So you’ve played with lenses, mirrors, and built an optical bench. Want to make a real telescope? In this experiment, you’ll build a Newtonian and a refractor telescope using your optical bench.
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Telescopes and binoculars are pretty useless unless you know where to point them. I am going to show you some standard constellations and how to find them in the night sky, so you’ll never be lost again in the ocean of stars overhead. We’re going to learn how to go star gazing using planetarium software, and how to customize to your location in the world so you know what you’re looking at when you look up into the sky tonight!
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This is a recording of a recent live class I did with an entire high school astronomy class. I’ve included it here so you can participate and learn, too!
Light is energy that can travel through space. How much energy light has determines what kind of wave it is. It can be visible light, x-ray, radio, microwave, gamma or ultraviolet. The electromagnetic spectrum shows the different energies of light and how the energy relates to different frequencies, and that’s exactly what we’re going to cover in class. We’re going to talk about light, what it is, how it moves, and it’s generated, and learn how astronomers study the differences in light to tell a star’s atmosphere from millions of miles away.
I usually give this presentation at sunset during my live workshops, so I inserted slides along with my talk so you could see the pictures better. This video below is long, so I highly recommend doing this with friends and a big bowl of popcorn. Ready?
This is a recording of a recent live teleclass I did with thousands of kids from all over the world. I’ve included it here so you can participate and learn, too!
We’re ready to deal with the topic you’ve all been waiting for! Join me as we find out what happens to stars that wander too close, how black holes collide, how we can detect super-massive black holes in the centers of galaxies, and wrestle with question: what’s down there, inside a black hole?
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This is a recording of a recent live teleclass I did with thousands of kids from all over the world. I've included it here so you can participate and learn, too
Our solar system includes rocky terrestrial planets (Mercury, Venus, Earth, and Mars), gas giants (Jupiter and Saturn), ice giants (Uranus and Neptune), and assorted chunks of ice and dust that make up various comets and asteroids.
Did you know you can take an intergalactic star tour without leaving your seat? To get you started on your astronomy adventure, I have a front-row seat for you in a planetarium-style star show. I usually give this presentation at sunset during my live workshops, so I inserted slides along with my talk so you could see the pictures better. This video below is long, so I highly recommend doing this with friends and a big bowl of popcorn. Ready?
This lab is a physical model of what happens on Mercury when two magnetic fields collide and form magnetic tornadoes.
You’ll get to investigate what an invisible magnetic tornado looks like when it sweeps across Mercury.
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Using the position of the Sun, you can tell what time it us by making one of these sundials. The Sun will cast a shadow onto a surface marked with the hours, and the time-telling gnomon edge will align with the proper time.
In general, sundials are susceptible to different kinds of errors. If the sundial isn’t pointed north, it’s not going to work. If the sundial’s gnomon isn’t perpendicular, it’s going to give errors when you read the time. Latitude and longitude corrections may also need to be made. Some designs need to be aligned with the latitude they reside at (in effect, they need to be tipped toward the Sun at an angle). To correct for longitude, simply shift the sundial to read exactly noon when indicated on your clock. This is especially important for sundials that lie between longitudinal standardized time zones. If daylight savings time is in effect, then the sundial timeline must be shifted to accommodate for this. Most shifts are one hour.
Today you get to concentrate light, specifically the heat, from the Sun into a very small area. Normally, the sunlight would have filled up the entire area of the lens, but you’re shrinking this down to the size of the dot.
Magnifying lenses, telescopes, and microscopes use this idea to make objects appear different sizes by bending the light. When light passes through a different medium (from air to glass, water, a lens…) it changes speed and usually the angle at which it’s traveling. A prism splits incoming light into a rainbow because the light bends as it moves through the prism. A pair of eyeglasses will bend the light to magnify the image.
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Scientists do experiments here on Earth to better understand the physics of distant worlds. We’re going
to simulate the different atmospheres and take data based on the model we use.
Each planet has its own unique atmospheric conditions. Mars and Mercury have very thin atmospheres, while Earth has a decent atmosphere (as least, we like to think so). Venus’s atmosphere is so thick and dense (92 times that of the Earth’s) that it heats up the planet so it’s the hottest rock around. Jupiter and Saturn are so gaseous that it’s hard to tell where the atmosphere ends and the planet starts, so scientists define the layers based on the density and temperature changes of the gases. Uranus and Neptune are called ice giants because of the amounts of ice in their atmospheres.
