Orion rising in Death Valley - Credit: Ben Burress

What brings this on? Well, the skies of Death Valley, actually, which I just returned from (Death Valley, not its skies!) over the holiday break. My daughter and I went down there, mainly to crawl around the sand dunes and canyons, visit sites of the Gold Rush pioneers who gave the valley its [English] name, and get another good, up-close look at the raw Earth….

…but, as always, at night, when the campfire sparks warmly, I end up looking to the stars, which are extraordinarily bright in the dark desert skies. And I just get to thinking…again….

My touchstone on the vastness of the Universe is the knowledge that all the stars we can see in the night sky, with our unaided eyes, are quite starkly the closest things to us in the Universe—and even from those objects, light, traveling at 186,300 miles per second, takes years, decades, even centuries just to reach us. These "local neighborhood" stars are all within our Milky Way galaxy, and all among the very closest of them.

So, the stars of the night sky are a sort of "front drop"—like a big sheet of paper with stars printed on it, held before us–and the stars and galaxies of the rest of the Universe, beyond this "front drop," are too far away for our eyes to perceive their light (without the help of a telescope).

Trying to put the scale into perspective (trying very hard!), if this "sheet of paper" with stars printed on it, held in front of our collective Earthly "face", was, say, 1000 light years away (6000 trillion miles—which is actually about the greatest distance that our unassisted eyes can detect individual stars, and only stars of the most luminous type at that), this would be analogous in scale to an individual person holding a star-printed sheet of paper about two tenths of an inch before their eyes (yeah, I know, too close to focus on the printed stars…), with the surrounding Bay Area representing "the rest of the Universe."

What? I didn’t hear you…. What I said was, if the entire Bay Area represents the Universe, then the stars we can see with our eyes are found within two tenths of an inch of our eyeballs…. Even the Andromeda Galaxy, the most distant object unaided human eyes can perceive (and which I did spot as a very faint smudge on the dark Death Valley sky!), at a distance of about 2.5 million light years, would be less than 4 feet away from you in your Bay-Area-scaled Universe.

It’s here that my mind boggles, and it becomes doubtful to me that our brains have the capacity to really wrap around the Universal scale. It’s hard enough imagining the distances to the "nearby" local stars, a space in which light spends centuries crossing; trying to see beyond that big sheet of paper, to the 13.7 billion light year extent of space and time…boggle…fail….

So, the next time you find yourself gazing at the stars, remember that those are just the spots flittering around in front of our collective eyeball, no more than an eyelash away….

And if that makes you feel small, cheer up; you live in a Universe that is altogether astonishing and magnificent, and not just a run-of-the-mill Universe of comprehendible size. I feel honored and proud….

Moon today and during the Cretaceous

Although I am a lifelong fan of science, I've also been a lifelong fan of science fiction—so I sometimes experience conflict in the DMZ where the two meet.

Having been raised on Star Trek, where the science and technology routinely violate known scientific principles (faster than light warp drive, for example), I learned to have leniency on some of those violations—at least, the ones that exist in order to make the story work.

But the stories that get the science completely wrong, for no good reason, get my militia up in arms….

Such was my reaction when, a few weeks ago, I happened upon the last two minutes of the series premiere of a new television show—the one that involves time-traveling colonists going 85 million years into the past to live among the dinosaurs. (Don’t ask me any more about the plot; I’ve only ever caught the last two minutes of each show when I change the channel to wait for House. All I know is each episode seems to end with people creeping through a jungle at night carrying torches….)

So what irked me so badly? Scene: colonists in settlement in Cretaceous jungle, night time, looking up at the starry, Moon-adorned sky. A child muses, "Is that the Moon?" (never having seen it before). "It’s so big!" Indeed, the Moon aloft in these prehistoric skies was depicted as truly huge—I’d estimate ten or fifteen degrees across, about the width of your hand spread wide at arm’s length (20 to 30 times the size of the Moon we know).

Enter "brainy" teenage girl to explain: The Moon is moving away from the Earth a few centimeters each year, so here, 85 million years in the past, it’s much closer to Earth.

