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Activities at the Understand Level

Learners explain, summarize, discuss, give examples, review, compare, paraphrase, predict, outline, infer, and make sense out of information

–Space Exploration Activities

People have always studied what they could see in the sky.  Ancient people studied the Earth, the Moon, the stars.  They formed their own ideas about what they could see with their own eyes.  They used this information to think about the changing of the seasons which helped them to know such things as when to plant crops and when to harvest. In the 1600s, early astronomers were able to develop simple telescopes which lead to the discovery of new information about the solar system.  Today, astronomers use computers, telescopes, and a variety of spacecraft to study outer space.

Stanford Solar Center
Who was the first person to use a telescope to look at the Sun, the Moon, and the planets?
A space probe called Clementine orbited the moon in 1994 and took more than 3 million pictures.  Explain how these pictures have benefited scientists who study the moon.  What are some of the things they have learned from these pictures?
Hubble Space Telescope NASA
Describe the Hubble Space Telescope.  What does it do?  What are some things that the Hubble Space Telescope has discovered?  How does the Hubble Telescope get repaired?
Mission to Mars
Astronomers love to study Mars, and there have been many successful as well as many unsuccessful attempts to land scientific vehicles on the famous red planet.  Choose one of the missions, describe the type of vehicle that was sent to study Mars, and describe the goal of the mission and what astronomers hoped to learn.
Hubble Space Telescope
What are some of the benefits of the Hubble Space Telescope?
Chronology of Space Exploration
Browse through the different explorations of parts of our solar system.  Choose one of the explorations and write a brief summary of where it went, what it studied, and its significant findings.
Mauna Kea
The dormant volcano, Mauna Kea, in Hawaii has 13 telescopes on top of it, and they are from 11 different countries.  Astronomers love Mauna Kea!  Why is the top of this volcano so good for viewing the solar system?
What astronomer was among the first people to believe that the Sun was the center of the solar system and that the planets orbited around the Sun? 
What was the first space satellite to orbit the earth?  When was it launched?  How big was it? 
NASA Space Exploration
Who was the first person to orbit the Earth?  How long did he spend in space? What year did he orbit the Earth?  What country was he from?
NASA Space Exploration
Who was the first American astronaut in space?  How long was his flight?  When did he go into space?
Describe Ham the Chimp’s 1961 contributions to space exploration.
Describe Laika’s contribution to space travel.  What happened to Laika?
NASA Apollo 11
The Apollo 11 space mission landed the first people on the Moon.  Who were those people? Who took the actual first steps on the Moon? 
Americans and the Moon
Twelve American astronauts have landed on the Moon.  Who were they? They took photographs, collected rock and soil samples, and explored the Moon in a lunar rover. List some of their other activities.
NASA Space Shuttle
Explain why the space shuttle was called a “reusable space vehicle”.
Space Shuttle Program
What were some of the things that the space shuttle did?
Kids Cosmos Mars Rovers
Describe some of the scientific activities that the rovers that have landed on Mars have been able to do.
International Space Station
What is the International Space Station?  Describe what it is like inside the station.  What are some of the other spacecrafts that have interacted with the International Space Station?
NASA International Space Station
This NASA website has updates for the very most current information about what is happening aboard the International Space Station.  What is the latest news?
National Archives Space Exploration
Outline a timeline of space exploration.
The Near Earth Asteroid Rendezvous (NEAR) mission had the goal to study asteroids.  It sent a spacecraft directly to an asteroid named Eros which is the 2nd largest asteroid close to Earth.  Why are asteroids of such interest to scientists?  Click on Results---what are some of the findings of the NEAR mission?
Deep Impact
The Deep Impact mission in 2005 studied comets.  A special spacecraft was launched that had a smaller spacecraft attached to it.  Once the main spacecraft was close to a comet called Tempel 1, it sent the smaller spacecraft to crash into Tempel 1.  Scientists called the smaller crashed spacecraft the impactor.  The impactor was able to gather dust and debris and bits of the comet for astronomers to study.  What were some things that the scientists learned about comets?
Planets Activities

Planets!  We used to have nine, and now we have eight!  Astronomers consider a planet to be an object that orbits a star and is big enough to have enough gravity to give it a round or spherical shape.  Planets are spheres because gravity pulls their mass toward their centers which creates the round shape.  In order for a space object to be a planet, it also must have its own orbit and not cross the orbit of any other planet or large body (like an asteroid).