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Today you get to learn how to read an astronomical chart to find out when the Sun sets, when twilight ends, which planets are visible, when the next full moon occurs, and much more. This is an excellent way to impress your friends.
The patterns of stars and planets stay the same, although they appear to move across the sky nightly, and different stars and planets can be seen in different seasons.
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Kepler’s Laws of planetary orbits explain why the planets move at the speeds they do. You’ll be making a scale model of the solar system and tracking orbital speeds.
Kepler’s 1st Law states that planetary orbits about the Sun are not circles, but rather ellipses. The Sun lies at one of the foci of the ellipse. Kepler’s 2nd Law states that a line connecting the Sun and an orbiting planet will sweep out equal areas in for a given amount of time. Translation: the further away a planet is from the Sun, the slower it goes.
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How do astronomers find planets around distant stars? If you look at a star through binoculars or a telescope, you’ll quickly notice how bright the star is, and how difficult it is to see anything other than the star, especially a small planet that doesn’t generate any light of its own! Astronomers look for a shift, or wobble, of the star as it gets gravitationally “yanked” around by the orbiting planets. By measuring this wobble, astronomers can estimate the size and distance of larger orbiting objects.
Doppler spectroscopy is one way astronomers find planets around distant stars. If you recall the lesson where we created our own solar system in a computer simulation, you remember how the star could be influenced by a smaller planet enough to have a tiny orbit of its own. This tiny orbit is what astronomers are trying to detect with this method.
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It just so happens that the Sun’s diameter is about 400 times larger than the Moon, but the Moon is 400 times closer than the Sun. This makes the Sun and Moon appear to be about the same size in the sky as viewed from Earth. This is also why the eclipse thing is such a big deal for our planet.
You’re about to make your own eclipses as you learn about syzygy. A total eclipse happens about once every year when the Moon blocks the Sun’s light. Lunar eclipses occur when the Sun, Moon, and Earth are lined up in a straight line with the Earth in the. Lunar eclipses last hours, whereas solar eclipses last only minutes.
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A meteoroid is a small rock that zooms around outer space. When the meteoroid zips into the Earth’s atmosphere, it’s now called a meteor or “shooting star”. If the rock doesn’t vaporize en route, it’s called a meteorite as soon as it whacks into the ground. The word meteor comes from the Greek word for “high in the air.”
Meteorites are black, heavy (almost twice the normal rock density), and magnetic. However, there is an Earth-made rock that is also black, heavy, and magnetic (magnetite) that is not a meteorite. To tell the difference, scratch a line from both rocks onto an unglazed tile. Magnetite will leave a mark whereas the real meteorite will not.
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You are going to start observing the Sun and tracking sunspots across the Sun using one of two different kinds of viewers so you can figure out how fast the Sun rotates. Sunspots are dark, cool areas with highly active magnetic fields on the Sun’s surface that last from hours to months. They are dark because they aren’t as bright as the areas around them, and they extend down into the Sun as well as up into the magnetic loops.
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What comes to mind when you think about empty space? (You should be thinking: “Nothing!”) One of Einstein’s greatest ideas was that empty space is not actually nothing – it has energy and can be influenced by objects in it. It’s like the T-shirt you’re wearing. You can stretch and twist the fabric around, just like black holes do in space.
Today, you will get introduced to the idea that gravity is the structure of spacetime itself. Massive objects curve space. How much space curves depends on how massive the object is, and how far you are from the massive object.
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Have you ever wondered why the sky is blue? Or why the sunset is red? Or what color our sunset would be if we had a blue giant instead of a white star? This lab will answer those questions by showing how light is scattered by the atmosphere.
Particles in the atmosphere determine the color of the planet and the colors we see on its surface. The color of the star also affects the color of the sunset and of the planet.
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A binary system exists when objects approach each other in size (and gravitational fields), the common point they rotate around (called the center of mass) lies outside both objects and they orbit around each other. Astronomers have found binary planets, binary stars, and even binary black holes.
The path of a planet around the Sun is due to the gravitational attraction between the Sun and the planet. This is true for the path of the Moon around the Earth, and Titan around Saturn, and the rest of the planets that have an orbiting moon.
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You’re going to use a compass to figure out the magnetic lines of force from a magnet by mapping the two different poles and how the lines of force connect the two. A magnetic field must come from a north pole of a magnet and go to a south pole of a magnet (or atoms that have turned to the magnetic field.)
Compasses are influenced by magnetic lines of force. These lines are not necessarily straight. When they bend, the compass needle moves. The Earth has a huge magnetic field. The Earth has a weak magnetic force. The magnetic field comes from the moving electrons in the currents of the Earth’s molten core. The Earth has a north and a south magnetic pole which is different from the geographic North and South Pole.
