of Facts, Concepts, or Rules—Descriptions

Teaching Concepts with verbal definition, synonym, or examples.Use synonyms and examples when a verbal definition would contain words that are too advanced. Later, teach THOSE words and use verbal definitions.

Teaching Rules Teaching Routines

Gain attention. “Boys and girls. Eyes on me. Show me ready.”… “Yes, I love the way…” “Now you’re ready to learn!”

Frame the instruction.1. Tell what you’ll be working on. “Now we’ll…”

2. Tell what they’ll do when you are done (objective). “When we’re done, you will…”

Model. Say the fact.

Lead. [If you think they need it.]

Gain attention. “Boys and girls. Eyes on me. Show me ready.”…

“Yes, I love the way…” “Now you’re ready to learn!”

Frame the instruction.1. Tell what you’ll be working on. “Now we’ll…”

2. Tell what they’ll do when you are done (objective). “When we’re done, you will…”

Model. “Here are five (show fingers) facts about…. Get ready. “First fact (one finger)….. What is our first fact…. Yes…. Second fact (two fingers)…. What is our second fact…”Etc.

Test, “Let’s do ALL our facts about.. First fact (finger). [Hint? Partial answer?] [Repeat with all.]

Gain attention. “Boys and girls. Eyes on me. Show me ready.”…

“Yes, I love the way…” “Now you’re ready to learn!”

Frame the instruction.1. Tell what you’ll be working on. “Now we’ll…”

2. Tell what they’ll do when you are done (objective). “When we’re done, you will…”

Model. Three ways:a. Verbal definition. (1) “New word/concept---comet. What’s our new word/concept?.... Spell comet. … What’s our new word/concept?”...

(2) Tell the definition.“A comet is an icy small solar system body (genus) that sometimes has a thin, fuzzy, temporary atmosphere and

Gain attention. “Boys and girls. Eyes on me. Show me ready.”…

“Yes, I love the way…” “Now you’re ready to learn!”

Frame the instruction.1. Tell what you’ll be working on. “Now we’ll…”2. Tell what they’ll do when you are done (objective). “When we’re done, you will…”

Model. Two ways: Deductive (rule examples) and Inductive (examples rule)a. Deductive.You tell the rule about how things are connected, and then give examples of it. (deductive)

(1) Model. “Here’s a rule. The farther a solar system object is from the sun, the larger is its orbit.”

Gain attention. “Boys and girls. Eyes on me. Show me ready.”… “Yes, I love the way…” “Now you’re ready to learn!”

Frame the instruction.1. Tell what you’ll be working on. “Now we’ll explain how solar systems form. ”2. Tell what they’ll do when you are done (objective). “When we’re done, you will explain how solar systems form by saying all the stages in order.”

Model. “Boys and girls. Here are the stages by which solar systems form. [Students

Test. Students say the fact.

Later, review again, until students need no hints or punctuation (no “First” and no holding up fingers).

Please read and download http://people.uncw.edu/kozloffm/fullyscaffolded.doc

sometimes also a tail, and orbits the solar system from a few years to hundreds of thousands of years (difference from other solar system bodies).”http://en.wikipedia.org/wiki/Comet

(3) Now say/show examples, and point out the features from the definition.“This is a comet. Notice the….”

(4) Show nonexamples and point out absence of features. Then do a few more examples for contrast.

“This is NOT a comet. Notice it does NOT have…”

(5) Test all examples and nonexamples (delayed acquisition test). “Is this a comet… How do you know?” [Student use definition.]

Later, work on generalization items.

b. Synonym. (1) “New word. Orbit. What’s our new word?... Spell orbit… What’s our new word?”…

(2) Tell the new word and its synonym. “Listen, an orbit is a path shaped like a circle that one thing makes around another thing. Again, an orbit is…..”

(3) Test. “What’s another way to say a path shaped like a circle that one thing makes around another thing.”… orbit…Yes, orbit IS a path shaped like a circle that one thing makes

[repeat?]

(2) Test. “What’s our rule?” correct errors and verify.

(3) Examples. “Look here (point). Mercury is the closest planet to the sun. It’s orbit is the smallest.” [with older kids use numbers, in miles.] Earth is farther from the sun than Mercury (point and/or tell distance) and Earth’s orbit is larger than the orbit of Mercury.”

[More examples.]

(4) Test. “Jupiter is farther from the sun than Earth. Which planet has a larger orbit?.... How do you know? [students use the rule.] Correct errors and verify.

Later, work on generalization; e.g., the orbits of moons around planets.

b. Inductive. (1) Give examples.

“Boys and girls. Here are facts. Distance Orbit from sun

Merc 37 m miles 58 m milesVen 65 m miles 108 m milesEarth 93 m miles 150 m milesMars 140 m miles 228 m milesJupi 484 miles 778 m milesSatur 884m m 1427 m miles

might read from text.]

“Stage one….” [ name it and say a few things that happen.]

Test. “What is the first stage…. Tell what happens.” Correct errors and verify.

Model. “Stage two…. “[ name it and say a few things that happen.]

Test. “What is stage two…. Tell what happens.” Correct errors and verify.

Model. “Stage three….” [ name it and say a few things that happen.]

Test. “What is stage three…. Tell what happens.” Correct errors and verify.

Model. “Stage four…” [ name it and say a few things that happen.]

Test. “What is stage four…. Tell what happens.” Correct errors and verify.

Integrate.“Now let’s do all the stages

around another thing.”

(4) Examples of new word and synonym.“Listen, the car is making a path shaped like a circle around the house. I’ll say that sentence with our new word. The car is making an orbit around the house. ”

More examples.

(5) Test. “Your turn to use our new word. Listen, the moon was making a path shaped like a circle around the sun. Say that with our new word.” The moon was making an orbit around the sun. Verification.

(6) Give examples of USING the new word. “Here’s an orbit. [point.] The earth (one thing) is making a path (this circular line) around another thing—the sun…Here’s the earth’s moon (one thing) making a path (circular line) around another thing---the earth.” Etc.

(7) Give nonexamples. “This is an asteroid (one thing). It is going straight down to another thing—the earth. It is NOT making a circular path around the earth. So, it does not have an orbit.”

(8) Test all. Use the examples and nonexamples. “Is this object making an orbit?....How do you know?” Students use the idea of circular path.

