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Hi, I'm Melissa Joan Hart. You might know me as Sabrina the Teenage Witch.

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I just made up that stuff so Morgan would leave.

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Oh, I get it. No I don't.

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Sabrina, I'm no expert on magic, but it looks to me like you're under a spell.

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Spell?

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You're a witch, remember?

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Oh my gosh, you're right!

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Hey, I never have to go shopping again!

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Although I play a student with some extra special abilities, I'm here to tell you that in real life, there are no shortcuts to your education.

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I feel like a Porsche.

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I don't drive a stick.

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You do now!

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Learning math, science, and technology will help you work towards your dreams.

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In this episode of NASA Connect, you'll learn how awesome our sun really is.

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You'll observe NASA engineers and researchers using math, science, and technology to explore the sun-earth connection.

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In your classroom, you'll do a cool hands-on activity as you chart the sun's solar cycles.

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And using the instructional technology activity, you'll explore the web to discover even more about the sun-earth connections.

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So stay tuned as hosts Jennifer Pulley and Dan Giroux take you on another exciting episode of NASA Connect.

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Hi, welcome to NASA Connect, the show that connects you to math, science, technology, and NASA.

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I'm Dan Giroux.

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And I'm Jennifer Pulley.

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Welcome to the Maryland Science Center here in Baltimore, Maryland, home of the Hubble Space Telescope National Visitor Center.

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Today's show is about the sun.

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Did you know that it would take more than one million Earths to fill up the sun?

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And get this, more than 99% of all matter in our solar system is in the sun.

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It only takes about eight minutes for light from the sun to reach Earth.

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And as big as our sun is, it's only considered an average-sized star.

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Here's another interesting fact.

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In 1989, the sun actually knocked out power in Canada.

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You mean the sun stopped electricity on the Earth?

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That's right.

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We'll tell you later how it happened.

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In the next half hour, we hope to give you a better appreciation for how the sun works, how it affects us here on Earth.

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And how NASA researchers are studying the sun.

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Right, but before we continue, there are a few things you and your teacher need to know.

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First, teachers, make sure you have the lesson guide for today's program.

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It can be downloaded from our NASA Connect website.

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You'll find a great math-based hands-on activity and a description of our instructional technology components.

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Kids, you'll want to keep your eyes on Norbert, because every time he appears with questions, like this,

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have your cue cards from the lesson guide and your brain ready to answer the questions he gives you.

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Oh, and teachers, if you are watching a tape version of this program,

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every time you see Norbert with a remote, that's your cue to pause the videotape and discuss the cue card questions.

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And now, back to the sun.

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Stan, stand a little more to my right, please.

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Oh, sorry.

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Thank you.

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The sun is our nearest star. It provides us with warmth and light.

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We all know that the sun is important to life on Earth,

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but few of us have been given a good description of the sun and its composition.

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Our sun is an average star, similar to millions of others in the universe, but it's a big energy machine.

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If you could capture the energy the sun produces in one second,

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that would supply the United States with enough energy for the next 13 billion years.

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Where does the sun's power come from?

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Good question. The basic energy source for the sun comes from nuclear fusion,

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and this is when mass particles combine and tons of energy are released.

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The core, or innermost part of the sun, is made of hydrogen.

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The sun is so dense, and its size is so large,

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that light released from the core takes about 100,000 years to make its way to the surface.

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If the sun were to stop producing energy today,

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it would take 100,000 years for significant effects to be felt at the Earth.

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Scientists think there is enough hydrogen on the sun to continue producing energy for another 7 billion years.

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For many centuries, little was known about the sun.

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However, in the early 1600s, the Italian scientist Galileo used a telescope to take a closer look at the sun.

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He found dark spots that occasionally appeared and drifted across the sun.

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He also noticed that the dark spots on the sun's surface were constantly changing.

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These are called sunspots.

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What are sunspots?

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Let's find out. NASA Goddard's Dr. Eric Christian has some answers for us at the Naval Observatory.

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It's a blast!

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Thanks, Stan. The sun is a fascinating place and a brilliant object to observe.

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We observe the sun through telescopes like this one here at the Naval Observatory in Washington, D.C.

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But satellites help us, too.

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To get a better understanding of the sun, let's look at its different parts.

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The visible surface of the sun, now which we can actually see with the human eye, is called the photosphere.

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Temperatures here are around 6,000 degrees Celsius.

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The next two outer layers of the sun's atmosphere are called the chromosphere and the corona.