The 1st planet from the Sun
  1. Mercury is named after a Roman god. What was he the god of? Who is his Greek counterpart?
  2. According to this site, approximately how long ago did people start watching Mercury?
  3. What two spacecrafts have visited Mercury?  ("Visited" implies that spacecraft with imaging satellites fly near the planet and transmit back photographs of the planet. They do not actually land on the planet--except for Mars). What was the spacecrafts that visited Mercury?
  4. Why hasn't the Hubble Space Telescope (HST) been able to safely map Mercury?
  5. What is the temperature range on Mercury?
  6. What is the densest body in our solar system?
  7. How many moons does Mercury have?
  8. If you're star/planet-gazing in your backyard on a dark and clear night, can you see Mercury with the naked eye?
The 2nd planet from the Sun
  1. This planet is named after the Roman goddess Venus. What is she the goddess of?
  2. Venus is the brightest object in the sky except for the Sun and moon. Historically, what two other names was Venus sometimes known as?
  3. What was the first spacecraft to visit Venus in 1962?
  4. Venus rotates very slowly. How many earth days does it take to make up one Venus day?
  5. In its size and surface, Venus is most similar to what other planet?
  6. Venus is farther from the Sun than Mercury, but its surface is much hotter than that of Mercury. Explain why.
  7. What do Venus and Hawaii have in common?
  8. The moon is full of craters. Mars has craters. Even the earth has a few craters. Why doesn't Venus have any craters?
The 4th planet from the Sun
  1. After the earth, Mars is the most studied of the 9 planets. List the spacecraft that have visited Mars and when they visited.
  2. In Fahrenheit, what is the average temperature on Mars? What is the range of temperatures on Mars?
  3. Explain why Mars has about the same amount of land surface area as earth even though Mars is much smaller.
  4. Mars has the highest mountain in the entire solar system. What is it and how tall is it? By comparison, this is almost 3 times taller than Mt. Everest on Earth!
  5. Hellas Planitia is one of the biggest craters on Mars. It was caused by the impact of a meteor. How wide and deep is it? By comparison, this is almost 6 times wider than the largest impact crater on Earth.
  6. What gases in what percentages make up Mars's atmosphere?
  7. What are the ice caps on both poles of Mars made of?
  8. What was concluded about the evidence of life on Mars from the data gathered from the Viking exploration?
  9. Can you see Mars at night without a telescope?
The 5th planet from the Sun
  1. Jupiter is huge! How big is it compared to all the other planets?
  2. Jupiter is the 4th brightest object in the night sky. What are the 1st, 2nd, and 3rd brightest objects?
  3. Who first discovered Jupiter's 4 large moons? In what year did this person discover them?
  4. What spacecraft first visited Jupiter?
  5. What kind of surface does Jupiter have?
  6. What two main gasses make up Jupiter and in what percentages are they found?
  7. What is the core of Jupiter probably made up of?
  8. Jupiter is famous for having something that scientists call the GRS. What do those initials stand for? How big is the GRS in comparison to the earth?
  9. Jupiter actually has rings like Saturn! What are they made of?
  10. In July 1994, what collided with Jupiter?
  11. Jupiter has many moons? What are the names of the 4 largest moons?
The 6th planet from the Sun
  1. In Roman mythology, what is Saturn the god of?
  2. Who was the 1st person to observe Saturn with a telescope?
  3. Saturn is one of the gas planets. What are the percentages of the gases of which it is composed?
  4. How many of Saturn's rings can be seen from earth? The Voyager satellite sent back pictures of additional rings.
  5. What are the rings of Saturn composed of?
  6. If you are standing outside on a dark and starry night, can you see Saturn without a telescope?
  7. When you are looking at objects in the night sky, how can you tell the difference between a star and a planet?
  8. Saturn has a lot of satellites (moons).  How many?  (It’s possible that Saturn has additional moons that have not yet been discovered).
The 7th planet from the Sun
  1. Who discovered Uranus? When was it discovered? It had been seen previously, but what did early observers think it was?
  2. What names did this planet have before it was officially named "Uranus"?
  3. Uranus has only been visited by one spacecraft. Which one?
  4. What is Uranus primarily composed of?
  5. What is the atmosphere of Uranus composed of?
  6. Why is Uranus blue?
  7. Uranus has quite a few moons!  Unlike the names of other planets and moons that come from mythology, where do the names of the Uranus's moons come from?
The 8th planet from the Sun. It's kind of like a huge, round popsicle.
  1. This planet was named after the Roman god, Neptune. What was he the god of?
  2. Which spacecraft has visited Neptune?
  3. Why is Neptune blue?
  4. What was Neptune's most prominent feature called? Scientists weren't even exactly sure what it really was. What happened to it?
  5. Did you know that Neptune has rings just like Saturn? Observations from the earth have never shown them clearly, but when Voyager 2 passed that way, the rings were clearly visible. The rings even have names! What are some of the names? Do they sound like names from mythology?
  6. If you're star/planet-gazing in your backyard on a dark and clear night, can you see Neptune with the naked eye?
Cool Cosmos - Venus
What is the atmosphere of Venus mostly composed of?
Universe Today
Why is it so difficult for astronomers to study the surface of Venus?
Planet Mercury
The surface of Mercury is very wrinkled with many folds and ridges.  What do scientists think caused this smallest planet to be so wrinkled?
Universe Today - Mars
What gives Mars its red color?
Callisto - Jupiter
Callisto is one of the moons of Jupiter.  It has more craters than almost any other body in our solar system.  Some of the craters are enormous!  What is the name of the largest impact crater on Callisto and how wide is it? 
Universe Today - Uranus
Uranus has a very unusual rotation.  All planets have an imaginary line called an axis that runs between its north and south poles.  The tilt of the Earth on its axis is 23.5°.  What is the tilt of Uranus?  What does this mean in terms of its rotation?
Cool Cosmos - Venus
A day on a planet is the amount of time that it takes the planet to spin once on its imaginary axis.  It takes the Earth close to 24 hours to spin once around, and so a day on the Earth is 24 hours long.  Venus spins very slowly!  How many hours long is a day on Venus?  A day on Venus is like how many Earth days?  Interesting fact: Venus’s year (the amount of time it takes to orbit the Sun) is like 224 Earth days which means that Venus’s day is longer than its year!