How much closer was the Moon to Earth 85 million years ago? Do the math, brain: The Moon is currently moving away from the Earth at about 3.8 centimeters per year, so 3.8 cm for 85 million years equals 323 million centimeters. Sounds like a lot, right? 323 million of just about anything seems like a lot. 323 million centimeters is 3,230,000 meters, or 3,230 kilometers. Or a little over 2,000 miles—which, coincidentally, is about the diameter of the Moon itself. Since the Moon is presently 240,000 miles from Earth, being 2000 miles closer to us in the past (about 0.8%) would not have made it perceptibly larger—let alone appearing as big as a cantaloupe!

The Moon has been moving away from the Earth since its formation, which took place about four and a half billion years ago. Through tidal interactions with the Earth, the Moon has "stolen" some of Earth’s rotational momentum (spin) to gradually boost itself farther and farther away, slowing the Earth’s spin as a result. Back in the day when the Earth and Moon were young and fresh—and much closer together—the Earth spun much faster: maybe once in 8 hours. (But that was WAY before life existed, so try not to imagine the dinosaurs experiencing much shorter days, please.)

Oh yeah, in that same two minutes of the show premiere, the "brainy" girl (it’s not her fault; it’s the show’s writers, of course) also had an answer for why all the stars in the Cretaceous sky bore no resemblance to the constellations we know today. The Universe is expanding, she said (correctly), and so in 85 million years that expansion has caused the stars to change position" (not so correctly). The Universe is expanding, yes, correct; the stars in Earth’s skies 85 million years ago would have looked completely different, yes. But the two have nothing to do with each other.

The Universe is expanding and carrying all of the galaxies and galaxy clusters farther and farther apart. But this has no effect on the stars gravitationally bound within each galaxy. At the scale of a single galaxy, like our own Milky Way, the gravity binding the stars together in that great spinning spiral overpowers the effect of space expanding.

The stars we see in our skies are all inside of our galaxy, to which they are gravitationally bound. It is merely the motion of those stars within the galaxy as they orbit the center that change their relative positions, and so the patterns of constellations that we perceive. Analogously, continental drift on Earth may move a pair of land masses away from each other, but that large-scale motion won’t cause the trees within either of those lands to move apart.

Nit picking? Yeah, maybe. But I even do it to Star Trek on occasion….

NASA's Stratospheric Observatory for Infrared Astronomy, also known as SOFIA. (Photo: NASA)

The new SOFIA observatory isn't your average NASA project. Engineers took a 30-year old 747 airplane, cut a hole in the side and installed a 17-ton telescope. Most telescopes are either on the ground or somewhere in orbit, but SOFIA falls somewhere in the middle, flying around at about 40,000 feet.

I got the chance to hitch a ride on one of its recent research flights as the plane left Moffett Field at the NASA Ames Research Center. It's definitely not the kind of flight where you get a bag of peanuts and movie.

The researchers take advantage of the nighttime sky, so we left at dusk for 10-hour tour flying zigzags across the Pacific Ocean. Each leg of the journey is carefully calculated so the telescope can pinpoint a far away star. The plane interior is packed with computers and equipment. It also lacks insulation since much of it was removed to install the telescope, so it's both cold and loud inside.

At four in the morning, the astronomers are still hard at work. If they're as tired as I am, they certainly aren't showing it.

"For me, this is very exciting," says Ian McLean, a professor at the University of California-Los Angeles. He usually works on the ground. "All my career has been ground-based astronomy. So, it's only my second flight."

McLean says there's a good reason to do astronomy in the stratosphere. The atmosphere is thinner, which means it's easier for the telescope to see the stars. "It's almost as good as space," says McLean. "Not quite, but almost."

And unlike the Hubble Space Telescope, this telescope lands everyday, which means the scientists can update and fix the equipment. "By the time you get a mission into orbit, the technology you're using is relatively old. Here we can stay state of the art all the time," says McLean. NASA began developing SOFIA in 1997 and almost cancelled the project at one point. It flew its first science mission in November 2010 and now costs about $80 million a year to operate.

