Turns out there are as many ways to photograph an eclipse as there are to watch it. With a bit of preparation and the generosity of strangers, I got to experience five of them during Sunday's annular eclipse.

My husband and I drove from the Bay Area up to Mt. Hirz near Lake Shasta which was smack in the middle of the optimal eclipse viewing path. About a mile from the top, we ran into an amateur astronomer named Ben who'd scoped the whole mountain the previous day and decided this was the best spot. He had a telescope, so we stayed with him.

A bit of cloud cover when the eclipse started had us all chewing our fingernails, but then it cleared up–and what a view!

Although I am an admirer of photography, I am not the most skilled practitioner. Flickr, however, is a treasure trove of beautiful images. All the pictures in this post are from photographers kind enough to share their work openly, for the enjoyment of the masses.

To make a hokey pinhole camera like I did, cut a square out of a piece of cardbord, tape aluminum foil over the empty square, and poke a hole in the foil with a pin. Stand with your back to the sun and hold the cardboard so the sun shines directly through the pinhole onto a piece of white paper. (This photographer made three holes, one of which was obviously best.)

photo by stevendamron

A better technique is to replace the pinhole with a pair of binoculars like my husband did. You keep your back to the sun and hold the binoculars in the same position as the pinhole camera and you get a larger, clearer view of the sun on the paper.

photo by jinxmcc

Astronomer Ben's wife had a pair of eclipse viewing glasses that were the best way to see color–the "ring of fire" when the moon is totally inside the sun. You can put these glasses–or a really thick filter, which is the same thing–in front of a camera as well as in front of your eyes. But the sun looks really small.

photo by °Florian

Best of all is an actual telescope. Then you can see sunspots!

photo by Mark Langridge

The fifth, final, and possibly my favorite way to see/photograph the eclipse requires no equipment at all–just some trees. When the sun is a crescent, it shines through the leaves to create hundreds of little crescents on the ground or wall.

photo by niiicedave

Photographing the sun is one thing. But the full mood of an eclipse, with its cool air and dusky light, is difficult to capture. Here's one picture (not from the path of full annularity) that really pulled it off:

photo by jimnista

Hypothetical exoplanet of a brown dwarf star--similar to a future Earth? Credit: Jeff Bryant

Every now and then, when seeing fresh examples of the world's problems, local or global, I take a deep breath, sigh, and think, "In a million years, what difference will it all make?" It may sound fatalistic, and of course current events do matter to our short-timer existences on Earth, but the thought gives me an odd sense of peace and gets me to thinking about the future—the far distant future—of the Earth. It's hard to imagine what the future will bring in ten, a hundred, or even a thousand million years. Where will evolution take life on Earth—including us? How far will human civilization stretch, and what turns will it take? What exciting twists and cliffhangers are in store for the climate? What will be on television?

Some things are a bit easier to predict: what the Sun will do and how the Earth and the Earth-Moon relationship will change.

I ran across a web version of the H.G. Wells novel "The Time Machine" a couple of weeks ago, and re-reading Chapter 11 I was reminded how insightful the story is with regard to visualizing future possibilities. In this chapter, the Time Traveler probes forward in time, going millions of years into the future and arriving in a tidally-locked Earth under a bloated, reddened Sun, with no Moon in the sky. The ocean was calm and cold, sporting only gentle, lazy swells, and the air was considerably less stocked with oxygen than today. Snow peppered the land and ice fringed the sea, and the only ubiquitous sign that life still existed was a green slime that coated the rocks of the shore.

"All the sounds of man, the bleating of sheep, the cries of birds, the hum of insects, the stir that makes the background of our lives – all that was over."

An alien, cold, and pessimistic view of the future? Well—it can hardly be classified as pessimistic; pessimism is an emotion based on the seeming unchangeability of things we can in fact change. But the Earth's future is commanded by forces scarcely within our power to affect.

For one, the Earth's rotation is slowing down. It used to spin much faster—maybe three times as much—but tidal effects of the Moon and Sun have been slowing it down for four and a half billion years. Imagine an eight-hour day, with the Sun crossing from horizon to horizon in about four. Wake up, it's only a couple of hours until lunchtime, and another two ‘til dinner. I got a whole three hours of sleep last night! Ahh!

Where is Earth's spin going? Shakespeare had the answer: "The Moon's an arrant thief…." The momentum of Earth's spin is being slowly siphoned off by the Moon through tidal interaction, which is simultaneously causing the Moon to move farther from the Earth. Once much closer to Earth, even today the Moon continues to inch away into space–quite literally, at less than two inches per year.