Name that Planet
With a classmate, do research to determine which planet the interesting information refers to.

Awesome Planet Information Which Planet?

This planet is the farthest planet from the Sun.


This planet is the closest planet to the Sun.


This planet is very stormy.  It has one particular storm that is so big that it has its own name : the Great Red Spot!  The Great Red Spot has been storming around the planet for at least 100 years!


This planet has the biggest temperature range of any planets.  Because it has no atmosphere, the temperature can range from 800°F to -300°F.


The atmosphere of this planet is made up mostly of carbon dioxide.


This planet is a gas giant.  (There are 4 correct answers for this).


This is the 2nd largest planet.


This planet looks like it is blue---even though it has no water on it.


All planets have an oval-shaped or elliptical orbit around the Sun.  This planet’s orbit is the most nearly circular of all the planets.


This planet has many moons.  Some of the moons are Oberon, Titania, Miranda, Ariel, and Umbriel.


This planet has a very large moon named Titan.


In 1938, a radio broadcast called War of the World was listened to by thousands of people in the U.S.  Many of those people mistakenly thought that the broadcast was really a news report, and they thought that the events in the story were true.  Many Americans mistakenly thought that the Earth was being invaded by creatures from this planet.


This planet rotates so fast that its days are only 10 Earth hours long.


This planet has no atmosphere.  So if you were to stand on this planet, the sky would always be black, and you could see stars during the day as well as during the night.


This planet has the tallest volcano in the solar system, and it is called Olympus Mons.  Olympus Mons is three times higher than Mount Everest on Earth.


This planet is named after the main Roman god.


This planet has a very high mountain called Maat Mons.


These 4 planets all have rings.  Of course, we think about Saturn when we think about ringed planets because its rings are the most visible.  But there are really 4 planets (including Saturn) in our solar system that have rings!


This planet is not very dense.  It is so light that it could actually float on water if there was an ocean big enough to hold it.


This is the smallest planet in our solar system.


This planet often has very large dust storms that can last for months and cover the entire planet.


This is the only planet in the solar system that is not named after a Greek or Roman god or goddess.


This is the hottest planet in our solar system.


This planet has the biggest moon in the solar system. The moon is called Ganymede. Ganymede is even bigger than Mercury.


This planet is named after the Roman god of agriculture.


These 2 planets have no moon.


This planet is the brightest planet that can be viewed from Earth.


This planet has the largest volcano in our solar system.


This planet has the longest year (as calculated in earth years).


It takes the Earth 365 days to orbit the Sun.  It takes this planet 88 days to orbit the Sun.


This is the largest planet in our solar system.


Water covers 2/3 of this planet.


Scientists landed an unmanned vehicle called a rover on this planet in order to explore its surface.


This is sometimes called the red planet.


The Sun’s rays are 7 times stronger on this planet than they are on Earth.


This planet has more probes sent to it than any other planet.


This planet’s atmosphere is made up almost entirely of carbon dioxide.


Earth Activities

Our planet Earth is an amazing planet because it has all the right conditions to support plant and animal life.  It has water, an appropriate temperature, and an atmosphere with elements in proportions that foster life.

