Monthly Archives: January 2011

Saturn moon pops its cork

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The crescent moon greeted sky watchers this morning up before sunrise. Credit: John Chumack

Darkness is slipping away at the rate of almost 3 minutes a day as January gives way to the month of candy hearts. That’s how an astronomer might look at the progress of the seasons. The flip side is that the sun is up longer by the same amount. I found a quiet, windless spot on a snowy ridge yesterday, faced the sun and closed my eyes. Seconds later I could feel a gentle warmth on my cheeks and legs. Though the night hours may be dwindling, this daylight thing ain’t so bad.

Ice covers the western end of Lake Superior as far as the eye can this weekend. Photo: Bob King

Even though the sun rises earlier and sets later than a month ago, ice doesn’t form and stick at the western end of Lake Superior in Duluth until mid-winter. It takes weeks of cold days and nights for that to happen. This weekend we had some decent ice on the lake. Nothing you could walk on yet, but it spanned the distance to the Wisconsin shore. The crazed, cracked and bumpy texture of the ice bore a strong resemblance to one of my favorite ice worlds, Saturn’s moon Enceladus.

Enceladus' tiger stripes are shown in false-color blue (at left) in this photo of the moon taken by the Cassini probe. Click to enlarge. Credit: NASA/JPL/ESA

Enceladus (en-CELL-uh-duss) has been in the spotlight in recent years with the discovery by the Cassini probe of water vapor, icy particles and organic compounds venting into space from long fissures nicknamed “tiger stripes”near the south pole. The source of the moon’s many geysers is believed to be an ocean deep beneath the surface. As Enceladus orbits Saturn, it’s alternatively stretched and compressed by the planet’s powerful gravity, generating internal heat that partially melts the moon’s interior. Liquid water is the result.

Geysers of ice particles and organic compounds spew from the tiger stripes or long cracks in the moon's crust. Click to enlarge. Credit: NASA/JPL/SSI

But how does the water manage to find its way through tens of miles of crust to erupt as jets? Last week, Dennis Matson of NASA’s Jet Propulsion Laboratory and colleagues proposed that gases dissolved in the water form bubbles, making it fizzy like a bottle of sparkling water or a soft drink. And if you shake a bottle of soda and then pop off the top, you know what happens.

Bubbles of carbon dioxide that create the fizz in a glass of Coca-Cola

Since the density of bubbly water is less than that of ice, the sparkly stuff rises through the ice and collects in chambers near the surface. When the pressure peaks, the seltzer mix blasts through holes in the surface just like that shaken can of soda. Would that an icy Lake Superior could be so effervescent.

Since we know that Enceladus has salt water (like Earth’s oceans) and organic compounds beneath its crust, it makes you wonder whether it might be suitable for the evolution of life. I’m going to put it on my list of worlds – along with Mars, Europa and Titan – as places where we might find a little company some day.

Of rabbits, rivers and squashed stars

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Not a bad substitute for a star, but I'm up for a change. A snowflake rests briefly on a friend's coat yesterday before tumbling off. Photo: Bob King

Surely the clouds will part and allow a little starlight in. That other variety of stars, the cold, crystalline type, has been falling every day and night the past week. I love snow, but I’m ready for night’s twinkly points of light, even it means suffering the colder weather that often accompanies clear skies in winter.

Just the same, and with optimism ever in my heart, we’ll visit another constellation cluster today. This one centers on Orion the Hunter and includes Lepus the Hare and Eridanus the River. And don’t worry about clouds. These guys will be out from now until the end of February. It’s gotta clear out sometime.

The Orion Nebula is 1350 light years away and about 24 light years across. A cluster of young stars (the bright area) illuminates the nebula. Click to enlarge. Credit: ESO/Igor Chekalin

Orion’s easy to find. Look southeast around 7-7:30 p.m. and midway up in the sky you’ll see the “three stars in a row”. They represent the hunter’s Belt. Below the Belt is a small group of fainter stars called the Sword. The middle one looks mistier than the others – that’s the Orion Nebula, one of the sky’s brightest clouds of dust-ridden gas set aglow by newborn stars within. Binoculars will show a couple bright stars swaddled in a pale white cloud. Telescopes and time-exposure photos reveal just how beautiful and complex this nebula is. Even a small scope shows its pale neon-green color caused by excited oxygen atoms.

If your sky is reasonably dark, try expanding your concept of the Hunter to include his club – a trail of dim stars north of Betelgeuse – and his shield, a wriggly line of suns about one fist held at arm’s length to the right of Betelgeuse.

Bright Orion will help us finder the fainter constellations of Lepus the Hare and Eridanus the River. The hare is less than one fist at arm's length below Rigel, while Eridanus begins only a "finger" or two above Rigel. This map shows the sky around 7-7:30 p.m. in early February. Maps created with Stellarium

Attempting to hide out below Orion but in plain site nonetheless is a rabbit, better known as Lepus (LEE-pus) the Hare. The pattern of the brightest stars reminds me more of a dragonfly, but if you include the fainter ones that represent his ears, the form suddenly looks a lot more rabbit-like.