So in the very distant future, we can project that the Moon will have moved much farther from the Earth, and the Earth's rotation will have slowed down even more. At some point the Earth's rotation would match the Moon's orbital period and the Earth will become tidally locked with the Moon, always keeping the same face to it, just as the Moon is currently tidal-locked to the Earth.

In H.G. Wells' vision, the far distant future Earth is tidally locked to the Sun, and the Moon is apparently gone. Would this happen? Will there ever be an Earth with an unending day and unending moonless night (depending on your address)? That could happen, but the Moon would have to leave the picture first, perhaps wandering far enough out that a chance gravitational disturbance by another planet would knock it off the edge of its orbit.

The Sun is changing too—has changed, and will continue to change—as the dynamics of its nuclear fuel supply mix shifts. As atomic fusion converts hydrogen into helium, helium to carbon, and so forth, the availability of easily released energy will diminish, causing the core to shrink and heat up, in turn causing the outer layers to inflate, becoming more expansive but also cooler and redder. In the very long run, the outer layers will expand beyond Earth's present orbit.

So there is a future out there that we can be more certain of than the future shaped by human affairs. It's further out in time than the decades or centuries ahead—and frankly further out than H. G. Wells penned in at 30 million years (little will have changed with the length of a day and the mile markers to the Moon in that time, and I believe the Sun won't make much of a fuss for at least a billion, or more).

In the meantime, it's captivating to think what the scenery may be like around the place I stand today, a million or a billion years hence.

M9 Solar Flare of January 23 2012; credit: Solar Dynamics Observatory

Let's see, what's the weather like right now (sticks finger into the air). Speed, 1.2 million miles per hour, density 1.1 protons per cubic centimeter, temperature 200,000 degrees Celsius. Sound a bit extreme? Surely climate change hasn't made things THAT batty. As a matter of fact, conditions have calmed down in the last several hours.

Okay, I'm not talking Earth weather—if I were, we'd all be dead, fast. I'm talking space weather, and a subsidence in its condition following a powerful solar flare whose ejecta struck Earth on Tuesday, causing a strong geomagnetic storm, and some pretty Northern and Southern Lights.

The flare in question, associated with the big sunspot numbered 1402, erupted on January 23rd, launching a coronal mass ejection–a "cantaloupe" of plasma that makes Earth look like a grape. Rated as an M9-class flare, it packed umph just shy of what's necessary for adult "X-class" flaredom, the most power kind.

When it reached us the megablob of plasma struck Earth's magnetic field, causing the geomagnetic storm and a minor list of annoyances (communications interference, for the most part, and some reported concern to an electrical grid operator). On the showier side of solar activity, the storm generated spectacular auroras in high latitudes.

The Sun's magnetic activity—the source of disturbances like flares and oft-associated coronal mass ejections—has been on the rise for the last couple of years, heading for a forecasted peak in activity ("Solar Maximum") in 2013. We're in "storm season," with respect to the Sun's 11-year magnetic activity cycle, so we can expect more, and stronger, flares and geomagnetic storms in the next year or two to come.

Back when I was growing up (1960's) I learned that space is a vacuum, void of the gases we find in Earth's atmosphere. It was a stark picture of emptiness, at least as this child comprehended the data. Sure, sunlight and starlight streams through that vacuum, but other than that, Dr. Science explained, if I took one space-step outside of my personal Mercury space capsule without protection, I'd suffocate and my blood would boil and freeze at the same time—not to mention that I'd get cooked by the dangerous ultraviolet and X-ray radiation shining from the Sun.

Okay, close the Time-Life science series book entitled "Space" and open an astrophysics textbook of my 1960's youth era, and I would have learned that there's more to the vacuum of space than nothing.

Our Sun, a gargantuan fusion bomb that consumes a mass of hydrogen comparable to that of the entire human race each second, continually spews more than just sunlight into the space around it. Hot, electrically charged gas (plasma), mostly hydrogen nuclei and electrons, blended with an accompaniment of magnetic fields, blow outward from the Sun's surface and atmosphere all the time.

That's the solar wind, and its conditions, whether normal or stormy, is what makes space weather. So when you're curious about the weather conditions in the space surrounding Earth and its protective magnetic field, poke your finger skyward and extend your arm—oh—about 50,000 miles…or just go to a space weather website like Spaceweather.com.

The life history cycles of the bay checkerspot butterfly and its host plant, Plantago, don’t match up anymore. When the butterfly eggs hatch, the plant is no longer edible. Photo: kqedquest.