The 3rd planet from the Sun

  1. How is earth's name different than the other planets? If the naming of earth had followed the pattern for the other planets, what might earth's name have been?
  2. In what century did we finally figure out that the earth is actually just a planet? In what century did we finally have maps of our entire planet? What aided in the mapping of earth?
  3. List the layers of the earth.
  4. Compare the thickness of the earth's crust under the continents to the crust under the oceans.
  5. Which layers of the earth are solid and which are semi-fluid?
  6. Most of the mass of the earth is in what layer? In which layer is most of the rest of the mass?
  7. What element makes up the composition of most of the core of the earth?
  8. Describe plate tectonics. How many major plates are there? About how many small plates are there? What phenomenon is common at the boundaries of plates?
  9. What percentage of the earth's surface is covered with water? In our solar system, where else does water exist in liquid form? What role does the heat capacity of the oceans play in our climate? What other process is liquid water responsible for on earth that is unique in the solar system?
  10. What is the atmosphere of the earth made up of?
  11. What causes the aurora borealis?
  12. What are the Van Allen radiation belts? What produces them?


Where does the Earth rank in planet size among all 8 planets? In what century was it finally understood that the Earth was another planet and not the center of the solar system?
Planets for Kids
How long does it take the Earth to orbit the Sun?  Explain how Leap Year occurs.  How far is the Earth from the Sun?
NASA Solar System Exploration
How long does it take the Earth to rotate one time?  What is one way that the Earth is different from all the other planets in the solar system?
NASA Planets
How did the Earth get its name?
Earth Statistics
The Earth does not orbit the Sun in a totally upright position. The Earth tilts. The tilt of the Earth is responsible for the seasons that we experience on the Earth. What is the angle in degrees of the tilt of the Earth's axis?
Earth's Atmosphere
What is the percentage of each of the gases that make up the Earth's atmosphere?  How does the atmosphere protect the Earth?  How does the atmosphere benefit the Earth?
Science for Kids
When you are standing on Earth and looking up into the sky, where does outer space start?
ESA Kids
What does it mean that Earth is considered to be in “the Goldilocks zone” in our solar system?
Moon Activities

Of the eight planets in our solar system, all but two (Mercury and Venus) have at least one natural satellite or moon that orbits around it. The Earth, of course, has one moon.  It’s the only moon in the solar system that man has walked on.  It is also the moon that astronomers have studied the most. 

Universe Today
The Moon does not give off its own light.  So why does it glow in the Earth’s night sky?
National Geographic Today
How do scientists think that the Earth’s moon may have formed?
Moon Project
Why does the Moon have more craters than the earth?
NASA for Kids
What keep the Earth’s Moon from flying off into space?  How does the Moon stay in orbit around the Earth?
Windows to the Universe
How long does it take for the Moon to orbit the Earth? 
Earth’s Moon
What is the so-called Man in the Moon?
What is the relationships between the Moon and the Earth’s ocean tides?
Why does the Moon still have the footprints and tire tracks that were made on its surface from the first Moon landing in 1969?
Phases of the Moon Activities

The Moon, of course, has no light of its own. It shines because it reflects light from the Sun. As the Moon orbits the Earth, we see different portions of it lit up, and the Moon appears to change shape. These changing shapes are called the phases of the Moon. These phases take place over just the half of the Moon that faces the Earth. (Remember, we only ever really see the side of the Moon that faces the earth, and we never see the far side or dark side of the Moon.) So over the course of a month which is 29.5 days, the Moon changes from new (which means you can't see it at all) to 1st quarter (which means you see half of the part of the Moon that faces us) to full (which means you see all of that half that faces us) to last quarter (which means you see the other half of the part that faces us) and then back to new again. Get it? So in other words, when the Moon is new, it means that the Sun is shining on the dark side that we never see. When the Moon is full, the Sun is shining fully on the side that we always see. When the Moon is at 1st quarter, the Sun is shining on only half of the part of the Moon we can see.

Phases of the Moon
A new moon is the phase where the side of the Moon facing the Earth is not lit at all by the Sun.  A full moon is the phase where the side of the Moon facing the Earth is entirely lit by the Sun.  What are the other phases of the Moon?
WikiHow Moon
What do the terms wax and wane mean in terms of the Moon?
Ask the Space Scientist – Astonomer’s Cafe
What is a blue moon?  Look at the chart in the middle of the page.  When was the last blue moon?  When is the next blue moon?  On what date will there be a blue moon in the year 2045?
Earth and Moon Viewer
Scroll down about one-fourth of the way on the page to "Viewing the Moon." Click on the choice to view the moon from the Earth. From the image that you see (which is a current satellite image), what phase does the Moon appear to be in? From the chart, you can see the phase of the Moon as a percentage with 100% being a full moon and 0% being a new moon. When is the next new moon? When was the last full moon?
The Hitchhiker's Guide To the Moon
This site shows today's date and the phase of the Moon. What is it? It will be expressed something like "A 19 day old waning moon" which means that it is 19 days from the last full moon and getting smaller. (The complete cycle is 29.5 days). Have you figured out yet if it is a crescent or gibbous? The site Moon Phases also displays graphical representations of the phases of the Moon for today's date or any date you select.
Sun Activities