Searching for a "Holy Grail"

McLean says the SOFIA telescope could show astronomers something that's considered a Holy Grail in their field: seeing a star being born. It happens in huge, dusty clouds – stellar nurseries, as Mclean calls them. "The cloud is huge, light years across and it's gradually contracting to form a whole nursery of stars."

Inside NASA's SOFIA Observatory, somewhere over the Pacific Ocean.

But there's a problem. Astronomers can't see what's happening inside the clouds because, once again, they're made of dust and it's hard to see through.

"We don't mean dust bunnies, but we mean little, tiny little grains of solid material. Doesn't matter how big a telescope you have, you can't see inside it," McLean says.

That's why SOFIA looks at a special kind of light called infrared light. If you look through a telescope on the ground, you're looking at the visible light from space – the light our eyes can see. Infrared light is invisible to us, but it penetrates space dust, which means the telescope can see through the dust too.

"You get to see what you can't see with your eye. It's like a window has been opened," says McLean. They're looking for exactly how stellar nurseries give birth to young stars. McLean says catching a star as it's forming can reveal clues about how own solar system formed.

But star birth isn't the only thing these researchers want to see. They're also looking at the way stars die.

A Star on the Way Out

As the plane makes as sharp right turn, the telescope focuses on an object called NGC 7027. It's a planetary nebula – also known as a dying star. Mclean and his team are capturing an infrared image of the nebula, which is about 3,000 light years away. They can also see what it's made of.

"It has a distinctive shape. It's oval. There's a hole in the middle and that's because it literally is a shell of gas that came off the star," says McLean.

7027 is dying because the star has run out of fuel – the same fate that our sun will face in about five billion years. As it dies, the star casts off its outer layers, shedding huge amounts of material to form a cloud around it. But it's not entirely a sad story.

"It won't be wasted," says McLean. "The material that was thrown off by that star in its dying phase, somewhere, millions, perhaps billions of years from now, will find its way into a new star and the planets that form around it."

From dead stars come new stars – and planets like our own. The oxygen and nitrogen in our bodies were once formed inside a star. "The cosmos is within us," as astronomer Carl Sagan once said. "We're made of star stuff."

As sky begins to lighten, we descend towards the Dryden Aircraft Operations Facility in the Mojave Desert, where the plane is based. The SOFIA telescope is now flying twice a week. Astronomers from around the world are lining up to get onboard.

“Pleasanton Circular File ” by Steven Christenson

Back in the early days of QUEST, when we were first piloting the Your Photos on QUEST segments, Steven Christenson was one of the first photographers to respond to our call for submissions, posting on the QUEST YPOQ Flickr page his set of photos from Mission Peak Preserve near Fremont, California.

When I was trolling for our first YPOQ photographer for the new season of QUEST TV, I went back to some of those early submissions and was immediately struck by Christenson’s set of vibrant, kinetic images, especially his night sky photographs and star circles. Not only are they totally unique and beautiful, there’s obviously a good story to be told in how he actually makes them.

Shooting photographs in very low light is a special skill, one that Christenson has honed to a fine art over the last few years. In fact, he’s gotten so good at it, he was honored as one of the winners of the International Astronomy Photographer of the Year, 2010 awards in the “People and Space” category. Here’s his winning photo, taken at Pfeiffer Beach in Big Sur, California. He shot it as people gathered on the beach during one of the few days each year when the setting sun shines directly through the archway of a large rock formation.

“Photon Worshipers” by Steven Christenson

“Bristlecone Pine Star Circle ” by Steven Christenson

Indeed the process of “finding light in the darkness”, as Christenson puts it, is more involved than one might imagine. First off, you have to get to a place that has a good vantage point on the stars. In Christenson’s case, this usually involves driving and/ or hiking a good distance before he even sets down the tripod. Then, you have to deal with the notoriously foggy/ rainy/ cold Bay Area weather. He’s been battling with the weather at Pigeon Point Light House State Historic Park in Pescadero for years. But he’s managed to get some spectacular images there nonetheless.