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The corona is actually hotter than the photosphere at temperatures of 1 to 2 million degrees Celsius.

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The corona is visible to the naked eye during solar eclipses.

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Remember the dark spots, or sunspots, that Galileo studied with his telescope?

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Well, sunspots are dark, cool areas of the sun's surface where charged particles are emitted.

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The sunspot only looks dark relative to the brightness of the rest of the sun,

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The sunspot only looks dark relative to the brightness of the rest of the sun,

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but it's still pretty hot, 4,000 degrees Celsius hot.

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The average sunspot is about the same diameter of the Earth.

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Sunspots generate some of the most violent storms in the solar system.

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When a sunspot erupts, we call this a solar flare.

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Solar flares are some of the biggest explosions in the solar system.

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When a solar flare occurs, gas heat of more than tens of thousands of degrees

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and energy surpassing billions of atomic bombs is hurled out from the sun.

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Another type of explosion is the CME, or coronal mass ejection.

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These explosions can reach speeds of millions of kilometers per hour

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and can reach the Earth in just three days.

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Both solar flares and CMEs can be very disruptive to human activity on Earth and in space

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as these storms, we call them solar storms, travel to the Earth.

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You know, Dan, just like meteorologists use satellites to predict weather here on Earth,

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NASA uses satellites to predict solar storms.

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Wait a minute. You're saying that in the future we'll talk about solar storms

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like we talk about storms here on Earth?

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We sure will.

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Hmm. Predicting the storms of the future.

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This just in America, things are brewing up inside sunspots.

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There'll be a high energy burst of x-rays flowing from the sun.

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For you people on the moon, SPF 3000 will come in handy

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as the pulse should be hitting moon-based Norbert right now.

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Solar storms have caused disruptions in our communications and power supplies.

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For instance, in 1989, a solar storm knocked out electric power in Quebec, Canada.

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Six million homes were without power for nine hours as a result of magnetic solar storms.

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Predicting solar storms has huge benefits to us here on Earth.

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If power companies could receive earlier storm alerts,

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they could minimize damage and power outages.

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So what is NASA doing to warn us about these solar storms?

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To learn more about the sun-Earth connection and how it affects us,

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I'll show you a really cool website you can do at home or at school.

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In the meantime, I'm going to head to NASA Goddard Space Flight Center in Greenbelt, Maryland

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to talk with astronomer Dr. Sten Odenwall.

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He runs Ask the Space Scientist with NASA's image satellite program.

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What are some forms of electromagnetic radiation?

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How can satellites help researchers monitor the sun?

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Why is it important to track solar storms as they approach the Earth?

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If you want to get a clear view of what the sun is doing,

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you have to get above the Earth's distorting atmosphere.

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So we use satellites to gather the data that we need to understand how the sun works.

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The sun radiates at all energy levels.

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Radiation is energy that travels and spreads out as it goes.

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There are different types of radiation. Let me show you.

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Visible light that comes from a lamp in your house

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or radio waves that come from a radio station are two types of radiation.

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Other examples of radiation are microwaves that cook popcorn in a few minutes,

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infrared light, which restaurants use to keep food warm,

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ultraviolet light, which causes our skin to burn,

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X-rays, which help doctors look at your bones,

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and gamma rays, which are emitted from radioactive materials.

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So, Jennifer, let's apply this information to the sun.

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As Eric stated earlier, the photosphere emits energy primarily in visible light,

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while the lower corona emits energy in extreme ultraviolet light

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and the upper corona in X-rays.

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By zeroing in on one particular light energy,

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we can study the various parts of the sun and how they interact.

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Okay, Dr. Odenwald, how can satellites help us to monitor and observe the sun?

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With satellite technology, you can look at the sun 24 hours a day.

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We can put satellites outside of the Earth's atmosphere

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to collect valuable data from the sun

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and to act as early warning devices against solar storms.

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Three important satellites that monitor the sun

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and provide us with real-time data are the SOHO, ACE, and IMAGE satellites.

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If you'd like to learn more about the SOHO satellite,

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Dr. Terry Kuchera, one of our researchers at NASA Goddard, has all the information.

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Great, great. Hey, Terry.

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Hi, Jennifer.

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SOHO, or the Solar and Heliospheric Observatory,

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has a dozen different instruments which observe the sun 24 hours a day

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without interference from the Earth's atmosphere.

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These instruments record the activity of a solar corona, the photosphere,

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and even study the sun's deep interior.

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SOHO has telescopes on board that take pictures of the sun in ultraviolet light.