The Sun is at the center of our solar system. It is a gigantic ball of extremely hot gases that is the source of all life on our Earth. The eight planets and their moons as well as asteroids, meteoroids, comets, and everything else in the solar system orbit around the Sun.  Our Sun is so big in comparison to planets that it contains 99% of the total mass of our solar system. The Sun is a star that has been burning for billions of years and will burn for billions of years into the future.

Science Kids Space Facts
What are the 2 main gasses that make up the Sun?  What are their percentages?
ESA Kids
What would the Earth be like without the Sun?
Cool Cosmos
What is the force that keeps the planets, asteroids, and every other object in our solar system orbiting the Sun? 
Galileo Project
What are sunspots? 
Solar Viewing
Why should we never stare at the Sun?  What are some safe ways to view the Sun?
The Sun has storms or solar activity where it releases huge bursts of energy.  Describe our Sun’s solar cycle.
Northern Lights
What causes aurora borealis or northern/southern lights?  How are auroras related to the Sun?
Sun Today
SOHO, Solar and Heliosperic Observatory, is a space probe that carries many different kinds of instruments to study the Sun and send information back to the Earth.  What are some parts of the Sun the SOHO will study?
How the Sun Works
What is the part of the Sun that we can actually see from Earth called?
Cool Cosmos
How far away is the Sun from the Earth? 
Ask an Astronomer
How long does it take for light from the Sun to reach the Earth?  Light from the next closest star to the Earth takes four years to reach us!
ESA Kids
What kind of damage can ultraviolet light from the Sun do to humans?
Star Activities

Stars are objects in galaxies that are composed of hot gasses.  Even though stars may look very similar when we are gazing into the night sky, there are actually many different kinds of stars that are different sizes, colors, and temperatures.   Most of the stars in our sky are actually bigger than our own Sun, but they look so small because they are very far away.

Cool Cosmos
What is a star?
Star Birth
Explain the process of how a star is made.
Star Death
Do stars last forever?  What eventually happens to them?  Explain the process of their demise.
Stars and Galaxies
What are the characteristics of the different kinds of stars: red stars, blue-white stars, yellow stars? What kind of star is the Earth’s Sun?
Stars and Galaxies
Explain what a supernova is.
Universe Today
Explain why stars appear to twinkle and planets usually appear not to twinkle.
Astronomy for Kids
There are many different kinds of stars.  What are some of the types of stars in the universe?  What is the nearest star to the Earth (other than the Sun)?
When we make a wish on a falling star or shooting star, what are we really wishing on?
Constellation Activities

Since ancient times, people have studied the night sky and looked at the stars and have given names to the groups of stars.  Groups of stars were often named after animals or after characters in ancient mythologies.  These groups of stars that have been given imaginary stories are called constellations.

Cool Cosmos
What is a constellation?
Great Bear and Little Bear
The Ursa Major and Ursa Minor constellations have an interesting background tale.  Summarize the story of how they got their names.
Earth Sky
How can you find true north by looking at the star called Polaris which is part of the constellation called Ursa Minor?
Astonomy for Kids - Orion
What are some of the creative shapes and patterns that people have imagined for constellations? How many constellations are there?  What is the constellation Orion named for?  What are the two brightest stars in Orion?  What is the constellation Draco shaped like?  How can constellations be used for navigation?
Big and Little Dipper
The Big and Little Dipper constellations (part of Ursa Major and Ursa Minor) are two of the most recognizable constellations in the northern hemisphere.  When you are in your yard at night, which direction (besides up) should you look to see the Big Dipper and Little Dipper?  The Big Dipper is a little easier to find in the night sky than the Little Dipper.  How can you use the Big Dipper to find the Little Dipper?
NASA Drinking Gourd
How was the North Star beneficial to slaves in America?  What was their other name for the Big Dipper?
Windows to the Universe
What did ancient peoples think that the constellation Leo looked like?
Canis Major and Canis Minor
Just like there are Ursa Major (Big Bear) and Ursa Minor (Small Bear) constellations, there are also Big and Small Dog constellations.  What famous constellation are Canis Major and Canis Minor close to?  What is the name of the brightest star in Canis Major?
Northern Hemisphere Constellations
Choose one of the constellations that are viewable in the Northern Hemisphere and describe what it looks like and summarize the story behind its name.
Northern Hemisphere Constellations
Southern Hemisphere Constellations
We see different stars and constellations in the sky depending on our location.  Star gazers in North Dakota have a different view of the stars than star gazers in Rio de Janeiro.  Because of the tilt of the Earth, we can even see different stars and constellations depending on the season of the year.  Circumpolar constellations do not rise or set which means that they can be seen all year long, and their viewing availability does not change with the seasons.  Find a constellation in the Northern Hemisphere or Southern Hemisphere and describe its appearance and its story.
Asteroids Activities