Once all the stars align so to speak, and Christenson has set up his shot, the waiting begins. As the earth rotates and orbits the sun, the stars appear to travel through the sky and his camera is set to take an image at set intervals. It can take all night for him to get the images he needs to stitch together his final images. He often sleeps in his car or out under the open sky if weather permits.

For our shoot with Christenson, he took us hiking up Mission Peak, his favorite location in the Bay Area to shoot. Between our audio tech, Helen, associate producer Josh and myself, we’ve collectively lived in the Bay Area for more than half a century and none of us had ever been to Mission Peak. It’s absolutely spectacular up there. It’s one of the things I love most about this job that I have the opportunity to see and experience things that have been under my nose for years but have never noticed.

And if you’d like to join Steven Christenson for a nighttime photography tour of Mission Peak or several other Bay Area locations, be sure to check out the Star Circle Academy website.

QUEST on KQED Public Media.

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Artist's rendering of exoplanets around a star. (Credit: NASA)

The Earth may not be as unique as we think it is. That's according to findings announced today by UC Berkeley. Astronomers there believe that Earth-sized planets may be more abundant in the universe than previously thought.

For five years, a team of scientists lead by UC Berkeley watched 166 stars, similar in size to our Sun and all within 80 light years of Earth. In all, they discovered extra-solar planets or "exoplanets" orbiting 22 of the stars. Some are as large as Jupiter while others are about three times the size of Earth, the smallest planet they can detect. Smaller planets were found more frequently than the larger planets.

"We found smaller planets in spades," said astronomer Andrew Howard of UC Berkeley. Using the data, Howard and his team created a statistical model to predict what other planets might be present. "We extrapolated that trend down to Earth-sized planets."

Howard says the data shows that nearly one in four stars like our Sun could have Earth-sized planets. "This is really the first quantitative estimate of the fraction of sun-like stars that have Earth-like planets. Before, the guesses were all over the map. Some people thought it was 100%. Some people thought it was one in a million."

The 33 planets found in the study orbit very close to their stars, meaning temperatures there are most likely too high to support life. The discoveries were made with the Keck Observatory in Hawaii using 10-meter ground telescopes. The planets were found using the "wobble" of the stars – the subtle movement that occurs when a star is pulled by the gravity of its orbiting planets.

The announcement joins a number of exoplanet discoveries in recent months, including NASA's finding of two exoplanets in August. Today's findings were published in the journal Science.

Howard says while the ultimate goal is to find Earth-like planets that could have liquid water, this finding is an important first step. "People have wondered for millennia: is the Earth common or is it rare? And we're starting to learn that the Earth is not a one-off in the universe. It may have cousins out there."

For more on how scientists find exoplanets, check out this QUEST story.

QUEST on KQED Public Media.

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The Thirty Meter Telescope would be built in Hawaii, atop Mauna Kea at around 13,000 feet. Artist's interpretation courtesy of TMT Observatory Corporation.

Originally reported for KQEDnews.org.

Scientists from the University of California are working with a team of international researchers on one of the most high-profile science projects of this decade: an effort to construct the largest optical telescope on Earth.

The $986 million project is planned for the summit of Mauna Kea, on Hawaii’s Big Island, and will feature a primary mirror 98-feet in diameter.

Scientists working on the project hope to begin construction next year and complete it by 2018 or 2019. They say the facility, dubbed the Thirty Meter Telescope, will allow astronomers to observe with much more clarity some of the earliest stars and galaxies of the universe and investigate what they’re made of.

“We’ll be able to look back at the baby pictures of the universe and trace how it developed,” said Michael Bolte, director of the University of California Observatories and a member of the board of directors for the new telescope.

The telescope won approval last month from the University of Hawaii Board of Regents, which holds the lease to the site.

In addition to exploring the farthest reaches of the universe, the telescope also will be able to routinely and easily produce images of the more than 450 planets that have been discovered orbiting stars outside of our solar system.

Today, the existence of these so-called “exoplanets” can only be inferred by measuring the gravitational tugging forces exerted by the stars they orbit. The telescope also could help determine if some of them have atmospheres similar to Earth’s – the precursor to finding life on another planet.