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One common misconception is that the seasons are caused by how close the Earth is to the Sun. Today you get to do an experiment that shows how seasons are affected by axis tilt, not by distance from the Sun. And you also find out which planet doesn’t have sunlight for 42 years.
The seasons are caused by the Earth’s axis tilt of 23.4o from the ecliptic plane.
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If you could stand on the Sun without being roasted, how much would you weigh? The gravitational pull is different for different objects. Let’s find out which celestial object you’d crack the pavement on, and which your lightweight toes would have to be careful about jumping on in case you leapt off the planet.
Weight is nothing more than a measure of how much gravity is pulling on you. Mass is a measure of how much stuff you’re made out of. Weight can change depending on the gravitational field you are standing in. Mass can only change if you lose an arm.
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We’re going to do a chemistry experiment to simulate the heat generated by the internal core of Neptune by using a substance used for melting snow mixed with baking soda.
Calcium chloride splits into calcium ions and chloride ions when it is mixed with water, and energy is released in the form of heat. The energy released comes from the bond energy of the calcium chloride atoms, and is actually electromagnetic energy. When the calcium ions and chloride ions are floating around in the warm solution, they are free to interact with the rest of the ingredients added, like the sodium bicarbonate, to form carbon dioxide gas and sodium chloride (table salt).
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Greetings and welcome to the study of astronomy! This first lesson is simply to get you excited and interested in astronomy so you can decide what it is that you want to learn about astronomy later on.
We’re going to cover a lot in this presentation, including: the Sun, an average star, is the central and largest body in the solar system and is composed primarily of hydrogen and helium.
The solar system includes the Earth, Moon, Sun, seven other planets and their satellites (moons) and smaller objects such as asteroids and comets. The structure and composition of the universe can be learned from the study of stars and galaxies. Galaxies are clusters of billions of stars, and may have different shapes. The Sun is one of many stars in our own Milky Way galaxy. Stars may differ in size, temperature, and color.
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Helioseismology is the study of wave oscillations in the Sun. By studying the waves, scientists can tell what’s going on inside the Sun. It’s like studying earthquakes to learn what’s going on inside the earth. The Sun is filled with sound, and studying these sound waves is currently the only way scientists can tell what’s going on inside, since the light we see from the Sun is just from the upper surface.
Molecules are vibrating back and forth at fairly high rates of speed, creating waves. Energy moves from place to place by waves. Sound energy moves by longitudinal waves (the waves that are like a slinky). The molecules vibrate back and forth, crashing into the molecules next to them, causing them to vibrate, and so on and so forth. All sounds come from vibrations.
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Jupiter not only has the biggest lightning bolts we’ve ever detected, it also shocks its moons with a charge of 3 million amps every time they pass through certain hotspots. Some of these bolts are cause by the friction of fast-moving clouds. Today you get to make your own sparks and simulate Jupiter’s turbulent storms.
Electrons are too small for us to see with our eyes, but there are other ways to detect something’s going on. The proton has a positive charge, and the electron has a negative charge. Like charges repel and opposite charges attract.
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On a clear night when Jupiter is up, you’ll be able to view the four moons of Jupiter (Europa, Ganymede, Io, and Callisto) and the largest moon of Saturn (Titan) with only a pair of binoculars. The question is: Which moon is which? This lab will let you in on the secret to figuring it out.
You get to learn how to locate a planet in the sky with a pair of binoculars, and also be able to tell which moon is which in the view.
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If you want to get from New York to Los Angeles by car, you’d pull out a map. If you want to find the nearest gas station, you’d pull out a smaller map. What if you wanted to find our nearest neighbor outside our solar system? A star chart is a map of the night sky, divided into smaller parts (grids) so you don’t get too overwhelmed. Astronomers use these star charts to locate stars, planets, moons, comets, asteroids, clusters, groups, binary stars, black holes, pulsars, galaxies, planetary nebulae, supernovae, quasars, and more wild things in the intergalactic zoo.
How to find two constellations in the sky tonight, and how to get those constellations down on paper with some degree of accuracy.
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The Moon appears to change in the sky. One moment it’s a big white circle, and next week it’s shaped like a sideways bike helmet. There’s even a day where it disappears altogether. So what gives?