Tomorrow is our summer solstice—the longest day of the year here in the Northern Hemisphere. For folks in the Southern Hemisphere, tomorrow is the winter solstice, the shortest day of the year. The solstices occur thanks to the tilt of the earth. Humans have been recognizing and celebrating the solstices throughout history; Stonehenge is just one example. But we humans are not the only creatures that pay attention to day length. The life cycles of myriad plants and animals are controlled by the length of the day.

Many plants and animals are sensitive to the photoperiod, or day length. As day length grows longer throughout the springtime, many species of plants begin to flower. Other plants are triggered to reproduce when the day length becomes shorter. In these plants, a protein is actually responding to the number of hours of darkness, not to the hours of light. Many animals respond to day length, too. For many bird species, a critical day length initiates their reproductive maturation and is their cue to begin migrating. Decreasing day length also prompts hibernation in many animals. In all of these examples, photoperiod is controlling organisms’ phenology—the timing of life events, like plant flowering and bird egg laying. Phenology is often tied to the seasons, because of organisms’ responses to day length.

Phenology can also be controlled by other factors, like temperature and the amount of rainfall. As the days grow warmer because of climate change, the timing of organisms’ life cycles is shifting. Spring happens earlier than it used to, and many springtime life events are happening earlier too. In major 2003 study of nearly 700 species, including birds, insects, frogs, flowering plants, and trees, 62% of species’ life cycles had shifted over an average of 45 years. Birds and frogs bred earlier, migrating birds and butterflies arrived sooner, and plants flowered and buds burst earlier.

This is likely leading to a widespread phenological mismatch; while some organisms are responding to earlier springtime temperatures, other organisms are still tracking day length. This means that insects emerge ready to feed on particular plants, but the plants are not yet edible. The insects don’t get their food, and the plants don’t get pollinated. Or migrating birds arrive hungry, and their food source has not yet ripened.

It is difficult to know to what extent phonological mismatches are taking place. A proper study of phenology requires a lot of data—many widespread observations of when a particular plant is flowering, or when and where a particular migratory bird is present. This is where you come in. The National Phenology Network has a citizen science program that allows people across the country to record their observations of plants and animals. This crowd-sourced data will be used to determine the extent and effects of shifts in the timing of organisms’ life cycles.

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Extreme ultraviolet composite solar image from NASA's SDO.
Credit: NASA/SDO

"If that was a scoop of ice cream, what kind would it be?" I asked the 7-year-old girl visiting our 20-inch telescope's dome.

A pensive look crosses her face, as if she were standing at the counter of an ice cream parlor looking at the list of flavors. "Mint chocolate chip," she decides.

The girl was looking at a new video display recently installed in the observatory at Chabot Space & Science Center, which shows up-to-the hour, time-compressed movies made from the spectacular solar imagery coming out of NASA's Solar Dynamics Observatory (SDO).

And it really does resemble a big, luminous, writhing ball of colorful ice cream (though what "writhing ice cream" is, I'm not certain; use your imagination).

Kept up-to-date by an Internet feed from Lockheed's Solar and Astrophysics Lab in Palo Alto, the display at Chabot is showing visitors visions of our Sun unlike anything that has preceded it.

SDO was launched last year, and since then has been capturing high resolution, multi-wavelength visible and extreme-ultraviolet imagery at very frequent intervals. Its array of extreme-ultraviolet imaging telescopes (the "AIA" instrument) captures the energetic UV emissions from the Sun's hot atmosphere, revealing in extraordinary detail the Sun's busy and complicated magnetic activity: hot active regions, solar flares, coronal mass ejections, magnetic loops and arcs, and prominences.

The various images taken at the different wavelengths are blended together into an exquisitely colorful, nuanced, and delicious movie of a day of the life of the Sun (and with about 24 hours of images compressed into a few seconds, you really can see a day of its life!).

SDO was built to give us a much more detailed picture of what makes the Sun tick as we enter the 24th Solar Cycle, which started in the last few years. A Solar Cycle is the period over which solar magnetic activity rises, climaxes, and falls again. Solar Cycle 1 started around the year 1755, and in the intervening centuries we've been through 23 cycles, which have averaged pretty reliably at about 11 years long each. (Solar Cycle 1, by the way, wasn't the first; that's just when they started numbering them, shortly after their discovery.)