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Also, SOHO can give us a two- to three-day early warning of coming solar storms

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that can affect the Earth's magnetic field.

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That's really cool. Thanks, Terry.

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Oh, you're welcome.

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So what's next, Dan?

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The second satellite is ACE, the Advanced Composition Explorer.

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ACE operates like an ocean buoy that measures the density, temperature,

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magnetism, and speed of the solar wind as it passes by.

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If a solar storm is headed our way, ACE will detect it

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and give us 30 to 45 minutes warning that a storm is about to hit the Earth.

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Cool. So how do NASA researchers then analyze and interpret the data?

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One way we can analyze and interpret data is by graphing them.

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The graph shows the speed of the solar wind changing as it blows by the ACE satellite.

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The title of this graph is Solar Wind Speed.

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The horizontal axis, or x-axis, represents the number of days in September of 2000.

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And the vertical axis, or y-axis, represents the speed of the wind in kilometers per second.

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Okay, Sten. It looks like the speed of the solar wind ranged from 350 kilometers per second

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to 800 kilometers per second during the month of September.

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You're right, Jennifer.

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On September the 18th, the solar wind reached speeds of 800 kilometers per second,

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or about 1.7 million miles an hour.

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But most of the time, the solar wind averaged around 450 kilometers per second.

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From the analysis of this graph, we can determine how long it took the solar wind to reach the Earth's atmosphere.

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That's amazing, Sten.

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Now, besides SOHO and ACE, you mentioned a third satellite, IMAGE.

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Is that the one you're working with?

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That's right, Jennifer. IMAGE, which means Imager for Magnetosphere to Aurora Global Exploration.

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And it's a satellite that orbits the Earth and measures the locations and changes

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in the invisible clouds of particles that surround the Earth in space.

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You probably already know one of these cloud systems, the Van Allen belts.

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Astronauts and satellites avoid these belts because of their radiation hazard.

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There is also a separate collection of particles called the ring current,

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which appears and disappears whenever the Earth gets whacked by a solar storm.

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Another one of these clouds, called the plasmasphere, is actually a part of our own atmosphere.

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It extends over 10,000 miles above the Earth.

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The IMAGE satellite lets us watch these different families of clouds change.

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IMAGE helps us understand how solar storms can cause problems for our technology in space

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and the health of our astronauts working there, too.

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More importantly, it helps scientists improve our ability to forecast space weather.

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Wow, I realized the sun was critical to sustain life here on Earth.

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But I guess I never realized the devastating effects the sun could have on us.

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It's amazing, Jennifer.

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Solar storms have caused billions of dollars worth of satellite damage in the last 20 years.

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They have caused blackouts

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and will always be a hazard for astronauts working in space.

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Satellites like SOHO, ACE, and IMAGE, and their replacements,

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will be our only means of keeping track of when the next storm hits Earth's magnetic field.

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If students would like to learn more about how the sun works and about solar storms,

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they can visit the Sun-Earth Day website,

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which was developed by the Sun-Earth Connection Education Forum,

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in collaboration with the NASA Office of Space Science.

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Thank you so much, Dr. Odenwald.

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You know, Dan has been working on some websites about the sun.

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Let's go see what he's up to.

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Welcome to my domain.

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We've got a cool activity on our NASA Connect website

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to help you explore problems related to solar weather.

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It's a PBL, or Problem-Based Learning Activity.

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Here's the problem you and your classmates will try to solve.

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You are the secretary of your club

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and have used a pager and a cell phone to let your committee know about the time for your next meeting.

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When no one responded, you made several calls the next day

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and found that no one got your messages.

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You want to find out what went wrong?

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Go to Dan's domain on the NASA Connect website

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to find out more about how to solve the problem.

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You'll also find a link to NASA Goddard's Sun-Earth Connection Education Forum

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Here, you'll find a lot of great resources to help you in your exploration.

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One of the resources is a guide to space weather.

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In it, you'll see images and information about such things as sunspots,

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solar cycles, solar flares, auroras, and more.

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Check out the links to the Eclipse Archive.

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It gives detailed information for all eclipses of the sun and moon from 2001 through 2005.

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And teachers, there's an excellent educator's guide that you can download from the website.

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This guide is designed to provide educators with a quick reference to materials and resources

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that are useful for understanding sun and earth connections.

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The web-based activity I've just talked about could be used for collaborating

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with other NASA Connect classrooms around the world.

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epals.com has a website that provides a meeting place and collaborative tools

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that over 4 million teachers and students can use to connect with other classrooms

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and work on projects like this together.