“It will be one of the most important scientific facilities of the 21st century,” said Bolte, who is also a professor of astronomy at UC-Santa Cruz. “When we look back, it’s going to be the Large Hadron Collider and the Thirty Meter Telescope and I’m not sure what else.”

The project is a joint effort of the University of California, the California Institute of Technology and the Association of Canadian Universities for Research in Astronomy.

A sizable amount of its funding is coming from the Bay Area. The Betty and Gordon Moore Foundation, in Palo Alto, has pledged $200 million toward the telescope’s construction. The University of California and Caltech each plan to raise $50 million. And contributions are expected from the Canadian universities, as well as the governments of China, India and Japan. But 10 to 20 percent of the telescope’s budget still remains to be raised, said Bolte.

The new telescope’s 98-foot (30 meter) mirror would be three times as big as the mirrors on the twin Keck telescopes in Hawaii, currently the biggest in the world, and also owned by the University of California and Caltech. The telescope would produce images three times as sharp as the 33-foot Keck telescopes on Mauna Kea, and would be able to look at objects that are nine times fainter. This would make it possible for scientists to better understand the origins of the universe.

“The universe is 13.7 billion years old and we can see objects that are 13 billion years away, but all we get is fuzzy blobs,” said UC-Santa Cruz astronomer Garth Illingworth, chair of the telescope’s Science Advisory Committee. “We’d like to learn more about these stars and galaxies.”

In January of 2010, Illingworth and his team announced that they had observed the most distant galaxies ever seen. Looking back in time 13 billion years, they found galaxies that were just 600 or 700 million years from the Big Bang. Photographs of these galaxies, which appear as several tiny dots, were made by the Hubble Space Telescope.

Space-based telescopes like Hubble have an advantage over ground telescopes because they don’t have to contend with the blurring caused by the Earth’s atmosphere. But they’re more expensive and therefore, smaller. Hubble’s mirror is less than 8 feet in diameter.

Bigger ground-based telescopes can gather more light than small space-based telescopes. So they make objects that once were faint appear brighter. And the additional light gives researchers information on the chemical composition of objects like stars.

When astronomers understand what a star is made out of, they can better establish its age. And this allows them to plot out the history of the universe more accurately. What’s understood now is that the Big Bang was followed by a period of darkness that astronomers call the Dark Ages. But it’s not clear how long that period lasted.

“There’s controversy about the period before which there were no stars,” said Jerry Nelson, UC-Santa Cruz astronomer and project scientist for the telescope. “The idea is to establish bounds on this. The question is when do you get stars forming that burn holes through this opaque stuff?”

In addition to answering questions about the history of the universe, observers say the telescope could also eventually lead to new energy sources based on the nuclear fusion that fuels stars.

“All those points of light are nuclear furnaces,” said bestselling San Francisco author Timothy Ferris, who wrote “Seeing in the Dark” and other books about astronomy and telescopes. “And they have something to teach us.”

The telescope’s mirror will be made out of 492 closely fit individual hexagonal glass mirrors. The Keck telescopes were the first to use these segmented mirrors to get around the problems created by gigantic individual mirrors. The Keck telescopes were so successful, said Illingworth, that UC and Caltech envisioned the Thirty Meter Telescope as a way to scale-up the Keck model.

TMT Fly-Through from Thirty Meter Telescope on Vimeo.

But big ground-based telescopes have their limitations. Though they can give astronomers more light to study, they can’t by virtue of their size alone make objects appear sharper. To reduce the blurring caused by the atmosphere, scientists use a series of techniques called adaptive optics.

“Adaptive optics is like putting glasses on a big telescope,” said Nelson. A telescope with adaptive optics not only sees sharper images of stars, it also sees more stars.

An expensive and technically complicated process, adaptive optics was used on telescopes for the first time to correct distortions on the Keck telescopes. The technique takes advantage of a layer of the atmosphere that starts about 50 miles above the Earth. This layer is made up of sodium atoms brought in by small meteorites that vaporize as they enter the atmosphere.