Later, work on generalization items.

Uran 1786 m miles 2870 m milesNept 2790 m miles 4497 m milesPluto 3627 m miles 4914 m miles

Show solar system and give facts for each planet. Tell the rule each time.

“Earth is farther from the sun than Venus, and the orbit of the Earth is greater than the orbit of Venus.”

Have students summarize the facts by saying the rule.

(2) Test. Now give new examples—for instance,

“Moon A is 2 million miles from Jupiter, and its orbit is 5 million miles. Moon B is 4 million miles from Jupiter. Whose orbit is larger? Moon 1 and Moon 2… How do you know?” [students use the rule.]

More examples.

that explain how solar systems form… “ [Prompt students to read from their notes or from text.”

“Stage one…” Correct errors and verify.

Do all the stages.

Now all together.“Now YOU say the stages all together.” Correct errors and verify.

c. Examples and nonexamples only.

(1) “New word/concept---eliptical. What’s our new word/concept?.... Spell eliptical. … What’s our new word/concept?”...

(2) Examples. “This is elliptical.” “This is elliptical.” “This is elliptical.”

“This is NOT elliptical.”

“This is not elliptical.”

“This IS elliptical.”

(3) Test. Show all examples and nonexamples, and ask, “Is this elliptical?” Correct errors or verify.

Later, work on generalization.

Here are more resources for writing procedures, but I don’t think you’ll need them.

**** However, you MUST look at this document Seven point lesson plan http://people.uncw.edu/kozloffm/SevenPointLessonPlan.doc

We have generally been following the seven point lesson plan.

Brief procedures for teaching the six kinds of knowledge http://people.uncw.edu/kozloffm/brief%20procedures%20for%20the%20forms.doc

Teaching Factshttp://people.uncw.edu/kozloffm/sampleprocedureforteachingfactTASK.doc

Teaching List. Phases of Mitosishttp://people.uncw.edu/kozloffm/sampleprocedureforlistsMitosisTask.doc

Sample format for teaching vocabulary with synonyms http://people.uncw.edu/kozloffm/Sample%20format%20for%20teaching%20vocabulary%20by%20synonyms.doc

Sample format for teaching vocabulary with examples http://people.uncw.edu/kozloffm/Sample%20format%20for%20teaching%20vocabulary%20by%20examples.doc

Teaching Sensory Concept. On

http://people.uncw.edu/kozloffm/sampleprocedureforsensoryconceptTask.doc

Sample format for teaching vocabulary with verbal definition

http://people.uncw.edu/kozloffm/Sample%20format%20for%20teaching%20vocabulary%20by%20verbal%20definition.doc

Teaching Rule-relationship. Temperature/pressure

http://people.uncw.edu/kozloffm/procedureforRuleTemperatureandpressureLesson.doc

Teaching Routine. Sounding Out Wordshttp://people.uncw.edu/kozloffm/sampleprocedureforRoutinesoundingoutLesson.doc

7. Finally, make a set of guided notes for each chunk of the lesson or lessons

Guided Notes on Astronomy

Topic/chunk ____________________ You will learn and do….

Outline: What we will work on. List important concepts and rules.

Task 1

Task 2

Task 3

Task 4

http://www.bing.com/images/search?q=solar+system+for+kids&view=detail&id=CEAC1F2B7CA05E23E750C80A115466AC7DEA15AD&first=0

What Is The Solar System?

The Solar System is made up of all the planets that orbit our Sun. In addition to planets, the Solar System also consists of moons, comets, asteroids, minor planets, and dust and gas.

Everything in the Solar System orbits or revolves around the Sun. The Sun contains around 98% of all the material in the Solar System. The larger an object is, the more gravity it has. Because the Sun is so large, its powerful gravity attracts all the other objects in the Solar System towards it. At the same time, these objects, which are moving very rapidly, try to fly away from the Sun, outward into the emptiness of outer space. The result of the planets trying to fly away, at the same time that the Sun is trying to pull them inward is that they become trapped half-way in between. Balanced between flying towards the Sun, and escaping into space, they spend eternity orbiting around their parent star.

How Did The Solar System form?

This is an important question, and one that is difficult for scientists to understand. After all, the creation of our Solar System took place billions of years before there were any people around to witness it. Our own evolution is tied closely to the evolution of the Solar System. Thus, without understanding from where the Solar System came from, it is difficult to comprehend how mankind came to be.

Scientists believe that the Solar System evolved from a giant cloud of dust and gas. They believe that this dust and gas began to collapse under the weight of its own gravity. As it did so, the matter contained within this could begin moving in a giant circle, much like the water in a drain moves around the center of the drain in a circle.

At the center of this spinning cloud, a small star began to form. This star grew larger and larger as it collected more and more of the dust and gas that collapsed into it.

Further away from the center of this mass where the star was forming, there were smaller clumps of dust and gas that were also collapsing. The star in the center eventually ignited forming our Sun, while the smaller clumps became the planets, minor planets, moons, comets, and asteroids.

A Great Storm

Once ignited, the Sun's powerful solar winds began to blow. These winds, which are made up of atomic particles being blown outward from the Sun, slowly pushed the remaining gas and dust out of the Solar System.

With no more gas or dust, the planets, minor planets, moons, comets, and asteroids stopped growing. You may have noticed that the four inner planets are much smaller than the four outer planets. Why is that?

Because the inner planets are much closer to the Sun, they are located where the solar winds are stronger. As a result, the dust and gas from the inner Solar System was blown away much more quickly than it was from the outer Solar System. This gave the planets of the inner Solar System less time to grow.

Another important difference is that the outer planets are largely made of gas and water, while the inner planets are made up almost entirely of rock and dust. This is also a result of the solar winds. As the outer planets grew larger, their gravity had time to accumulate massive amounts of gas, water, as well as dust.

The Solar System Has Over 100 objects

It is true that there are only eight planets. However, the Solar System is made up of over 100 worlds that are every bit as fascinating. Some of these minor planets, and moons are actually larger than the planet Mercury!

Others, such as Io, have active volcanoes. Europa has a liquid water ocean, while Titan has lakes, rivers, and oceans of liquid Methane. You can read more about these amazing worlds by clicking here.