The Sun illuminates half of the Moon all the time. Imagine shining a flashlight on a beach ball. The half that faces the light is lit up. There’s no light on the far side, right? For the Moon, which half is lit up depends on the rotation of the Moon. And which part of the illuminated side we can see depends on where we are when looking at the Moon. Sound complicated? This lab will straighten everything out so it makes sense.
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Does it rain on the Sun? The answer to this is yes, however, it is not water that falls but very hot plasma. On July 19, 2012, there was an eruption on the Sun that produced a massive burst of solar wind and magnetic fields and released into Space. This eruption also produced a powerful solar flare. After that, a phenomenon known as coronal rain occurred. Corona Rain occurs occurs when hot plasma in the corona cools and condenses in strong magnetic fields, usually associated with regions that produce solar flares. The plasma condenses and slowly falls back to the solar surface.
The electrons, protons and ions in the rain is forced to move along the magnetic loops of the Sun’s surface. As a result, this bright flare highlights matter glowing at a temperature of about 50,000 Kelvin. The entire coronal rain lasted about 10 hours.
Video Credit : http://apod.nasa.gov/apod/ap130226.html
Many wonders are visible when flying over the Earth at night, especially if you are an astronaut on the International Space Station (ISS)! Passing below are white clouds, orange city lights, lightning flashes in thunderstorms, and dark blue seas. On the horizon is the golden haze of Earth’s thin atmosphere, frequently decorated by dancing auroras as the video progresses. The green parts of auroras typically remain below the space station, but the station flies right through the red and purple auroral peaks. You’ll also see solar panels of the ISS around the frame edges. The wave of approaching brightness at the end of each sequence is just the dawn of the sunlit half of Earth, a dawn that occurs every 90 minutes, as the ISS travels at 5 miles per second to keep from crashing into the earth.
Video Credit: Gateway to Astronaut Photography, NASA
The Hubble Space Telescope (HST) zooms around the Earth once every 90 minutes (about 5 miles per second), and in August 2008, Hubble completed 100,000 orbits! Although the HST was not the first space telescope, is the one of the largest and most publicized scientific instrument around. Hubble is a collaboration project between NASA and the ESA (European Space Agency), and is one of NASA’s “Great Observatories” (others include Compton Gamma Ray Observatory, Chandra X-Ray Observatory, and Spitzer Space Telescope). Anyone can apply for time on the telescope (you do not need to be affiliated with any academic institution or company), but it’s a tight squeeze to get on the schedule.
Hubble’s orbit zooms high in the upper atmosphere to steer clear of the obscuring haze of molecules in the sea of air. Hubble’s orbit slowly decays over time and begins to spiral back into Earth until the astronauts bump it back up into a higher orbit.
But how does a satellite stay in orbit? Try this experiment now:
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This is the stuff of dreams, imagination, creativity and innovation.This is especially cool for parents to have their children witness something “out of this world” live as it happens. This is American science education at its absolute finest.
NASA’s Jet Propulsion Laboratory (JPL) has done it again, BIG TIME!
In normal fashion for JPL in Pasadena, this was no normal, everyday kind of landing, as Curiosity will blast into the Martian atmosphere at 13,000 miles per hour and in a death-defying “Seven Minutes of Terror” come to a soft landing on Mars. Fingers and toes were crossed. And, due to its heavy weight, it will not land like Spirit and Opportunity did about 8 years ago landing in cushioned, inflated air bags that looks like giant raspberries. Curiosity was lowered to the surface under a rocket-powered sky-crane, never before attempted by any spacecraft. Mars Science Laboratory Curiosity is the most sophisticated and complex robotic spacecraft ever built.
Even now that this event has happened, you can witness this history-making event through these special NASA TV video along with millions of people around the world.
Curiosity was launched on an Atlas V rocket from Cape Canaveral on November 26, 2011:
Some folks may have heard that there was a problem anticipated with the transmission of the landing telemetry (radio signal), possibly taking hours before we would know what happened during the landing. That problem was with America’s Mars Odyssey spacecraft orbiting Mars (along with America’s Mars Reconnaissance Orbiter and Europe’s Mars Express Orbiter). A “reaction wheel” that helps control Mars Odyssey’s orbital path location had problems, that could have impacted its ability to receive and relay the telemetry as it happens. The week before landing, JPL engineers successfully corrected the issue, putting Mars Odyssey back on course to directly receive the landing telemetry and beam it back to Earth as it is happening.
Newsflash! Curiosity has successfully landed on the surface of Mars!
Bear in mind that the transmission time from Mars to Earth will be about 14 minutes at the speed of light, so Curiosity will have experienced the Seven Minutes of Terror and landed before we get the signals from Mars. Hold your breath and wish Curiosity the best as you watch these videos!