Over the past few years, the Sun has been pretty quiet; our solar telescopes at Chabot have seen few sunspots (markers of regions of magnetic activity), and even the Sun's energetic atmosphere has been more or less quiescent, with only the occasional prominence or filament ("clouds" of cooler gases confined by solar magnetic fields) visible through special "Hydrogen-Alpha" filters.

But that's all changing now. Through our visible light telescopes, beautiful groups of sunspots have started making regular appearances, crossing the Sun's face as the Sun slowly rotates in space. Sunspots appear darker than the surrounding visible surface of the Sun, being a couple of thousand degrees cooler—but they are still quite bright; if we blocked off all of the Sun's light except that shining from an average sized sunspot (average meaning Earth-sized), it would appear as bright as the Full Moon on a clear night.

Through our Hydrogen-Alpha telescopes, prominences and filaments are becoming far more numerous, and more amazingly huge than over the past few years of minimal solar activity.

And the SDO movie display is revealing to us a great deal of activity—hot spots of magnetic mayhem spouting from within the Sun and surging into the atmosphere. With the peak of solar activity of Solar Cycle 24 expected to occur sometime in 2013, we're in for at least a couple of years of ever-increasing fireworks on the Sun, with all the related space weather storms, auroral light shows, and cell phone interference that comes with it.

What flavors of Sun are we serving then? Well, we have vanilla of course, served up by our little Sunspotter visible light telescopes—vanilla is my favorite ice cream…. And the Hydrogen-Alpha scopes scoop burgundy cherry and bubblegum in nice spoon-sized portions (bubblegum not your taste? Try some of ours…).

Imagery from the old and reliable SOHO satellite solar observatory offer blueberry, key lime, butter brickle, and strawberry. And the new SDO movies provide our newest menu items: mint chocolate chip, pistachio and black cherry, rainbow sherbet, and blueberry walnut banana supreme…or whatever unusual and mindboggling combination that comes to your mind when you look at them!

Come on up to Chabot for a taste! Napkins not provided….

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The Sun in the act of crossing the horizon.

The inquirer wanted a scientific response—that he was a history major, and was having some difficulty trying to debunk the rumor with someone he knew.

I explained that, no, I knew of no evidence to support the claim. To the contrary, Earth's North Pole was still pointing less than a degree away from the trusty North Star, Polaris, as it had been, more or less, for hundreds of years, still serving as the same constant marker of north today as it had been for seafaring navigators long ago. Had Earth's axis shifted by three degrees—in any direction—Polaris would consequently have moved far enough of the mark of the Celestial Pole for all to see—those who cared to look closely, at any rate. Certainly not something that a cover-up could keep secret. Seasonal conditions, too, would be affected, for all to experience.

I was thanked, and told that the explanation might be enough to assuage the concerns of the writer's acquaintance.

The next day I got an email from the acquaintance—actually, brother—a man in Missouri. I was told firmly—though politely—that I must be wrong, for he had seen the evidence with his own eyes: after a lifetime of knowing the Sun rises precisely in the east, one morning not long ago, he suddenly observed the Sun to rise quite a distance to the north of east.

I took the time to ask for a more detailed description of what the man had observed, and continued my explanation by talking about the seasonal change of the Sun's rising position caused by its annual trek northward and southward in the sky along the tilted plane of its path, the ecliptic.

The next email I got had a MapQuest map attached, with markers added. This man was certainly doing his homework.

"The red star marker is my driveway; the white hand symbol is the nearby mountain where I saw the Sun rise. This is simply not possible unless there has been a major change in the Earth's position."

I pulled out my protractor and slapped it to my computer screen, then wrote back, "Looks like you observed the Sun to rise about 30 degrees to the north of east—which is about where it should rise around summer solstice, from your latitude," (just shy of 37 degrees north).

I went on to say that next September 22nd—autumnal equinox—he should observe the Sun to rise exactly at the east point on the horizon, and on December 21st—winter solstice—it should rise a full 30 degrees to the south of east.

After a couple more emails, my inquisitor's tack had come about somewhat, and he seemed as close as a native Missourian can be to admitting he might have been mistaken without actually seeing the crucial evidence for himself, yet (my father is a native Missourian, so I have some insight here; that's probably where I get it, too). He did say that he would check out where the Sun would rise in September, and decide then who was right–but he conceded that my explanation might turn out to be right.

What impressed me was the man's willingness to keep an open mind despite his apparent concrete convictions, and the earnest effort he made to test the explanation I had provided. I've been there, too: absolutely convinced that this or that was most certainly thus, having seen it for myself, only to find out that it wasn't my observation that was the problem, but my interpretation of what I observed, and perhaps the context I had placed it in.