The Asteroid Belt, The Kuiper Belt, And The Oort Cloud

You have probably heard about the Asteroid Belt. This band of asteroids sits between the orbits of the planets Jupiter and Mars. It is made up of thousands of objects too small to be considered planets. Some of them no larger than a grain of dust, while others, like Eros can be more than 100 miles across. A few, like Ida, even have their own moons.

Further out, beyond the orbit of the minor planet Pluto, sits another belt known as the Kuiper Belt. Like the Asteroid Belt, the Kuiper Belt is also made up of thousands, possibly even millions of objects too small to be considered planets. A few of these objects, like Pluto, are large enough that their gravity has pulled them into a sphere shape.

These objects are made out of mostly frozen gas with small amounts of dust. They are often called dirty snowballs. However, you probably know them by their other name... comets.

Every once in a while one of these comets will be thrown off of its orbit in the Kuiper Belt and hurled towards the inner Solar System where it slowly melts in a fantastic show of tail and light.

Beyond the Kuiper Belt sits a vast area known as the Oort Cloud. Here within this jumbled disorganized cloud live millions of additional comets. These comets do not orbit the Sun in a ring or belt. Instead, each one buzzes around in a completely random direction, and at extremely high velocities.

Beyond The Oort Cloud

The Sun's solar winds continue pushing outward until they finally begin to mix into the interstellar medium, becoming lost with the winds from other stars. This creates a sort of bubble called the Heliosphere. Scientists define the boundaries of the Solar System as being the border of the Heliosphere, or at the place where the solar winds from the Sun mix with the winds from other stars.

The Heliosphere extends out from the Sun to a distance of about 15 billion miles, which is more than 160 times further from the Sun than is the

The Sun's Name Means:The Romans called the sun Sol, which in English means sun. In ancient Greece, the sun was called Helios.

Light from the Sun can reach the Earth in only 8 minutes! This is called the speed of light. The Sun is nearly 93 million miles (approx 145 million km) from Earth.

Our Sun is not unique in the universe. It is a common middle-sized yellow star which scientists have named Sol, after the ancient Roman name. This is why our system of planets is called the Solar System. There are trillions of other stars in the universe just like it. Many of these stars have their own systems of planets, moons, asteroids, and comets.

The Sun was born in a vast cloud of gas and dust around 5 billion years ago. Indeed, these vast nebulae are the birth places of all stars. Over a period of many millions of years, this gas and dust began to fall into a common center under the force of its own gravity.

At the center, an ever growing body of mass was forming. As the matter fell inward, it generated a tremendous amount of heat and pressure. As it grew, the baby Sun became hotter and hotter. Eventually, when it reached a temperature of around 1 million degrees, its core ignited, causing it to begin nuclear fusion.

When this happened, the Sun began producing its own light, heat, and energy.

What is Thermonuclear Fusion?

Thermonuclear fusion is the process in which a star produce its light, heat, and energy. This happens at the core of the star. The core is superheated to millions of degrees. This heat travels towards the surface and radiates out into the universe. Through this thermonuclear process, stars "burn" a fuel known as hydrogen. The result is that they create another type of fuel known as helium. However, stars do not burn in the same way that a fire does, because stars are not on fire.

Convection

Heat rises, while cooler gas falls. Have you ever noticed that your basement is always much cooler than upstairs. The same laws of physics apply within stars. Because heat rises while

cooler gases fall, the gas within a star is constantly rising and falling. This creates massive streams of circular motion within the star. This is called convection.

As the gases near the core of the Sun are heated, they begin to rise towards the surface. As they do so, they cool somewhat. Eventually they become cool enough that they begin to sink back down towards the core. It can take an atom millions of years to complete one complete cycle around a convection stream. As a result of this process, the temperature on the surface of the Sun is around 10,000 degrees Fahrenheit, which is much cooler than its superheated core.

Sun Spots

We don't often think of the Sun as having cooler areas on its surface. The Sun is far too hot for an astronaut to ever visit, but there are areas which are slightly cooler than others. These areas are known as sun spots. Sun spots are still very hot. However, because they are slightly cooler than the rest of the surface of the Sun, they appear slightly darker in color. The gravitational forces in Sun spots are also stronger than the other hotter areas. Of course, you cannot look directly at the Sun to see these spots because you would damage your eyes. Astronomers have to use special telescopes with filters and other instruments to be able to see the cooler spots on the surface of the Sun.

Sun spots come and go on a regular basis. At times, there are very few, if any sun spots. At other times there are far more. They generally increase in intensity and then decrease over a period of 11 years. This 11 year cycle is known as the Saros Cycle.  To learn more, click here.

Solar Flares

During periods of high solar activity, the Sun commonly releases massive amounts of gas and plasma into its atmosphere. These ejections are known as solar flares. Some solar flares can be truly massive, and contain impressive power. On occasion, these more powerful flares can even cause satellites orbiting the Earth to malfunction. They can also interact with Earth's magnetic field to create impressive and beautiful light shows known as the Northern and Southern lights. In the northern hemisphere, these lights are commonly known as the Aurora Borealis.

Solar Winds

As the Sun burns hydrogen at its core, it releases vast amounts of atomic particles, or pieces of atoms, into outer space. These atomic particles along with the Sun's radiation create a sort of wind, known as the solar wind.

This wind blows particles outward in all directions from the Sun. Even as you read this, there are atomic particles which are traveling from the Sun towards you. Often, particles pass right through your body without you ever realizing it.

Eventually this wind reaches out beyond the Solar System and begins to mix with the winds from other stars. The bubble around the Sun where the solar winds are still strong enough to blow outward is known as the heliosphere (note the Greek name Helios). The area of space where the winds are too weak to continue pushing outward and instead begin to mix with the winds of other stars is known as the interstellar medium.

The Sun's Family

The Sun is by far the largest object in the Solar System. 98% of all matter within the Solar System is found within the Sun. This means that all the planets, moons, asteroids, minor planets, comets, gas, and dust would all combine to make up only 2% of all the matter in the Solar System. The Sun is so large that the Earth could easily fit inside the Sun a million times.Because the Sun is so large compared to everything else, it is easily able to hold on to the rest of the matter, causing everything else to orbit around it.

Mercury means:In astronomy mythology, Mercury was the Roman version of the Greek god Hermes. He was the messenger for the other gods, and for this reason Mercury is often depicted in pictures with winged sandals. In addition to delivering messages, he was also the protector of travelers and merchants.