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All you have to do is have your teacher create a profile for your class.

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Make sure to include the keywords NASA Connect in your profile.

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By using EPAL's search tool, your teacher can easily find other NASA Connect classrooms.

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You'll also find free teacher-monitored email for students as well as collaborative tools

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like moderated discussion boards and chat rooms.

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That's it for my domain. Now back to the Maryland Science Center.

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Okay, let's review. We've learned about the basic parts of the sun.

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We've learned how research scientists study the sun with different types of light radiation.

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We've also learned that satellites provide us with this information.

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Right, but what if we could see the events leading up to solar storms?

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Dr. Michelle Larson from the University of California at Berkeley has the scoop.

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What is the goal of the HESI satellite?

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What is the goal of the HESI satellite?

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When do solar flares occur on the sun?

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How do solar flares have a direct effect on the Earth's atmosphere?

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Hi, I'm Michelle Larson and I'm an astrophysicist.

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An astrophysicist is a researcher who studies physics in space.

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I'm here at Vandenberg Air Force Base in California with the HESI satellite.

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Let's take a look.

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HESI, or High Energy Solar Spectroscopic Imager,

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is designed to learn more about the basic physical processes that occur in solar flares.

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Teams of astrophysicists and engineers work together to decide what kinds of observations HESI will make

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and what kinds of scientific instrumentation will be required.

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The HESI teams will achieve their goals by taking pictures of solar flares in the X-ray and gamma-ray radiation range.

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What is a solar flare?

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Well, remember when Eric told you that solar flares are the biggest explosions in the solar system?

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A solar flare occurs when magnetic energy that builds up in the solar atmosphere is suddenly released.

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Charged particles, such as electrons, protons, and heavier ions, travel away from the sun along magnetic field lines.

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Others move towards the surface of the sun and emit X-ray and gamma-ray radiation as they slow down.

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Flares produce all forms of radiation, from radio waves and visible light to X-rays and gamma rays.

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Why study solar flares?

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The biggest flares are as powerful as billions of hydrogen bombs exploding at the same time.

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We still don't know what triggers them or how they release so much energy in such a short time.

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But solar flares have a direct effect on the Earth's upper atmosphere.

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For instance, long-distance radio communications can be disrupted by the effect of flares on the Earth's ionosphere,

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that is a part of the Earth's atmosphere.

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In addition, energetic particles accelerated in solar flares that escape into interplanetary space

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are dangerous to astronauts outside the protection of the Earth's atmosphere and magnetic field,

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and also to electronic instruments in space.

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Where do solar flares occur?

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Solar flares occur in the solar atmosphere.

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Inside a flare, the temperature is roughly 10 times hotter than the corona

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and can be as high as 100 million degrees Celsius.

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The frequency of solar flares varies with the 11-year solar cycle.

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At solar minimum, very few flares occur.

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As the Sun approaches the maximum part of its cycle, they occur more and more frequently.

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Let me show you on this graph.

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Let's look at the graph of actual solar flare data from 1990 to 2001.

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The title of this graph is number of solar flares versus years.

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The horizontal axis, or x-axis, represents years,

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and the vertical axis, or y-axis, represents the total number of flares recorded.

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From the graph, we can see that we have a solar maximum in 1990 and one in 2001.

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We have a solar minimum at some point between 1995 and 1996.

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This graph shows us that the Sun does have a solar cycle, which is about 11 years.

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From this graph, we can predict when the next solar maximum and minimum will occur.

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How do you study solar flares?

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Well, it's actually very difficult to study the high-energy X-rays and gamma rays emitted during solar flares.

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To solve this problem, HESI uses a very unique method.

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HESI will obtain pictures of solar flares within the X-ray and gamma ray range

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by using pairs of metal grids to cast shadows onto detectors.

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Each grid is a bit like a fine screen, but with lines running in only one direction, like jail bars.

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The solid slats block radiation, and the open slits allow radiation to pass through.

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As the satellite rotates at about 15 times per minute,

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the grids will allow high-energy X-rays and gamma rays from different parts of the Sun

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to sometimes pass through and sometimes not, depending on how the slats are oriented.

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The HESI detectors will measure the energies of the X-rays and gamma rays that get through

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and will record how things change as the satellite, and therefore the grids, rotate.

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This is enough information to figure out where the radiation came from on the Sun.

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This information will be transmitted to the ground,

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where HESI scientists will use it in their computers to make pictures of flares in X-rays and gamma rays.