Scientists point an orange laser toward the sodium layer. The laser excites the sodium atoms, which become like artificial stars, radiating light back toward the telescope. The process allows researchers to correct for atmospheric turbulence, which causes phenomena such as the twinkle that we see around stars.

Other telescopes in the range of the Thirty Meter Telescope are in the works. An 80-foot mirror called the Giant Magellan Telescope is being spearheaded by a group that includes the Carnegie Institution for Science in Pasadena, Harvard University, the universities of Texas and Arizona and the government of Korea. That telescope is scheduled to be completed in 2018. And Europe is working on the aptly named Extremely Large Telescope, which would have a 138-foot mirror.

“They’re strongly complimentary,” said Bolte. “The Giant Magellan and the European telescope will be in the southern hemisphere, in Chile. So we’ll have access to the entire sky.” Having several of these instruments, he said, would make valuable telescope time more readily available to astronomers.

The Thirty Meter Telescope, which would be built at an elevation of about 13,000 feet, has not been without controversy. Environmentalists say its construction would harm the wekiu bug, a native species that lives atop high Hawaiian peaks. Some Native Hawaiians have come out in opposition, saying that the summit of Mauna Kea is sacred and should not have any more construction.

Scientists hope that the Thirty Meter Telescope will provide answers for many current astronomy questions: What is the invisible matter that makes up 25 percent of universe? What is the mysterious energy that is making it expand faster and faster? But Bolte suspects that just as telescopes in the past surprised scientists by revealing that the planets orbit the Sun and that the universe is expanding, the new telescope’s contributions are impossible to fully predict.

“Every time you build a new telescope with significant new capabilities, you usually solve the problems of the day and find new things you didn’t even know were there,” Bolte said. “The Thirty Meter Telescope will be a bigger jump than any other jump we’ve had, so the new discoveries will be all the more unexpected.”

***

TMT Overview from Thirty Meter Telescope on Vimeo.

Check out these QUEST TV and Radio stories about other University of California astronomy projects:

Illuminating the Northern Lights

Exoplanets

SETI: The New Search for ET

The Planet Hunters

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Tycho Brahe observing the 1572 supernova, with astonished
spectators.

Ever seen one of those? I won't say UFO, because that immediately conjures images of flying saucers and big-eyed space aliens, and that's not what I’m going for here. What I mean is, have you ever seen something in the night sky that you have "never seen before," but that you later learned was actually a natural and recurring apparition, like the appearance of Venus as the Evening Star?

This time of year usually stirs up a phone call or email or two involving "first time" sightings of the bright star Sirius, whose brilliant, multi-colored twinkling catches some people's attention at least once in their lives, causing them to gawk and either wonder why they'd never noticed it before, or assume it's a new thing in the sky, some rare and unusual occurrence.

Sirius did the same thing to me when I was in Junior High. I walked outside one night, looked up, and saw this glittering spectral jewel, brighter than I could remember any star I'd seen. This hook, or teaser, inevitably led me into the adventure of star gazing, because I had to find out what that thing was. But this kind of "revelation" can happen to people much later in life– and in hind sight I'm amazed I hadn't noticed it when I was even younger.

For the past few months, Venus has been in the western sky as the Evening Star– so naturally I’ve been getting more calls than usual. A man who I would guess (by his voice) was past middle age called to report the brilliant white light in the western evening sky, and was stunned to find out it was Venus. I could hear the amazement in his voice that he had never before noticed Venus in his life, after I told him that Venus comes and goes, alternately from the evening and morning skies, but comes back regularly.

And finally I've reached the "point" of this blog: how we can go through sometimes decades of our lives without noticing, or fully registering, something of unusual beauty that has more or less been "in plain sight" all along (or periodically, at least).

My feeling is that is must have a little to do with timing, a little to do with prevailing conditions in our lives, and a lot to do with how we focus our attention on the world around us, or above us. One day we might look to the evening sky and see brilliant Venus flashing over the horizon and not see anything unusual; twenty years later we might look at essentially the same scene and all of our attention and wonder is suddenly drawn to that inexplicably bright light.