How much would you weigh on Mercury? If you moved to Mercury you would not weigh as much as you do on Earth. Not because you would lose weight on the spaceship, but because Mercury is smaller, and so has less gravity. If you weigh 70 pounds (32 kg) on Earth, you would weigh only about 27 pounds (12 kg) on Mercury.

The Planet The planet Mercury is the closest of the planets to the Sun. Because this planet lies so close to the Sun, and as a result somewhat near to Earth, it is visible to observers on Earth in the late

evening or early morning sky. Because of this, Mercury has become a part of the mythology and legend of almost every culture throughout the history of the Earth.

This planet is often called a morning star. This is because Mercury shines brightly in the early morning just before the sun rises. It has also been called an evening star for the same reason. Mercury is often visible for a brief period of time just after the Sun sets.

Mercury is Heavy Because of its proximity to the Sun, Mercury's evolution took a slightly different course than that of the other planets. As the Sun formed, it pushed much of the lighter gas and dust out of the inner Solar System, leaving behind only heavier elements. As a result, Mercury is made out of a large percentage of heavier elements, mainly iron. It is essentially a large metal ball of iron with a very thin silicate crust. Mercury's core makes up about 75% of the planet. Its thin mantle, or crust, is only about 300 to 400 miles thick (500 to 600 km). Next to Earth, Mercury is the second most dense planet in our Solar System.

Mercury Has Wrinkles As Mercury's iron core cooled it contracted, or shrunk. This caused its rocky crust to become wrinkled. Scientists call these wrinkles Lobate Scarps. This scarps can be hundreds of miles long and even up to a mile high. Mercury's core has not cooled completely, however. Researcher recently found evidence that Mercury has a molten core.

Mercury is ScarredThe surface of the planet Mercury is covered with craters. These craters have been created by eons of accidental encounters with asteroids and comets. All celestial bodies within the Solar System are subject to these bombardments. However, many of the planets have the ability to heal themselves through natural geological processes.

Because Mercury's crust is so thick and hard, no volcanic activity can make its way through to the surface of the planet. Since this surface volcanic activity cannot happen, Mercury will forever retain its scars.

Mercury Has No Atmosphere The planet Mercury is too small and has too little gravity to hold onto an atmosphere. Any gases released from the planet quickly escape into space. Also, Mercury is so close to the Sun that any atmosphere is quickly blown away by the Sun's solar winds. That means that there is almost no air on Mercury.

Temperature ExtremesMercury is just a little bit larger than Earth's moon. The surface of Mercury that faces the Sun can reach about 800 degrees Fahrenheit. On the other hand, the temperature on the nighttime side can plummet to almost -300 degrees Fahrenheit. This is because Mercury has little to no atmosphere to help regulate temperature.

Time on Mercury Because of its close location to the Sun, the planet Mercury has become tidally locked to the

Sun, or nearly so. The tidal forces of the Sun have over eons of time slowed down the rotation of Mercury to match its revolution around the Sun. The result is that Mercury rotates very slowly. One day on Mercury is about 58-1/2 Earth days long. But while Mercury's days are very long, its revolution around the Sun is rather fast. Mercury can complete one orbit around the Sun in only 88 Earth days. That's just about 3 months here on Earth. This is why Mercury's name is so appropriate. In mythology, Mercury was a speedy messenger, just like the planet's speedy revolution around the Sun.

Moons: Mercury has no moons.

Mercury's orbit is not a perfect circle like most of the other planets. It's actually egg-shaped. At times, Mercury's orbit brings it closer to the Sun than other times, while all the other planets that have circular orbits are always the same distance from the Sun.

Venus means:In astronomy mythology, Venus was the Roman goddess of love and beauty. In Greek, her name was Aphrodite.

How much would you weigh on Venus? Because Venus and the Earth are almost the exact same size, you would weigh almost exactly the same on either planet. If you weighed 70 pounds (32 kg) on Earth, you would weigh 63 pounds (29 kg ) on Venus.

The PlanetThe planet Venus has long been one of the most misunderstood of all the inner planets. Like the Earth, Venus has an atmosphere. However, Venus' atmosphere is far thicker than that of the Earth, making it difficult for modern science to penetrate. Interestingly, scientists have recently been able to peek through the thick clouds and get a few glimpses of the surface. There are numerous volcanoes and many mountains that appear misshapen.

There is much we still do not know about how this planet looks and what it is like. However, using special instruments and probes scientists have in recent years unlocked many of the secrets long hidden by this mysterious world. In the 1970s, the Soviet Union actually was able to land more than one probe on the surface of Venus. These scientific probes only lasted a few hours before they were destroyed by the intense heat of the planet. These probes were able to take several pictures and send them back to earth for scientists to study.

The Earth Has a Sister Venus is in many ways Earth's sister planet. It is almost identical in size, chemistry, gravity and density as the Earth. In other words, Venus is made up of almost the exact same types of

materials as the Earth and in about the same amounts. Venus has volcanoes, mountains and sand, just like Earth.

However, if they are twins, then Venus is the evil twin; she is the Earth gone wrong, very wrong. Venus is a deadly world where the surface temperature is hot enough to cook a meal in mere minutes. There is nowhere to hide from this ever present furnace. And with the atmosphere containing mostly carbon dioxide, it makes Venus a highly toxic place. No living thing would ever be able to survive on Venus.

Global WarmingIn the early days of Venus' 4 billion year long life, it would have appeared very similar to the Earth. The two would have been almost identical. However, over a period of a few million years, forces on Venus caused it to take a very different course than the Earth.

Venus lies much closer to the Sun than does our planet. That single fact has caused an unstoppable chain of events that doomed Venus to its fiery existence. Owing to its closer proximity to the Sun, Venus' temperature should have been only slightly warmer than that of the Earth. But as the planet warmed, the water evaporated. This increase in water vapor in the atmosphere began a cycle of global warming that could not be stopped. Water vapor is a very effective greenhouse gas. (Greenhouse gas soaks up hot air and prevents it from escaping into space). The increase in water vapor caused the temperature to rise further, which caused more water to evaporate, causing the temperature to climb still further.