But if science is nothing else, I feel, it is the frame of mind to question one's own interpretations of reality, and to poke and prod the perception to test what may be fact, and what may be misinterpretation.

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Astrophysicists who track space weather today are at a stage Earth weather forecasters were roughly three decades ago. This is about to change.

I was also surprised to learn how the Sun drives terrestrial weather, the kind that has us grabbing our sunglasses or an umbrella before leaving the house. While producing this story, I interviewed David Dempsey, a Professor of Meteorology at San Francisco University, who illuminated for me the role the Sun plays in this process. According to him, "we wouldn’t have anything we would call weather without the Sun. It shines directly on the lower latitudes of the Earth and less directly at the high latitudes, and that creates a big difference in temperature between the tropics and the polar regions. That difference in temperature in turn creates differences in pressure within the atmosphere that then drives winds. Wherever the air is, it goes up, it cools and you can get condensation of water vapor in the air and clouds form. Clouds then produce rain and they also reflect sunlight back to space, which then modifies the heating of the sun and you have a very complex system taking place across the globe we call weather."

Although weather forecasting has been the subject of much derision, huge strides have been made in weather forecasting, driven by a steady technological progress that has revolutionized the science of meteorology. As Professor Dempsey told me, "we’re probably in the 5 to 7 or even 8-day range as far as making forecasts that have some value to them. Forty years ago, it would have been just a couple of days. Improvements in satellites, in ground-based observations, have all contributed to our better understanding of the state of the atmosphere at any one moment." Take for example COSMIC, six satellites which launched in 2006 and which ingeniously use GPS signals from other satellites to discern the temperature and moisture content of the atmosphere over oceans, which traditional weather balloons, launched from land, can't provide.

Astrophysicists who track space weather today are at a stage Earth weather forecasters were roughly three decades ago when increased computing capabilities allowed them to amass more atmospheric data and analyze the data faster and more accurately. Moreover, with a powerful new tool within their toolkit in the form of NASA's Solar Dynamics Observatory, a satellite that provides a constant, ultra-high resolution view of the sun, the space weather trackers should be able to make more reliable and more detailed forecasts. Phil Scherrer, one of the Principal Investigators on the SDO mission, told me that a reasonable target to aim for is a space weather forecast that would be accurate for roughly a week, which is about what you can expect for a fairly accurate terrestrial weather forecast today.

Today, the stakes couldn't be higher for increased vigilance as our satellites arc through the atmosphere, which for all their state-of-the art ruggedized construction, are still vulnerable to the radiative slings and blows volleying from the Sun. As Professor Dempsey put it, "Solar storms can interfere with our ability to get the data we need, the observations we need, from weather satellites.That can be really critical if you have a hurricane developing off the coast of Florida and you need to know in advance whether you’re going to have all the data you need to try to make your best forecast of the impact of that hurricane. And if you know that you’re going to have an interruption in observations from satellites because of variations in solar output, then you can try to compensate and warn people about it."

Watch the Journey Into The Sun television story online.

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Live solar observing at Chabot Space & Science Center

Our weekend daytime observatory volunteer team has assembled their own live solar observatory, using a SolarMax 70 hydrogen-alpha filter telescope, a video camera, a wireless transmitter, and a large flat-panel display screen—and now that the weather is beginning to cooperate, their offering to our visitors will take place on a more regular basis.

I was up there last Sunday to see the system at work, and was very impressed. With the telescope and wireless transmitter set up outside on the observatory deck, the image of the Sun captured by the video camera was transmitted into the dome of our large telescope, Rachel, where a receiver caught the signal and piped it into the large display monitor attached to the central pier.

Even though there were no sunspots that day—and sunspots are what people generally expect to see, if anything—the Sun put on quite a show in the "hydrogen alpha" wavelength of light (a select red color emitted by hot hydrogen in the Sun's atmosphere). While the Sun's visible surface is populated by features like granules (convection cells), sunspots, and faculae, the h-alpha scope revealed a layer of the Sun's atmosphere, the chromosphere ("sphere of color", named for the bright red light emitted by the hydrogen gas).

We observed several filaments and two or three prominences on this day, even though the Sun was relatively quiet and showing little surface sunspot activity.