Here are some of the first images:
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More images are being posted by NASA here: Mars Science Laboratory Image Gallery
Aurora, or ‘northern lights’, is the natural light display in the sky in northern regions like Canada, Alaska, and northern Eurpoean countries that have had people puzzled for centuries as to what exactly they were, and how the light displays were made. Here’s a rare view of the aurorae taken from the International Space Station:
Auroras (or aurorae) happen about 50 miles up, when solar wind hits particles in the Earth’s atmosphere. When charged particles from the solar wind hit the Earth’s magnetosphere (a magnetic field that extends far beyond the Earth’s surface and protects us from solar wind), they are funneled by the Earth’s magnetic field. When these highly charged particles from the sun hit a molecule in our atmosphere, they give off a photon. The green and brownish-red colors come from oxygen and the blue and red are from nitrogen.
In northern latitudes, the aurora borealis was named after the Roman goddess of dawn (Aurora) and the Greek name for the north wind (Boreas). In the south, the aurora australis (or the southern lights) appear anytime the northern lights are visible. This effect is also seen on other planets like Jupiter and Saturn.
Did you know you can create a compound microscope and a refractor telescope using the same materials? It’s all in how you use them to bend the light. These two experiments cover the fundamental basics of how two double-convex lenses can be used to make objects appear larger when right up close or farther away.
Things like lenses and mirrors can bend and bounce light to make interesting things, like compound microscopes and reflector telescopes. Telescopes magnify the appearance of some distant objects in the sky, including the moon and the planets. The number of stars that can be seen through telescopes is dramatically greater than can be seen by the unaided eye.
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If your kid is crazy for Astronomy, get your hands on a $25 copy of Guy Ottewell’s Astronomical Calendar. You won’t find a better, more complete yearly almanac of astronomy anywhere. (In fact, most sources use Ottewell’s information in their publications.)
If a telescope is in your near future, here are a few of my personal recommendations. (Please note that I do not sell any of these telescopes, nor do I get paid for posting these links. Think of this as a sneak peek into my personal collection.)
You might be curious about how to observe the sun safely without losing your eyeballs. There are many different ways to observe the sun without damaging your eyesight. In fact, the quickest and simplest way to do this is to build a super-easy pinhole camera that projects an image of the sun onto an index card for you to view.
CAUTION: DO NOT LOOK AT THE SUN THROUGH ANYTHING WITH LENSES!!
This simple activity requires only these materials:
Mars is coated with iron oxide, which not only covers the surface but is also present in the rocks made by the volcanoes on Mars.
Today you get to perform a chemistry experiment that investigates the different kinds of rust and shows that given the right conditions, anything containing iron will eventually break down and corrode. When iron rusts, it’s actually going through a chemical reaction: Steel (iron) + Water (oxygen) + Air (oxygen) = Rust
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These are a set of videos made using planetarium software to help you see how the stars and planets move over the course of months and years. See what you think and tell us what you learned by writing your comments in the box below.
You can really feel the Earth rolling around under you as you watch these crazy star trails.
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If you watch the moon, you’d notice that it rises in the east and sets in the west. This direction is called ‘prograde motion’. The stars, sun, and moon all follow the same prograde motion, meaning that they all move across the sky in the same direction.
However, at certain times of the orbit, certain planets move in ‘retrograde motion’, the opposite way. Mars, Venus, and Mercury all have retrograde motion that have been recorded for as long as we’ve had something to write with. While most of the time, they spend their time in the ‘prograde’ direction, you’ll find that sometimes they stop, go backwards, stop, then go forward again, all over the course of several days to weeks.
Here are videos I created that show you what this would look like if you tracked their position in the sky each night for an year or two.
What would happen if our solar system had three suns? Or the Earth had two moons? You can find out all these and more with this lesson on orbital mechanics. Instead of waiting until you hit college, we thought we’d throw some university-level physics at you… without the hard math.
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Ever wonder exactly how far away the planets really are? Here’s the reason they usually don’t how the planets and their orbits to scale – they would need a sheet of paper nearly a mile long!
To really get the hang of how big and far away celestial objects really are, find a long stretch of road that you can mark off with chalk. We’ve provided approximate (average) orbital distances and sizes for building your own scale model of the solar system.
When building this model, start by marking off the location of the sun (you can use chalk or place the objects we have suggested below as placeholders for the locations). Are you ready to find out what’s out there? Then let’s get started.