Today it is likely that all of Venus' water has evaporated into the atmosphere. This atmosphere effectively traps the Sun's energy causing the surface to burn much hotter than it naturally would. The temperatures on Venus can reach almost 900 degrees Fahrenheit (approx 482 degrees Celsius).

Venus is Dry The Earth has a protective layer known as the Ozone Layer. This important shield protects the Earth from the Sun's ultraviolet radiation. Venus does not have an ozone layer. As a result, the ultraviolet radiation from the Sun finds its way directly into Venus' atmosphere. Over many billions of years this radiation has slowly broken down water molecules into hydrogen and oxygen. As a result, there is today very little water left on Venus.

GeographyVenus has many, many volcanoes. We don't know for sure, but it is possible that Venus has more volcanoes than any of the other planets in our Solar System. But unlike the volcanoes on Earth that can sometimes erupt in an explosive manner, the volcanoes on Venus are believed to erupt in a less violent way. In fact, it is believed that they don't erupt at all. Instead, it is thought that the lava just slowly flows out onto the surface.

Venus has a few mountainous areas along with extensive flat areas. There are craters and evidence that the surface long ago moved, much like the surface of the Earth moves today. But unlike the Earth's surface, there is no evidence that Venus has a tectonic plate system.

From West to East If you somehow found a way to survive the scorching heat found on the surface of Venus, you would quickly notice something strange about the days. Aside from the fact that Venus rotates very slowly so that a day on Venus lasts more than 100 Earth days, Venus also rotates in the opposite direction as almost all the other planets.

Instead of the Sun rising in the east and setting in the west, the Sun on Venus would appear to rise in the west and set in the east.

Moons: Venus has no moons.

Earth means:In astronomy mythology, her Greek name was Gaea. Earth was the mother of the mountains, valleys, streams and all other land formations. She was married to Uranus.

How Big is the Earth? The Earth is the biggest of all the terrestrial planets. A terrestrial planet is a dense planet found in the inner Solar System. The diameter of Earth is 7,926 miles. The circumference measured around the equator is 24,901 miles. There are currently almost 7 billion people living on the Earth. About 30% of the Earth's surface is covered with land, while about 70% is covered by oceans.

The PlanetOur planet is  an oasis of life in an otherwise desolate universe.  The Earth's temperature, weather, atmosphere and many other factors are just right to keep us alive.

To learn more about Earth, please visit our Earth Sciences website.

Moons: The Earth has one moon.  Its name is Luna.  To learn about Luna Click Here.

How Big is the Earth? The Earth is the biggest of all the terrestrial planets. A terrestrial planet is a dense planet found in the inner Solar System. The diameter of Earth is 7,926 miles. The circumference measured around the

equator is 24,901 miles. There are currently almost 7 billion people living on the Earth. About 30% of the Earth's surface is covered with land, while about 70% is covered by oceans.

Moons: The Earth has one moon. Its name is Luna. To learn about Luna

Luna is a beautiful world that lies some 384,400 kilometers (almost 239,000 miles) from Earth. It is littered with mountains, valleys, old volcano sites, and many bowl-like holes called craters. Luna is a neat world to explore because you can see it without a telescope or binoculars. I know you have seen it. In fact, you may even see it tonight, that is because Luna is our moon.

Search The Totally Free Children's Learning Network

Astronomy | Biology | Dinosaurs | Geology | Geograpy | History | Math | Memory | Miamiopia | SpellingTry Miamiopia, Our New Free Educational Virtual World

The Earth's Moon

Luna is a beautiful world that lies some 384,400 kilometers (almost 239,000 miles) from Earth. It is littered with mountains, valleys, old volcano sites, and many bowl-like holes called craters. Luna is a neat world to explore because you can see it without a telescope or binoculars. I know you have seen it. In fact, you may even see it tonight, that is because Luna is our moon.

For thousands of years, this fascinating place has been written about in stories and poems, sung about in songs, and been included in folklore and legends. But, did you know that our moon has some very important functions? The moon regulates the ocean tides on Earth. It also keeps the Earth's tilt on its axis regular. This is why we have seasons here on Earth. When the North Pole is tilted towards the sun, then the Northern Hemisphere is in its warmer seasons, like summer, and the Southern Hemisphere is in its colder seasons. When the South Pole is tilted towards the sun, then the Southern Hemisphere has its warmer seasons and the Northern Hemisphere is colder. The tilting of the Earth on its axis is also known as Earth's wobble on its axis.

As you observe the moon from your back yard, you will probably notice right away that some areas are darker than others. This is because long ago there were many comets and asteroids, many more than today, which frequently hit the worlds of our Solar System. Every once in a while, a very large object would crash into the Moon hard enough to break through its surface rock causing lava to ooze out. When you see a dark area, you are looking at an ancient bed of lava rock from one of these impacts. If a large object struck the Moon today, it would not cause a volcano, however. This is because the core of the Moon has almost completely cooled down, meaning there is no longer any lava in the core to ooze from its rock surface. The lighter areas on the surface of the moon are where objects have crashed into the surface more recently. But recently in astronomy terms can mean a million years ago. In photographs of the Moon, you can see large scars called craters. Craters are caused by collisions between the Moon and other objects, such as asteroids or comets.

The moon has been explored many times in the last half century. You probably know that astronauts landed on the Moon in 1969. But did you know that this was not the first successful contact humans made with the moon? And did you know that astronauts landed on the moon more than once? It's true!

In 1959, the Soviet Union launched a probe, called Luna 1, into space that was supposed to crash into the surface of the Moon to study the soil and radiation in space. This probe unfortunately malfunctioned and it missed hitting the Moon. Instead, it flew past the Moon and into space. Contact with this probe was lost as it flew away into space. Later that same year, the Soviet Union was successful in landing a probe on the Moon, Luna 2. This

probe had sensors on board that allowed scientists back on Earth to study interplanetary space and sodium gas. Luna 2 made history because it was the first man-made object to make contact with another object in space.

Following this, more probes and satellites were sent to the Moon by the U.S. and Soviet Union. Some impacted the surface like Luna 2, some landed softly on the Moon, and others simply orbited the Moon and mapped out possible landing sites for future missions.