Asteroids are simply chunks of rock and metal that orbit the Sun in the same way that planets orbit. They come in all sizes and shapes. Some are as big as boulders, some are as big as mountains, and some are as big as the moons that orbit many of the planets. They can be globe-shaped or pear-shaped or have strange irregular shapes like any other big rock. Their shapes often change as they smash into each other as they orbit. The smaller bits and pieces that break off asteroids are called meteoroids.

Astronomers used to think that asteroids came from a planet that may have existed between Mars and Jupiter. They thought that perhaps this planet had exploded. This would explain why some asteroids are composed of all rock, some are all metal, and some are rock and metal mixed--the same compositions that would have made up the mantle, core, and crust of the exploded planet. Most astronomers today, however, think that asteroids are leftover material from when the solar system was formed.

StarChild : The Asteroid Belt
How do scientists think that Mars acquired two of its satellites or moons? According to this site, how does Jupiter's large size and strong gravitational pull benefit other planets? 
Astronomy for Kids : Asteroids
Between which 2 planets do many asteroids orbit? Some asteroids are very large! Surprisingly, what do some asteroids have orbiting around them? 
Name the largest known asteroid. Is there an asteroid that can be seen without a telescope? If so, which one?
Asteroids can be categorized in two different ways.  One of the classifications involves their position in the solar system.  What are the 3 categories for this classification system and where are the asteroids located?
Views of the Solar System: Asteroids
What are asteroids that are on a collision course for earth called? Beginning in 1991 and 1993, how did astronomers gain new knowledge about asteroids? 
Asteroid Belt
What is the asteroid belt?  How many asteroids do scientists estimate are in the asteroid belt?  Are the asteroids close together?  What is the biggest asteroid in the belt?
Ida and Dactyl
Some asteroids are so large or have been studied enough that they have been given names. Information about the asteroid, Ida, was gathered by the spacecraft Galileo in 1993 when it was on its way to gather information about Jupiter. If you look at the pictures of Ida on this website, it kind of looks like a great big potato.

When the images taken by the Galileo spacecraft were transmitted to earth, astronomers discovered Dactyl. What is Dactyl? How do scientists think that Dactyl was formed?

Scroll down the page to the image called "Ida and Dactyl in Color” to see the size and distance relationship between these two asteroids.

Near Earth Object Program
The danger from the Earth being hit by a large asteroid is not just from the impact alone but also from the amount of dust that would be thrown into the Earth's stratosphere. What effect would all this dust have on the Earth? 
This is a list of the top PHAs. What does PHA stand for? 
NASA Space Calendar
Find the current month. Scroll down through the astronomical events for this month. Is there an asteroid that is having its closest approach to earth?   If so, what is the name of the asteroid?
–Meteor Activities

A meteor is simply a piece of space rock zooming through Earth’s atmosphere.  Most of these pieces of space rock burn up in the atmosphere and never reach the Earth.  The pieces of space rock that make it through Earth’s atmosphere and hit the ground or the ocean are called meteorites. 

When a piece of space rock is orbiting the Sun, it is called a meteoroid.  If a meteoroid enters the Earth’s atmosphere (where it usually burns up), it is called a meteor.  If a meteor hits the Earth’s surface it is called a meteorite.

What is a falling star or a shooting star?
Meteor Facts
About how many meteors enter the Earth’s atmosphere every day?  What is a meteor shower?
Kids Astronomy
What are the 3 main types of meteorites?
In general, where do most meteorites land on the Earth?
Meteor Crater
Describe Meteor Crater in Arizona.  This crater is also called Barringer Crater.
Gosses Bluff
Where is Gosses Bluff Crater?  How was it formed?
ESA Kids
What are meteoroids? What are meteors?  What are meteorites?
ESA Kids
What are the Leonid showers that take place every year?
–Comets Activities

Comets have been called big, dirty snowballs because they are composed of rock dust wrapped around a big ball of ice. The rock dust and ice may be matter left over from the time the solar system was formed.