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After you've participated in the Planetarium Star Show (either live or by listening to the MP3 download), treat your kids to a Solar System Treasure Hunt! You'll need some sort of treasure (I recommend astronomy books or a pair of my favorite binoculars, but you can also use 'Mars' candy bars or home made chocolate chip cookies (call them Galaxy Clusters) instead.
You can print out the clues and hide these around your house on a rainy day. Did you know that I made these clues up myself as a refresher course after the astronomy presentation? Enjoy!
Why does the Sun flare? Unpredictably, our Sun unleashes tremendous flares expelling hot gas into the Solar System that can affect satellites, astronauts, and power grids on Earth. This close up of an active region on the Sun that produced a powerful X-class flare was captured by the orbiting TRACE satellite. The glowing gas flowing around the relatively stable magnetic field loops above the Sun's photosphere has a temperature of over ten million degrees Celsius. These flows occurred after violently unstable magnetic reconnection events above the Sun produced the flare. Many things about solar active regions are not well understood including the presence of dark regions that appear to move inward during the movie.
This is a real video of the sun captured from the Solar Dynamics Observatory:
Astrophysics not only looks at nearby planets and distant stars, it also deals with the center of our solar system: the Sun. Our Sun is not quite a sphere (it’s a little flat on one side), which actually made the initial calculations of Mercury’s orbit incorrect when we estimated it to be a perfect ball. Our Sun is a G-type star, and recent measurements indicate that our Sun is brighter than 85% of the stars in our own galaxy. It takes light about 8 minutes to travel from the Sun to the Earth, meaning that if the Sun were to suddenly and magically disappear, we wouldn’t know about it for 8 minutes.
The Sun is made of hot plasma and is 1.3 million times the size of our Earth. The Sun holds 99% of the mass of our solar system, but only has 1% of the momentum. It’s 74% hydrogen and 24% helium, with trace amounts of oxygen, carbon, iron, and neon. Scientists split the incoming light into a giant 40-foot rainbow and looked for signs of which elements are burning through a special instrument called a spectrometer (you’ll be building one of these in this section) to figure out the Sun’s composition.
With a 15 million oC core, the Sun is not on fire, but rather generates heat by smacking protons together and getting a puff of energy through a process called nuclear fusion. We can’t directly observe the core of the Sun, but we can figure out what’s going on inside by watching the patterns on the surface. You’ll learn more about this in the activity that covers helioseismology. The surface temperature of the Sun is about 5500oC, so it cools considerably when the gases bubble up to the surface.
The Sun rotates differentially, since it’s not solid but rather a ball of hot gas and plasma. The equator rotates faster than the poles, and in one of the experiments in this section, you’ll actually get to measure the Sun’s rotation. This differential rotation causes the magnetic fields to twist and stretch. The Sun has two magnetic poles (north and south) that swap every 11 years as the magnetic fields reach their breaking point, like a spinning top that’s getting tangled up in its own string. When they flip, it’s called “solar maximum,” and you’ll find the most sunspots dotting the Sun at this time.
The video below is taken from the very first images from the National Science Foundation's Daniel Inouye Solar Telescope. Do you see the bubbling, rolling surafe of the sun? The size of onen of the "cells" is about the state of Texas, or the size of France, just to give you an idea of scale.
The telescops is on top of a mountain in Hawaii that has a huge 13 foot mirror (the largest ever used ona solar solar telescope), and it also sits along with all the other instruments, on a 16.5 meter table weighing 100 tons that slowly rotates to track the position of the sun as it travels through the sky.
And if you want to see an image of the sun right now, you can visit SOHO's main page.
Want to safely view the sun yourself? Here's how to do it...
You know you're not supposed to look at the sun, so how can you study it safely? I'm going to show you how to observe the sun safely using a very inexpensive filter. I actually keep one of these in the glove box of my car so I can keep track of certain interesting sunspots during the week!
The visible surface of the sun is called the photosphere, and is made mostly of plasma (remember the grape experiment?) that bubbles up hot and cold regions of gas. When an area cools down, it becomes darker (called sunspots). Solar flares (massive explosions on the surface), sunspots, and loops are all related the sun’s magnetic field. While scientists are still trying to figure this stuff out, here’s the latest of what they do know...