Then, on July 20, 1969, American astronauts landed on the surface of the Moon in a spacecraft named the Apollo 11. Neil Armstrong was the first human being to step onto the surface of the Moon. This mission was followed by 5 more successful missions to land on the Moon. In total, 12 astronauts walked on the surface of the Moon from 1969 to 1972. The astronauts collected 382 kg (842 pounds) of rock samples from the moon during these missions. They conducted many scientific experiments also, including solar wind experiments, soil, magnetic field experiments, and many others. They were also able to travel around on the surface of the Moon in a rover vehicle that kind of looked like a dune buggy.

Many scientists consider the Earth and Luna, or Moon, to be a double planet system. This is because they are so close in size.

Mars means: Mars was the Roman god of war and agriculture. It may not seem like these two things go together, but they do. Mars protected those who fought for their communities, and stayed home to raise crops for food. In Greek, Mars was known as Ares.

How much would you weigh on Mars? If you weighed 70 pounds (32 kg) on the Earth, you would weigh about 27 pounds (12 kg) on Mars.

The PlanetMars excites scientists because its mild temperament is more like the Earth's than any of the other planets. Evidence suggests that Mars once had rivers, streams, lakes, and even an ocean. As Mars' atmosphere slowly depleted into outer space, the surface water began to permanently evaporate. Today the only water on Mars in either frozen in the polar caps or underground.

You may sometimes hear Mars referred to as the "Red Planet." This is because the surface of Mars is red. If you stood on the surface of Mars, you would see red dirt and rocks everywhere.

ExplorationAt first, the only way modern explorers could study Mars was with satellites that would fly close

to the surface of Mars and take pictures as it did so. The satellites would then send these pictures back to Earth.

As scientific technology became more advanced, scientists were able to put spacecraft into orbit around the Red Planet. These types of missions allowed scientists and researchers to obtain even more information about Mars.

Then, as technology advanced even more, scientists and researchers were able to actually land spacecraft on the surface of Mars. To learn more about these amazing explorations

Moons: Mars has two moons, their names are Deimos and Phobos

Deimos and Phobos These two odd shaped worlds are the moons of the planet Mars. They are extremely small, only 12.6 km (7.8 miles) and 22.2 km (13.7 miles), respectively. That is smaller than most towns. Their small size causes their gravity to be very weak. Because of this weak gravity they do not have enough force to pull themselves into a round shape. It is thought that these two worlds probably started as asteroids between Mars and Jupiter. However, the powerful gravity of Jupiter probably flung them out near Mars where they were captured eternally by the small red planet. 

Phobos (to the right) is a doomed world. Those who live in about 50 million years will never get to see it. Every hundred years it moves almost two meters closer to the surface of Mars. Eventually it will either crash into the planet or be ripped apart, forming a ring like the rings around the outer planets.

Mars has higher mountains, and deeper canyons than any other planet. The largest canyon on Mars would stretch from New York City to Los Angeles on the Earth. That makes the Grand Canyon look tiny. It also has the Solar System's biggest volcano, Olympus Mons, which is nearly 3 times larger than Mount Everest.Jupiter means: Jupiter, known as Zeus in Greek mythology, over threw his father Saturn to become king of the gods. He then split the universe with his brothers Neptune and Pluto.

How much would you weigh on Jupiter? If you traveled to Jupiter on vacation, you would be very heavy. If you weigh 70 pounds (32 kg) on Earth, on Jupiter you would weigh 185 pounds (84 kg). This is because Jupiter is such a large planet and so has more gravity.

The PlanetJupiter is by far the largest planet in our Solar System. The Earth could fit inside Jupiter more than 1000 times.

Jupiter is a very stormy planet. There are storms found throughout the atmosphere, and most of the storms seem to never end. The many different cloud formations and storms in the atmosphere also make Jupiter a very colorful planet.

Jupiter's great red spot, visible in the picture above to the right, is where a giant storm has been raging for at least 300 years. This red spot is also called "The Eye of Jupiter" because of its shape. This storm's super hurricane winds blow across an area larger than the Earth.

Jupiter is considered a gas giant because it does not have a solid surface. Under its atmosphere is a large liquid ocean of hydrogen and water. What lies in between that ocean and the atmosphere? Actually, there is no in between. The atmosphere slowly gets thicker and thicker until it becomes part of the ocean. In other words, Jupiter's ocean has no surface on which you could float a boat. The sky becomes the ocean.

RingsDid you know Jupiter has rings? They are faint and are only able to be viewed when Jupiter passes in front of the Sun. This is because the light from the Sun lights them up for us to see here on Earth. There are three rings in all. They are named Gossamer, Main and Halo.

Moons: Jupiter has 50 official moons and 12 provisional (unofficial) moons. The four largest and most well-known were discovered by Galileo in the year 1610. Their names are Io, Europa, Ganymede and Callisto. Some of the other moons are Adrastea, Ananke, Carme, Elara, Himalia, Leda, Lysithea, Metis, Pasiphae, Sinope, and Thebe.

Inner Moons

These four worlds are the closest known moons to the surface of the planet Jupiter.  For this reason they are called the Inner Moons. 

Metis

This moon was discovered by Stephen Synnott in 1979.  In ancient mythology, Metis was a Titaness who was the first wife of Jupiter.  Metis is the closest moon to the surface of Jupiter and can be found with in the planet's main ring. 

This moon is probably an asteroid that got caught by Jupiter's immense gravity. 

Adrastea

Adrastea was discovered in 1979 by David Jewitt.  In mythology, Adrastea was the god who passed out rewards and punishments, she was also the daughter of Jupiter.  This moon is the second closest moon to the surface of Jupiter.

Adrastea is probably an asteroid that got caught by Jupiter's immense gravity. 

Amalthea

Amalthea was discovered by Edward Emerson Barnard in 1892.  Amalthea nursed Jupiter as a young baby using goat's milk.   Amalthea is the third closest moon to the surface of Jupiter.

This moon is probably an asteroid that got caught by Jupiter's immense gravity. 

Thebe

The moon Thebe was discovered by Stephen Synnott in 1979.  It was named after a nymph, daughter of the river god Asopus.  Thebe is the fourth known moon from the surface of Jupiter.  It too was probably and asteroid at one time. 

Galilean moons

In the early 1600's, an Astronomer named Galileo Galilei looked at the sky for the first time using a telescope.  He was the first scientist to ever use a telescope to study outer space.  When he looked at Jupiter, he discovered four moons.  Today we know that Jupiter actually has at least 62 moons.  Only four of its moons are big enough to be seen through the small type of telescope that Galileo was using.  Today we call these four large moons the Galilean moons. 