As a comet gets closer to the Sun, the heat of the Sun starts to melt the ice of the comet and turn it to gas. The gas and the dust are released and form a cloud that reflects sunlight (a comet has no light of its own), and the comet becomes visible. This cloud of dust surrounding the nucleus of the comet is called the coma. The nucleus and the coma together are called the head of the comet. The comet grows in size and brightness as more and more gas and dust are released from its coma. The solar winds cause the dust and gas to gather behind the comet, giving it a tail. In its long elliptical orbit, after the comet loops around the Sun, it begins its long journey back to the distant part of the solar system. It gradually appears smaller and dimmer, and it loses its tail as it cools down and freezes. Eventually, it disappears from view.

Most comets follow huge orbits in the solar system and may not return to our view in Earth's skies for thousands of years if ever. However, some comets appear at regular and more frequent intervals. They follow orbits that stay within or close to the orbits of the planets. These comets are called periodic or regular comets. The most famous one is Halley's Comet which appears every 75-76 years. It is named after the English astronomer Edmond Halley.

People have been aware of comets since ancient times. Some people believed that comets were made of poisonous gases and that if the earth passed through the tail of a comet, Earth's inhabitants would be killed. During Halley's Comet's 1910 visit, merchants even sold comet pills to protect people from the gasses.

Science for Kids
What is a comet?  What is a short term comet?  What is a long term comet?
Cool Cosmos
What are the parts of a comet?
Comets are invisible except when they are near what?
Describe the sizes of comets.
Science for Kids
What happens when a comets gets close to Earth?  What happens when comets get close to the Sun?  What happens after comets orbit the Sun hundreds of times?  What do scientists think that some asteroids are?
Kuiper Belt
What is the Kuiper Belt? (Kuiper is pronounced with a long i sound so that Kuiper rhymes with viper).
NASA Kuiper Belt                                        
Why do scientists think that the comets and frozen objects in the Kuiper Belt are important?
According to this site, about how many comets do scientists think orbit the Sun? About how long can the tails of comets get? (The figure is given in kilometers. Convert it to miles. A kilometer is .62 miles.)
How does the heat of the Sun enable us to sometimes see comets?
Comets – Oort Cloud
Some astronomers think that there may be a huge grouping of about a billion comets on the outskirts of our solar system. They call this the Oort Cloud.  Comets in the Oort Cloud are too far away for even astronomers to see. It is only when they travel toward the Sun in their orbit that they become visible. Why do comets sometimes leave the Oort Cloud?
Global Telescope Network
Comets orbit the Sun just like planets do.  There are short-period comets that take less than 200 years to complete one orbit around the Sun.  Where do astronomers think that most short-period comets come from?  There are also long-period comets which take 1,000 or more years to orbit the Sun.  Where do astronomers think that most long-period comets come from?
Halley's Comet
For how long have people on earth been observing Halley's Comet? On what famous medieval art piece does Halley's Comet appear?
Ask an Astronomer
When will Halley's comet next be visible from earth?
Shoemaker-Levy 9 
Shoemaker-Levy 9 was a famous comet that broke apart in space.  What happened to parts of the comet?  Watch a short video reenactment of the impact.
What were the objectives of the Stardust exploratory mission?  What did scientists find out from the results of the mission?
What are NEOs?   Click on Close Approaches from the menu at the top.  What’s the next close approach date?
–Eclipse Activities

Both the Moon and the Earth cast a shadow as the light of the Sun falls on them. A lunar eclipse occurs when the Moon passes into the Earth's shadow in space.

A solar eclipse happens when the Moon passes in front of the Sun during the day and blocks its light to the Earth. If the Moon only partly covers the Sun, it is a partial eclipse. In order to fully see a solar eclipse, you have to be in the right place at the right time. The part of the Earth where you can see the full solar eclipse is called the path of totality. The path of totality is usually only about 75-100 miles wide because the Moon is very small compared to the size of the Sun. Only people in the path of totality actually see the full eclipse; everyone else sees a partial eclipse. A total eclipse of the Sun is only visible from any given spot on Earth every 360 years.

From ancient times, eclipses have elicited feelings of fascination and fear from observers. Ancient peoples often thought that eclipses were signs from angry gods or warnings of impending doom. Eclipses ARE fascinating and often unforgettable. Today there are people who are ardent eclipse followers. They track current lunar and solar eclipses and travel to those places on the globe where the eclipses can best be observed.