The sun is a large ball of really hot gas - which means there are lots of naked charged particles zipping around. And the sun also rotates, but the poles and the equator move and different speeds (don’t forget – it’s not a solid ball but more like a cloud of gas). When charged particles move, they make magnetic fields (that’s one of the basic laws of physics). And the different rotation rates allow the magnetic fields to ‘wind up’ and cause massive magnetic loops to eject from the surface, growing stronger and stronger until they wind up flipping the north and south poles of the sun (called ‘solar maximum’). The poles flip every eleven years.
There have been several satellites specially created to observe the sun, including Ulysses (launched 1990, studied solar wind and magnetic fields at the poles), Yohkoh (1991-2001, studied x-rays and gamma radiation from solar flares), SOHO (launched 1995, studies interior and surface), and TRACE (launched 1998, studies the corona and magnetic field).
Ok - so back to observing the sun form your own house. Here's what you need to do:
Spectacular images of Jupiter during and after impacts, when over twenty fragments of Comet Shoemaker-Levy 9 smashed into the planet in July 1994. Click here to read more.
This mega-flare was seen being spewed out by the Sun starting at 20:29 CET on 4 November 2003. This video sequence was captured by SOHO’s Extreme ultraviolet Imaging Telescope. Don’t worry about the image being green – it’s just the filter they used in order to see.Click here to read more.
In this video below, astronomers blocked out the sun (seen as a white circle in the center of the red disk) so they could see the action in the corona.
Something every person should do in their lifetime is watch a rocket or space shuttle launch. Since this is getting harder and harder, and most folks don’t live in a convenient area for viewing launches, here’s one of the best launches filmed on video. STS-119 (ISS assembly flight 15A) was a space shuttle mission to the International Space Station (ISS) which was flown by Space Shuttle Discovery during March 2009.
It delivered and assembled the fourth starboard Integrated Truss Segment (S6), and the fourth set of solar arrays and batteries to the station. The launch took place on March 15, 2009, at 7:43 p.m. EDT. Discovery successfully landed on March 28, 2009, at 3:13 p.m. EDT.
Lyman Spitzer was a theoretical physicist and astronomer who worked on star formation and plasma physics. The scape telescope named after him is equipped with infrared imaging capability that enables the telescope to see through dust and gas clouds to reveal what lies underneath.
Spitzer is part of the 1970s idea NASA conceived for the Great Observatories. The idea was to have the Hubble Space Telescope operate in the visible range, Chandra which operates in the x-ray, and Spitzer which operates in the infrared. Here’s an informational video about Spitzer:
Subrahmanyan Chandrasekhar was one of the most careful, thorough, and impressive astronomers in the first part of the 20th century who worked in may different areas of astronomy, making great leaps with his discoveries. He won the Nobel prize for his ideas about when and how to get supernova, which he did while traveling on a boat at age 19! Chandra had a very elegant way of using mathematics to describe atmospheres of planets and stellar structures of galaxies. He was one of the few researchers that is able to teach as well as do his own research.
The Chandra X-Ray Observatory is the third of NASA’s Great Observatories. Chandra looks for high energy X-ray radiation, which appears near supernovae, supermassive black holes and neutron stars. Here’s an video about the telescope itself and how difficult it is to observe x-rays:
Launch and flight teams are in final preparations for the planned Jan. 12, 2005, liftoff from Cape Canaveral Air Force Station, Fla., of NASA’s Deep Impact spacecraft. The mission is designed for a six-month, one-way, 431 million kilometer (268 million mile) voyage. Deep Impact will deploy a probe that essentially will be “run over” by the nucleus of comet Tempel 1 at approximately 37,000 kilometers per hour (23,000 miles per hour). It’s like hitting a comet with something the size of a fridge. Click here to read more.
Galileo was an unmanned spacecraft sent by NASA to study the planet Jupiter and its moons. Named after the astronomer and Renaissance pioneer Galileo Galilei, it was launched on October 18, 1989 by the Space Shuttle Atlantis on the STS-34 mission. It arrived at Jupiter on December 7, 1995, a little more than six years later, via gravitational assist flybys of Venus and Earth.
Galileo conducted the first asteroid flyby, discovered the first asteroid moon, was the first spacecraft to orbit Jupiter, and launched the first probe into Jupiter’s atmosphere.
On September 21, 2003, after 14 years in space and 8 years of service in the Jovian system, Galileo’s mission was terminated by sending the orbiter into Jupiter’s atmosphere at a speed of nearly 50 kilometres per second to avoid any chance of it contaminating local moons with bacteria from Earth. Of particular concern was the ice-crusted moon Europa, which, thanks to Galileo, scientists now suspect harbors a salt water ocean beneath its surface. Click here to read more.