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It is like putting together the pieces of a puzzle to figure out what the picture is.

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The special way HESI will measure high-energy radiation from the Sun,

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combined with the way scientists will analyze the data,

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will allow us to study the Sun in a way never before attempted.

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Why will HESI observe the solar flares in the X-ray and gamma ray range?

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We know that light emitted in the X-ray and gamma ray range

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shows different events than that emitted in the visible light range.

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High-energy X-rays and gamma rays carry the most direct information available

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about the energetic particle activity on the Sun that occurs in solar flares.

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With the help of HESI, we will be able to anticipate solar flares,

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and HESI will aid in understanding energetic events throughout the universe.

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Thanks, Michelle.

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Say, how would you like to plot out the cycles of solar flares?

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Students at Hardy Middle School in Washington, D.C. will show you how.

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Check out my nose.

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Hi, we're from Hardy Middle School.

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Here in Georgetown, Washington, D.C.

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NASA Connect has asked us to show you this hands-on activity.

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It's called X-ray candles.

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Solar flares on your birthday.

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Here are the main objectives.

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You'll discover the solar cycle through an investigation of solar X-ray flares.

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You'll record the total number of flares in your birth month over an 11-year period.

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You'll compute the percentage of M-class flares that occur.

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You'll graph your findings to help you identify the long-term pattern of flare activity on the Sun.

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And you'll incorporate problem-solving strategies in a real-life application.

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The list of materials you'll need for this activity can be downloaded from the NASA Connect website.

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The class will be divided into groups according to their birth month.

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Teachers will provide each group with solar flare data for the corresponding birth month,

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and each student with a calculator, graph paper, and student data charts.

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Good morning, class.

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Today, your job is to plot and analyze solar flare data from a satellite

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and determine the solar cycle of the Sun.

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First, add the total number of flares that occurred in your birth month for each year.

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Record that number in the last column of each row of the solar flare data sheet.

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Second, add all the numbers in the last column of the solar flare data sheets

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to determine the total number of flares in your birth month for each year.

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Record that number for each year in the box at the bottom of each page of the solar flare data sheet.

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Next, add the total number of M-class flares in your birth month for each year.

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Record the total number of M-class flares for each year in the box

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at the bottom-middle of each page of the solar flare data sheet.

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What do you get for your birth month?

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14.

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Groups will need to collaborate with each other

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to get information on the total number of flares and M-class flares for all months in each year.

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Record the data on the student data chart.

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Record the total number of flares and M-class flares for each year on the student chart.

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From this data, compute the percentage of M-class flares for each year

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by using the equation M-class flares divided by total number of flares multiplied by 100.

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Students will then plot the percentage of M-class flares versus year.

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Okay, why is it important for researchers and scientists to know

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when solar maximums and solar minimums will occur?

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Connor.

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So they know when solar storms will hit the Earth.

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Anybody else?

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Allison.

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So they can warn us if the electricity will go out in our homes.

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Special thanks to the AIAA National Capital Section

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and the AIAA mentors from the University of Maryland who helped us with this show.

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Thank you. We had a great experience.

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And we encourage teachers to visit our website

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to learn more about the AIAA Mentorship Program in your area.

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Well, that wraps up another episode of NASA Connect.

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We'd like to thank everyone who helped make this program possible.

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Got a comment, question, or suggestion?

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Well, email them to connect at lark.nasa.gov.

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Or pick up a pen and mail them to NASA Connect,

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NASA Center for Distance Learning,

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NASA Langley Research Center, Mail Stop 400, Hampton, Virginia, 23681.

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Teachers, if you would like a videotape of this program and the accompanying lesson guide,

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check out the NASA Connect website.

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From our site, you can link to the NASA Educator Resource Center Network.

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These centers provide educators free access to NASA products, like NASA Connect.

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Or from our site, you can link to CORE,

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the NASA Central Operation of Resources for Educators.

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View this and past NASA Connect shows on your computer.

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Visit NASA Quest at quest.nasa.gov.

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So until next time, stay connected to math, science, technology, and NASA.

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See you then. Bye.

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NASA Jet Propulsion Laboratory, California Institute of Technology

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NASA Jet Propulsion Laboratory, California Institute of Technology

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NASA Jet Propulsion Laboratory, California Institute of Technology

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NASA Jet Propulsion Laboratory, California Institute of Technology

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NASA Jet Propulsion Laboratory, California Institute of Technology

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NASA Jet Propulsion Laboratory, California Institute of Technology