Io

Io is a very violent place where a human would not live long enough to enjoy the beautiful colors it contains in its land formations.

Io lies within a dangerous part of Jupiter's magnetic field.  The radiation found in this area is a thousand times stronger than what is needed to kill a Human. If you somehow survived the radiation you would still be in trouble because Io is covered with giant volcanoes which erupt with extreme frequency. These volcanoes spurt out large amounts of sulfuric acid into the air which falls, causing the beautiful reds, yellows and oranges of Io's appearance.

Io is the third largest of Jupiter's moons, and slightly larger than the Earth's moon.  It was named after a woman whom Jupiter fell in love with. 

Europa

Europa is a cold, smooth, ice covered world. A long time ago in space there was a period of time when it was very common for asteroids and comets to hit other worlds. This is called the Heavy Bombardment Period. During this time most worlds, including Earth, were scarred with bowl shaped impressions called craters. Most worlds remain scarred today. However, some, like the Earth, have since recovered their surfaces with new rock lava or ice, hiding these scars.

Because Europa is smooth, we know it too has recovered its surface since the Heavy Bombardment Period. This, along with a few other clues, has led scientists to believe that beneath its icy outer shell lies a liquid water ocean heated by Europa's hot core. This makes Europa the most likely place for life to exist outside of the Earth.

Europa was named after a Phoenician princess abducted to Crete by Zeus.

Read more about Europa

Ganymede

Like Europa, it has recently been discovered that Ganymede probably has a liquid water ocean underneath its icy exterior.  Ganymede is the largest of Jupiter's moons.  It is larger in diameter than both the planets Mercury and Pluto. 

Ganymede was named after a very handsome Trojan boy who Zeus took away to be the cup bearer for the gods.

Callisto

Callisto is the eighth moon from the surface of Jupiter, and the second largest.  This moon was named after a nymph, loved by Zeus but hated by Hera. Hera changed her into a bear, Zeus then placed her in the sky as the constellation Ursa Major. 

Callisto is almost the same size as the planet Mercury.  

Outer Moons

The following are the outer moons.  They are the furthest moons from the surface of the planet Jupiter. 

Leda

Leda is the ninth moon from the surface of Jupiter.  This

world is also the smallest of Jupiter's moons.  It was discovered by Charles Kowal in 1974.  The name "Leda" comes from a queen of Sparta and the mother, by Zeus in the form of a swan, of Pollux and Helen of Troy. 

This moon was almost certainly an asteroid at one time.

Himalia

Himalia is the tenth moon from the surface of Jupiter.  It was discovered by Charles Perrine in 1904.  Himalia was named after a nymph who bore three sons of Jupiter. 

Lysithea

The eleventh moon from Jupiter's surface is Lysithea.  In ancient mythology, she was the daughter of Oceanus.  Lysithea was discovered in 1938 by Seth Nicholson. 

Sorry no pictures available

Elara

Elara was discovered by Charles Perinne in 1905, and is the twelfth moon from Jupiter's surface.  It is named after the mother by Zeus of the giant Tityus.

Sorry no pictures available

Ananke

The thirteenth moon from Jupiter was discovered in

Sorry no pictures available

1951 by Seth Nicholson.  Ananke is named for the mother of Adrastea, by Jupiter.

Carme

Carme is Jupiter's fourteenth moon.  It was discovered in 1938 by Charles Nicholson.  Carme was the mother, by Zeus, of Britomartis, a Cretan goddess.

Sorry no pictures available

Pasiphae

Jupiter's fifteenth moon, Pasiphae, was discovered by P. Melotte in 1908.  Pasiphae was the wife of Minos and mother, by a white bull, of the Minotaur

Sorry no pictures available

Sinope

Sinope is Jupiter's sixteenth moon.  It was discovered by Seth Nicholson in 1914.  Sinope was a woman who was courted unsuccessfully by

Saturn means: Saturn was the Roman god of agriculture. He was called Cronus by the Greeks. He is the son of Uranus and the father of Jupiter. Saturn overthrew his father to become king of the gods, but was then overthrown himself by his son Jupiter.

How much would you weigh on Saturn? Because Saturn is bigger than the Earth, you would weigh more on Saturn than you do here. If you weigh 70 (32 kg) pounds on Earth, you would weigh 74.5 pounds (34 kg) on Saturn. Probably not as much as you thought, right? Keep reading to find out why.

The PlanetIn many ways, Saturn is similar to Jupiter, but it is much smaller. It is the second largest planet in

our Solar System and it is a gas giant like Jupiter. Under the clouds of methane, hydrogen and helium, the sky gradually turns into liquid until it becomes a giant ocean of liquid chemicals.

Saturn is the least dense planet in our Solar System. It is made up of mostly hydrogen and helium, which are the two lightest elements in the universe and thus make Saturn the lightest planet that we know of. This is why you wouldn't weigh as much on Saturn as you think you would because of its size. And because Saturn is so light, it does not have as much gravity. Interestingly, it is believed Saturn would actually be able to float in water because the hydrogen and helium that make up the planet are so lightweight.

Because Saturn is such a lightweight planet and it spins so fast, Saturn is not perfectly round like most of the other planets. Like Jupiter, Saturn is wider in the middle and more narrow near its top and bottom.

The RingsSaturn is most well-known for its rings. However, it is not the only planet with rings. Jupiter, Uranus and Neptune also have rings. Saturn is a favorite object for many observers. Its beautiful rings are 169,800 miles wide (approx 273,266 km). But the rings are amazingly thin. If you turned the rings on their side, they would be able to fit between the goal posts on a football field. The rings are split into categories, Ring A, Ring B, Ring C, Ring D, Ring E, Ring F and Ring G, totaling 7 in all. The rings are not solid but rather are made up of particles of ice, dust and rocks. The rings are held in place around Saturn by the moons that also orbit this large planet. The gravity of these moons also cause the gaps that are seen in between the rings.

Moons: Saturn has 53 official moons and 9 provisional (unofficial) moons. The most well-known of Saturn's moons is probably Titan. It is the second largest moon in the Solar System next to Jupiter's Ganymede. Titan is larger than the planet Mercury. Some of the other moons are Atlas, Calypso, Dione, Enceladus, Hyperion, Iapetus, Janus, Mimas, Phoebe, and Tethys.