See what you think. Go outside one evening in March, look to the south and see if you can spot Sirius– it'll be to the left of Orion's Belt, if you can find that. And, if you're reading this anytime before, say, March 20th, look to the west after sunset and look for Venus. Maybe you've seen these objects before, and know exactly what I'm talking about. Or, maybe, you'll experience something for the first time in your life. Worth a try, isn't it?

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Composite image showing centers of urban light emission
Credit: NASAWant a chance to do some "citizen" science, contribute to an international investigation, and have some fun to boot? An opportunity is coming up in March: Globe At Night. All you need is your eyes….

The problem is summed up in two words: light pollution. A good deal of light produced by human civilization–streetlights, porch lights, shopping malls, security lighting, night time work lights, store fronts, parking lot lights, billboards, neon signs, the list is lengthy–shines or reflects upward into the atmosphere, there scattering off of suspended particles, like dust grains, water droplets, ice crystals and the like.

The scattered light shines back down from the sky, and we see it as a dull nocturnal glow, sometime faint, and sometimes quite pronounced. The amount of scattering particles in the air has an effect on the brightness of the night sky, but the root of the matter is the amount of light sources whose light escapes upward. The closer you are to the heart of an urban area, the more light pollution you will be subjected to.

So what? What's so harmful about that sky glow? Sometimes it can even look kind of pretty….

Well, the fact is, if you've never seen a clear night sky far from sources of major light pollution, you may not appreciate what you're missing: the sight of a clear and dark night sky in which you can literally see thousands of stars. And if you have seen a pristinely dark night sky before, think about the fact that, in 2008, half the population of the Earth was living in cities, many of whom may never have been out of their urban worlds, and for whom the night sky is naturally a dull version of day with a handful of washed out stars above.

There are also effects of light pollution on wildlife that include disturbance of day/night sleep cycles, less cover of darkness from predators, and even effects on plant life.

Globe At Night is a program that's been going on for a few years now whose aim is to measure and monitor the varying levels of light pollution around the world by using individual people as the instruments of measurement.

And it's pretty simple to participate in. The idea is that the brighter the light pollution is in any given location, the few stars you can see. The faintest stars quickly become drowned out in the sky glow, leaving only the brighter ones for your eyes to pick out. All you have to do is go outside on one or more nights in the last half of March, find the constellation Orion (which is pretty easy to find, even in a city), and count the number of stars you see there. Then, report your count through the Globe At Night website, where you'll also be able to see the observations of everyone else around the world, as well as find full instructions for participating.

Now, calendars marked? Know where Orion is? Have a sweater handy? You're all set….

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Depiction of Galileo demonstrating his astronomical telescope.

(Almost as famous as this act of opening our eyes to wonders we'd never witnessed, Galileo was tried by the Inquisition for pointing out that there were more things in heaven than were imagined by Church doctrine–but that's another story altogether…)

It's an intriguing fact that, beyond the Sun merely being a bright disk, the Moon a not-so-bright and slightly mottled disk, the stars pinpoints of light and the planets pinpoints of light that move, everything we have learned about the universe and the objects in it we have learned in the last four centuries, since the invention of the telescope and Galileo's putting it to it's most famous use: astronomy.

Galileo saw on the Moon craters, mountains, and valleys, and likened the "uneven, rough… depressions and bulges" to Earth's geographical features. Venus was revealed to undergo lunar-like phases, which provided controversial insight into the layout of the Solar System. Jupiter had four small "star-like" moons that moved around it–which defied Church doctrine holding that everything in the universe goes around the Earth. And Saturn possessed jug-handle-like protrusions, whatever those were!

It may be difficult to imagine what Galileo was feeling when he made these discoveries of things we take for granted. How exciting to peer through that celestial peephole and discover that the Moon is another world, and that there are worlds out there that had never been seen or imagined before. Sure, new discoveries about Mars keep rolling in, and we're finding a new extrasolar planet about every month–but the excitement about these discoveries is tempered by the fact that we already suspected things like these as possibilities. For Galileo, the magnified astronomical sky was practically a blank canvass.