Lunar and Solar Eclipses
Explain how a solar eclipse forms.  Explain how a lunar eclipse forms.
NOAA Eclipse Page
Which kind of eclipse—solar or lunar-- is more common?
Explain the difference between a total eclipse and a partial eclipse.
Total Solar Eclipse
About how long can a total eclipse of the Sun last?
Moon Eclipses
Lunar eclipses happen 2-3 times a year.  Explain why lunar eclipses take place.
Solar Eclipses
Check out the solar eclipse chart from NASA.  When is the next solar eclipse?  In what part of the world can it be viewed from?
How to View an Eclipse
What are some safe ways to view a solar eclipse?
–Solar System Activities

Our solar system is simply everything in outer space that orbits around our Sun.

Copernicus was a scientist who was born in Poland in the mid 1400s.  What were his contributions to the study of the solar system?
Kids Astonomy - Galileo
Galileo was an Italian scientist who was born in the city of Pisa in the mid 1500s.  What were some of his contributions to the study of the solar system?
Light Years
Lights travels at the speed of 186,282 miles per second.  The distance that light travels in one year  is called a light year.  Astronomers use lights years to measure distances in outer space.  Why do astronomers need to use light years?  How big is the Milky Way in light years?
What are the different parts of our solar system? What force keeps planets, asteroids, and comets all rotating around our Sun?
What designation did Pluto used to have?  What is its designation now? Pluto is located in a region of our solar system that is mostly known for containing millions of comets—what is the area where Pluto is located called?  How big is Pluto?
Kids Astronomy
How did Pluto get its name?
Science Kids Space Facts
What is a dwarf planet?  What are the dwarf planets that are currently recognized?
The asteroid, Ceres, has had its status changed from asteroid to dwarf planet.  Where is it located?
Dwarf Planets
Pluto, of course, is no longer considered to be a planet.  It has been classified as a dwarf planet.  There are currently 5 bodies with the designation of dwarf planet.  Besides Pluto, what are the other 4 dwarf planets?  Where are each of the dwarf planets located?
Windows to the Universe: Planets
What is the difference between a regular planet and a dwarf planet?
What is the name of the tallest mountains in the solar system?  What planet are they located on?  By comparison, Mt. Everest on the Earth is about 29,000 feet high.  The tallest mountain in the solar system is about 37,000 feet high.
Astronomy for Kids – Black Holes
How are black holes formed? Why can’t we see black holes?
NASA Black Holes
What is the force that keeps black holes together and pulls other objects toward them?
––Galaxy Activities

Our Milky Way galaxy is not the only galaxy in the universe.  But it is the most interesting, because WE live in it! 

Astronomy for Kids - Galaxies
What is a galaxy?  What is the closest galaxy to our galaxy, the Milky Way?
NASA Solar System
Where is our solar system located within the Milky Way?
Kids Astronomy
There are billions of galaxies in the universe.  Astronomers call the galaxies that are close to the Milky Way the Local Group.  What are the 3 largest galaxies in the Local Group?
About how many stars are in our galaxy, the Milky Way? About how many galaxies are in the universe?  What do most galaxies have in the center of them?
Many astronomers think that there are 4 basic galaxy shapes.  What are they?  Which kind of galaxy is our galaxy, the Milky Way?

–Seasons Activities

On the Earth, we get warmth and light from the Sun. The tilt of the Earth as it rotates around the Sun causes us to have differing amounts of warmth from the Sun and is why we have different seasons.

The Earth does not rotate on it axis in a strait vertical manner.  The Earth is tilted on its axis at an angle of about 23.5°.  It is this tilt of the Earth on its axis as it orbits around the Sun that causes the Earth’s seasons.  When the tilt of the Earth in the Northern Hemisphere is pointing toward the Sun, it is summer.  When the tilt of the earth in the Northern Hemisphere is pointing away from the Sun, it is winter.

When the North Pole is tipped toward the Sun and the South Pole is tipped away from the Sun, it is summer in the northern hemisphere and winter in the southern hemisphere.

We live in the northern hemisphere. When the northern hemisphere of the Earth is tilted toward the Sun, Earth receives the most direct and intense solar energy. It also has more hours of daylight. This is when the northern hemisphere has its warmest season, summer

The Science of the Seasons
Why does the tilt of the Earth matter as to seasons of the Earth?  How does the angle of the Sun affect the seasons?
When does spring start in the northern hemisphere?  Describe the tilt of the earth during spring in the northern hemisphere.
When does summer start in the northern hemisphere?  Describe the tilt of the earth during summer in the northern hemisphere.
When does autumn start in the northern hemisphere?  Describe the tilt of the earth during autumn in the northern hemisphere.
When does winter start in the northern hemisphere?  Describe the tilt of the earth during winter in the northern hemisphere.
Study of the Earth
What are the season like in the temperate zones around the middle of the Earth?
Curiosity Corner
What would the Earth be like if the Earth did not tilt on its axis?
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