Filaments and prominences are the same thing, really: "clouds" of hydrogen gas in the Sun's chromosphere, shaped and contained by the force of solar magnetic fields. When seen at the edge of the Sun's disk, these clouds appear as bright flame-like structures against the dark background of space, and we call them prominences. When seen within the Sun's disk, they appear as dark streaks and strands, the cooler gases in the clouds silhouetted against the brighter surface of the Sun; in this case we call them filaments.

Each of the little puffs of prominence we saw—like bonfires surging up from the edge of the Sun—were actually enormous structures, several times the size of the Earth. And we saw them change as well; in only minutes, the structures would shift and form new shapes, reminding us that the Sun is a very active and dynamic object, always on the go.

Solar activity is now on the rise, after a multi-year lull of quiet as we passed through the bottom of the 11-year solar cycle. We are seeing sunspots on more occasions, which are revealing areas of rising magnetic activity. The activity should only increase going forward, and is expected to reach a crescendo ("solar maximum") sometime around 2012 or 2013. Then, as was the case a decade ago when Chabot Space & Science Center opened, we can expect to see a dozen or so sunspots at any given time, and many more filaments and prominences.

I hope you can make it up to Chabot on a sunny weekend afternoon and see what our volunteers are up to. Forget about that sunny beach; come up to Chabot to learn about the object that makes that beach sunny!

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Iron filings reveal the pattern of a magnet's invisible force field.

That gave me a lot to work with—Sun-Earth Day usually does, but the more opportunity to create hands-on experiences for our visitors, the better, and when it comes to curious natural phenomena, magnetism is a fertile subject for all sorts of seemingly magical fun.

So, I turned Chabot's Chemistry/Physics classroom into a public magnetism laboratory, giving visitors a chance to learn, or relearn, some of the basics of magnets, as well as to connect the tabletop experiments to phenomena that take place on enormous scales on the Sun and the Earth.

First was magnetic polarity: playing with a set of magnets, visitors got a feel for the behavior of magnetic poles—N and S—and how opposite poles attract and like poles repel. (It's always fun to feel the pull of attraction between two magnets, but there's something extraordinary about feeling the push of repulsion—your mind just expects to see little bumpers on the magnets, but there's seemingly nothing there!)

The Earth itself is a giant magnet, as most of us know—but what many of the adults found surprising and intriguing is the polarity of Earth's magnetic field. Using small magnetic compasses, we sought out the Earth's magnetic poles: north and south. By taking careful notice of which type of magnetic pole the compass needle ends pointed to, the fact that the magnetic pole of the Earth up near the geographic north pole is a south—or 'S'—magnetic pole was revealed! This is why in physics we are often careful to refer to magnetic poles as 'S' and 'N', not south and north, to avoid confusion.

At another station, visitors made their own compasses by magnetizing an iron nail stuck through a Styrofoam packing peanut and floating it in a bowl of water. Darned if that floating nail didn't stubbornly turn to point in the same direction, no matter what direction we tried to turn it!

Station 3 was about mapping the invisible magnetic force field surrounding various magnets. Human eyes cannot see magnetic fields—but they are there and have an influence. I had constructed magnetic field mapping devices for this purpose: used CD jewel cases, with paper labeling removed, filled with a sprinkling of iron filings. When shaken gently back and forth—as if panning for gold—the iron filings align and connect in gritty little strings and conform to the pattern of the magnetic field. The strong field converging at the two poles of a magnet were boldly evident, but also to be seen were the more tenuous curls of field lines arcing through the space around the magnet.

The patterns formed by the filings were very similar to the patterns seen in images of sunspots we compared them to. On the Sun, it is not iron filings that trace the invisible magnetic fields for us to see, but hot, electrically charged gas, or plasma (mostly hydrogen and helium, but also traces of calcium, iron, and other elements). Electric charges (electrons and ionized atomic nuclei) are strongly affected by magnetic fields when they move through them. Numerous ultraviolet images of the Sun were available on computer screens around the lab for visitors to compare the magnetic patterns and shapes to.

We had more: building an electromagnet from wire, an iron nail, and a battery. This demonstrates how magnetic fields are created by moving electric charge—in the electrically conductive wire of the electromagnet, in the circulation of electrical current inside the Earth's iron core, and in the motions of plasma on the Sun. It's all moving electricity, friend.

We also conducted "Magnetic Yacht Races": pushing, via the repulsion of like poles, a floating, magnetized 'yacht' across a pond of water. The challenge of steering and propelling the yachts led to some interesting yacht designs; certain configurations of packing peanuts and iron nails proved easier to maneuver and accelerate than others.

Happy Sun Earth Day 2010! I wonder what we'll be doing next year….

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