The incredible journey to Saturn and Titan. Click here to read more.
This montage of New Horizons images shows Jupiter and its volcanic moon, Io. The images were taken during the spacecraft’s near-pass of the gas giant in early 2007. Credit: NASA/JHU/APL New Horizons’ voyage through the Jupiter system in 2007 provided a bird’s-eye view of a dynamic planet that has changed since the last close-up looks by NASA spacecraft. Click here to read more.
Enrico Fermi gave physics a give leap as he uncovered many puzzles in quantum mechanics and nuclear physics. Fermi had the rare ability to work with both experimental and theoretical physics who also could do the math and teach students in his spare time. He was awarded the Nobel prize at age 37 for figuring out what happens to the nucleus of an atom when you throw too many neurons at it (this induces radioactivity). Here’s a look at the mission that was named after him:
Kepler was the mind that pulled together the observations of Galileo and the data from Tycho to figure out how the planets moved around the sun.
Although his three laws were not recognized in his day (scoffed was more like it!), these laws are still used in today’s science classes. The Kepler mission launched in March, 2009, and is designed to search for Earth-like planets orbiting other stars. Here’s a video that details the mission:
In 1977, NASA launched two small spacecraft called Voyager 1 and Voyager 2. Weighing only 800 kgs each, they collected a wealth of scientific data and thousands of photographs of the four giant planets in our Solar System. After visiting Jupiter and Saturn, Voyager 1’s trajectory left the ecliptic plane in order to photograph Saturn’s moon Titan. This meant that Voyager 1 would not visit any other planets. However, Voyager 2 continued on to visit Uranus and Neptune. Still today, Voyager 2 is the only spacecraft to have visited these two “ice giants” and their moons.
Both Voyagers are still in operation and providing unprecedented data that engineers and scientists using today to understand space. Both are expected to last until 2020-2025, at which time their atomic battery life will no longer support their electrical systems.
Launched on March 2, 1972, Pioneer 10 was the first spacecraft to travel through the asteroid belt, and the first spacecraft to make direct observations and obtain close-up images of Jupiter. Pioneer 10 is now coasting silently through deep space (its last transmission was in 2003) toward the red star Aldebarran (the eye of Taurus the Bull), a journey of over 2 million years. Originally intended as a 21-month program, this 30-year mission has more than paid for itself with discoveries and science.
Mariner 10 was a robotic space probe launched on 3 November 1973 to fly by the planets Mercury and Venus. It was launched approximately 2 years after Mariner 9 and was the last spacecraft in the Mariner program (Mariner 11 and 12 were re-designated Voyager 1 and Voyager 2). The mission objectives were to measure Mercury’s environment, atmosphere, surface, and body characteristics and to make similar investigations of Venus. Secondary objectives were to perform experiments in the interplanetary medium and to obtain experience with a dual-planet gravity-assist mission.
During its flyby of Venus, Mariner 10 discovered evidence of rotating clouds and a very weak magnetic field.
Mariner 10 flew past Mercury three times in total. Owing to the geometry of its orbit — its orbital period was almost exactly twice Mercury’s — the same side of Mercury was sunlit each time, so it was only able to map 40-45% of Mercury’s surface, taking over 2800 photos. It revealed a more or less moon-like surface. It thus contributed enormously to our understanding of the planet, whose surface had not been successfully resolved through telescopic observation.
This is the actual video of the very first moon landing of the Apollo 11 mission in 1969! Neil Armstrong was the first man to set foot on the moon with his now legendary words “One small step for man, a giant leap for mankind.” This is a truly amazing video. If you think about it, you have orders of magnitude more processing power in your mobile phone than they did in the whole space craft!! Incredible!
This lecture series is from an astronomy course at Ohio State. It’s a 20-week college-level course, so don’t feel like you’ve got to do it all in one night! You’ll learn about the solar system, planets, and universe through a well-organized set of lectures that really brings astronomy, human history, and current technology together. This content is appropriate for advanced students and above.
Why bother offering high school students these college-level classes? Because if you’re like me, you’re always thirsty for more, and you’re not picky about where it comes from. If you learn just one new thing from these astronomy talks, then you are one step further along your science journey and it was worth your time.
You can either download the podcasts to your MP3 player or directly access the MP3 files. There are slides along with the lectures, but don’t feel like you have to use them – the lectures are meaty enough on their own. Ready?
Click here to access Prof. Roger Pogge’s Astro 161 Lectures (Part 1)
Click here to access Prof. Roger Pogge’s Astro 162 Lectures (Part 2)