Back to IYA 2009–what's going on? Who's promoting this, and what is being done to celebrate?

NASA is promoting it, and many different organizations (including Chabot and the Eastbay Astronomical Society) are participating in a number of ways: star parties, special programs, special events, and good old fashioned put-your-eye-to-this-telescope-and-gawk public observing activities.
Honestly, there's nothing like looking through a telescope–and it doesn't have to be a large one. I don't doubt that I first became inspired into astronomy when, as a child, my family would take me to Chabot Observatory to look through the telescopes.

When the new Chabot Space & Science Center reopened the telescopes after the move to our present site, I found all of the childhood wonder flooded back when I put my eye to the eyepiece to regard Saturn. There's an excitement that simply can't be achieved by looking at photographs. You just have to experience it for yourself, as Galileo did four centuries ago…

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Are there more actually more stars in the sky, than there are
grains of sand on all the world's beaches?

Sitting on Limantour Beach at Point Reyes awhile back, watching the waves slosh in and out, listening to gulls and feeling very lazy, I found myself looking about me at all that sand, and wondering how it could possibly be true. Reaching out, scooping up a mere handful of grains and letting–what?–a few hundred thousand of the would-be star proxies fall through my fingers, the notion seemed even more absurd.

Raising my eyes from the bit of the cosmos cupped in my hand and taking in the comparatively vast reaches of sand about me–a hundred or so feet between me and the waves, at least a mile or two of beach visible to the north, another stretch to the south, and who knows how many feet of depth beneath the surface? I simply couldn’t believe it. So, I pulled out my journal and started to write down some figures, working out the problem rationally.

So, is it true? Well, here's what I came up with:

Stars: Astronomers have estimated that there are about 200 billion stars in the Milky Way Galaxy. Galaxies come in many sizes, both much larger and considerably smaller than our home galaxy. I don't know what the average number of stars in each galaxy is, but for the sake of this calculation I chose a conservative 10 billion stars per galaxy. Astronomers have also estimated that there are between 50 billion and 100 billion galaxies in the Universe, based on observations made by the Hubble Space Telescope. Again being conservative, I chose the lower figure of 50 billion. So, with those numbers, I calculate a number of stars in the Universe at 10 billion times 50 billion, or 500 billion billion—or in exponential notation, 5 X 10²⁰.

So how does the number of sand grains in the entire world's beaches stack up against that?

To get to that number, I had to do some estimation. First, pulling some numbers out of the air, I decided that an average sandy beach is 30 meters wide (about 100 feet), and 10 meters deep (about 33 feet). Some beaches are wider, some much less so. I don't imagine that the sand on the average beach is as deep as 10 meters—but I've never taken a shovel and found out, either.

Next, I assume that the average sand grain is a millimeter across, giving it a volume of about a cubic millimeter. With that number, I figure the sand grain density to be 1000³, or one billion, sand grains per cubic meter of beach.

The final piece of the equation–after density, width, and depth–is length: the total length of beach shorelines in the entire world. Here's where I made some serious assumptions. Starting with the total length of shorelines of all continents and islands in the world, I got a figure of 356,000 kilometers from the CIA World Factbook. That's 356 million meters.

Now here's where my estimate becomes truly conservative. In my final calculation, I assumed that all 356 million meters of world coastline consisted of sandy beaches– which is not the case, of course; there are plenty of coastlines that are rocky, pebbly, gravely, ice-covered, or sheer cliffs, all without much, if any, sand.

So what were my results? Well, doing the math, 1 billion grains per cubic meter times a 30 meter beach width times a 10 meter beach depth times a 356 million meter beach length and assuming 100% of the coastlines consist of my hypothetical average beach, I get:

1 billion x 30 x 10 x 356 million x 100% = 1.068 x 10²⁰ grains of sand

Compared to the estimate of stars in the Universe, that's about 5 times as many stars in the Universe as grains of sand in all the beaches in the world! I guess the old adage was not only right, but somewhat of an understatement…

But it's all a thing of scale. I also calculated that there are about 3000 times as many water molecules in a glass of water than there are stars in the Universe…

37.8148 -122.178