Uranus means: In astronomy mythology, Uranus was the lord of the skies and husband of Earth. He was also the king of the gods until he was overthrown by his son Saturn.

How much would you weigh on Uranus? It would take you many years to fly a rocket to Uranus. When you arrived you would weigh less because Uranus' gravity is not as strong as the Earth's. If you weigh 70 pounds (32 kg) on Earth, you would weigh 62 pounds (28 kg) on Uranus.

The PlanetLike Jupiter and Saturn, Uranus is a gas giant. But Uranus is a little different. Unlike all the other planets and most of the moons in our Solar System, Uranus spins on its side. It is believed that long ago a very large object smashed into this planet. The crash was so powerful that it completely changed the direction of Uranus' planetary rotation. However, a more recent theory is

that the extreme tilt of Uranus' axis may have been caused by a large moon that was slowly pulled away from the planet by another large planet long ago when our Solar System was still new. It is thought that the gravitational pull of this moon moving away from Uranus may have caused it to tilt on its side.

Like Saturn, the thick atmosphere of Uranus is made up of methane, hydrogen and helium. But Uranus is an extremely cold planet. It has been called the "ice giant." It is believed that Uranus is made up of rock and ice and has a large rocky core. Because of the tremendous planetary pressure of Uranus, there could possibly be trillions of large diamonds in or on the surface of this planet.

Scientists also believe that on the surface of Uranus there may be a huge ocean. And, interestingly, it is thought that the temperature of this ocean may be extremely hot, maybe even as hot as 5000 degrees Fahrenheit (2760 Celsius).

Uranus is almost identical to the planet Neptune.

RingsUranus also has rings, though they don't stretch out as far as the rings of Saturn. The rings of Uranus are made up of black dust particles and large rocks.

Moons: Uranus has 27 moons. Five of these moons are large and the rest are smaller. The largest moon is Titania, followed by Oberon, Umbriel, Ariel and Miranda. Some of the smaller moons are named: Belinda, Bianca, Caliban, Cordelia, Cressida, Desdemona, Juliet, Ophelia, Portia, Puck, and Rosalind.

Neptune means: At first, Neptune was only the god of water, but later on this was extended to include the sea when he became associated with the Greek god Poseidon.

How much would you weigh on Neptune? If you weigh 70 pounds (32 kg) on the Earth, you would weigh 78.5 pounds (36 kg) on Neptune.

The PlanetFor many, centuries people did not know that this planet even existed. It was discovered by Johann Galle and Heinrich D'Arrest in 1846.

Neptune is the smallest of the four gas giants in our Solar System. Much like Saturn and Uranus, Neptune's atmosphere contains hydrogen, helium and methane.

Not much was known about Neptune until it was visited by the spacecraft Voyager 2 on August 25, 1989. Voyager 2 took many pictures of the planet, and much of what we know today about Neptune came from this single visit. These pictures show a brilliant blue planet with a few thin white clouds laced around its surface.

In Neptune's atmosphere, there is a large white cloud that moves around rather quickly. The "scooting" of this cloud around the atmosphere has led it to be named "Scooter."

When Voyager 2 visited Neptune, its pictures showed a giant storm much like the storm on Jupiter. This storm is called the "Great Dark Spot" because it appears as a dark oval shape on the surface of the planet. We do not know how long this storm has been active or if it is still present. More recently, the Hubble Space Telescope sent pictures back to Earth and there was no sign of the Great Dark Spot. These pictures did show two other dark spots that eventually faded away.

Neptune is a very windy place. No other planet in the Solar System has winds that are as strong as Neptune's. The winds near the Great Dark Spot were believed to have reached nearly 1,200 miles per hour (approx 1931 km per hour). Perhaps this extremely windy atmosphere contributes to the appearance and disappearance of the great dark spots.

RingsNeptune has six rings which circle the planet. These rings are believed to be fairly new. The rings are more irregular than the rings of other planets. There are areas of varying thickness throughout the rings.

Moons: Neptune has 13 moons that we know of. Because Neptune is so far away, it is difficult to see any of these worlds. There are probably many more moons orbiting this blue planet which we have not yet discovered. Perhaps you will be the astronomer who discovers some of these worlds. The first moon to be discovered was Triton. Triton was discovered by an amateur astronomer in England named William Lassell only 17 days after Neptune was discovered in 1846. The names of the other moons are: Despina, Galatea, Halimede, Laomedeia, Larissa, Naiad, Nereid, Neso, Proteus, Psamathe, Sao, and Thalassa.

Pluto means: Pluto was thought to be the god to whom all men must eventually go. Romans believed him to be the god of the underworld. In Greek mythology, he is known as Hades.

How much would you weigh on Pluto? Because Pluto is so small you would be very light if you visited. If you weigh 70 pounds (32 kg) on Earth, you would only weigh 4 pounds (2.5 kg) on Pluto.

The Dwarf PlanetPluto was the only planet to be named by a kid. After the planet was discovered in 1930, an 11-year-old girl who lived in Oxford, England, by the name of Venetia Burney, suggested that this new planet needed to be named after the Roman god of the underworld. Venetia's grandfather sent this suggestion to the Lowell Observatory and the name was accepted.

Pluto is smaller than 7 of the moons in the Solar System. It is about two-thirds smaller than Earth's moon. Because it is so small, many scientists don't consider it a planet at all. In 1999, a group of scientists attempted to re-classify Pluto as a comet. On August 24, 2006, Pluto's status was officially changed from planet to dwarf planet. For decades, children have been taught in

school that there are nine planets in our Solar System. However, with this change, there are now only eight planets. Also because of this change, there is a new category of small planets known as plutoids.

The only spacecraft to get somewhat close to Pluto was the Hubble Space Telescope. Hubble was able to take pictures of Pluto and its moons for scientists to study. Little is known about Pluto and its moons because it is so far away.

Moons: Pluto has 3 moons. The largest is named Charon. Charon is only slightly smaller than its parent Pluto. For this reason, Pluto and Charon are often called a double system. The Earth and its moon, Luna, are sometimes considered double planets. Pluto's two other moons are called Hydra and Nix.