The name Eridanus (eh-RID-uh-nuss) comes to us from the ancient Greek word for the Po River in northern Italy. The long, sinuous constellation begins above the bright star Rigel in Orion and winds its way just like a real river across a vast wilderness of celestial real estate marked by few bright stars. From mid-northern latitudes, the river appears to end at the horizon.

From the northern half of the U.S. only two-thirds of the winding river Eridanus is visible. To see the rest, we need to head to southern Florida, the Caribbean, South America or Africa. This map shows the sky from Key West in the early evening.

Ah, but it doesn’t, and another clue tells us that there’s more to this constellation than most northerners ever see. You may have noticed in the map above that the river’s Alpha or brightest star is missing. Beta and Gamma Eridani, the second and third brightest stars, are represented, but not the constellation’s crowning glory. To see Eridanus’ brightest star, Achernar (AK-er-nar), you’ll need to fly down to Key West, Florida or points further south. This sounds like a particularly good idea right now.

Artist's conception of Eridanus' brightest star Achernar. Its incredibly high spin rate flattens it into a lentil-like shape. Credit: ESO

Achernar is the ninth brightest star in the sky and a fitting end to our long river journey. Its name derives from the Arabic Al Ahir al Nahr and means “end of the river”. This star is special in another way – it spins at the incredible rate of 155 miles per second. Compare this to our sun’s rotation rate of about once every 27 days! Because stars are not solid balls of matter like planets but composed of pliable gas, when you spin a sun up to Achernar’s demon speed, it flattens out. The river’s Alpha star is one of the flatter ones known with a radius (distance from its center to edge) 50 percent larger at its equator compared to its poles.

I saw Achernar years ago in Aruba, an island off the coast of South America. After weeks of preparation in advance of a total solar eclipse, I finally reached the end of Eridanus while standing on the beach my first night there. It hit me like a surprise ending to a long, twisty tale.

Fresh Swiss cheese from Mars; NanoSail-D photo contest

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Can you see the goofy happy face in this pit on Mars? It's located near planet's south pole in the dry-ice covered "Swiss cheese" terrain, so called because the pits look like holes in the familiar cheese. A typical pit is about 1000 feet across and 25 feet deep. Click to enlarge. Credit: NASA/JPL/ U. of Arizona

Every so often I come across a photo that’s just so otherworldly, I have to share it with all my friends. You’re looking at a pit in the “Swiss cheese” terrain near the south polar cap of Mars released this week by NASA. They call it the Deranged Happy Face. The weird terrain consists of frozen carbon dioxide (dry ice) that sublimates or turns directly from a solid to a gas during the Martian summer and then reforms as the temperature drops in the fall.

A wider view showing lots of pits - cheese holes - near the south pole of Mars. Credit: NASA

The 24-hour sun shining at a low angle during the summer heats the walls more than the floors of the pits, causing them to vaporize and expand and change the pits’ outlines. Take a look at these side by side comparison photos of the Deranged Happy Face taken in June 2007 and December 2010. You’ll see lots of changes in its features caused by cycles of vaporization and recondensation of dry ice.

To this date, no cheddar or Brie have been discovered on the Red Planet, though I remain hopeful that will change as instrumentation improves.

NanoSail-D, NASA’s grand first experiment using solar sail technology, is orbiting 404 miles above the Earth and proving very tricky to spot. Only a few dedicated satellite watchers have succeeded in tracking it. From what I’m hearing, it’s been caught flashing as bright as 2nd magnitude or similar to stars in the Big Dipper. At other times, the sail’s been 7th or 8th magnitude, requiring binoculars to see.

The NanoSail-D team gathered around their sail after a successful laboratory deployment test. Credit: NASA

Although NASA scientists hope to measure the pressure of sunlight on the sail, its primary mission is to determine the degree of drag on the sail caused by the rarefied upper atmosphere.

“Our mission is to circle Earth and investigate the possibility of using solar sails as a tool to de-orbit old satellites and space junk,” explains Dale Alhorn, NanoSail-D principal investigator. “As the sail orbits our planet, it skims the top of our atmosphere and experiences aerodynamic drag. Eventually, this brings it down.”

The hope is that future satellites can be equipped with sails that would pop out like umbrellas. Once deployed, the satellite would return to Earth via aerodynamic drag, burning up harmlessly in the atmosphere. Given all the space junk in orbit, sails might be a good start to getting rid of stuff we no longer use up there.  Read more about the topic HERE.

For the Duluth region, NanoSail-D will fly by for the last time in a couple of weeks tonight starting at 5:30 p.m. Traveling from the west to northeast very low in the sky, it will pass less than a degree below the bright star Vega at 5:32:30 p.m. moving from the left (west) to east (right). For times for your town, login to Heavens Above or click on Spaceweather’s satellite flyby site and enter your zip code.

If you’d like to try your hand at photography and maybe even win a few hundred bucks, NASA and Spaceweather. com have launched a photo contest to see who can shoot the best pictures of NanoSail-D. Anyone can participate. They’re looking for everything from pictures taken by point-and-shoot cameras to carefully guided images made through large telescopes. The photos will be judged on beauty and technical merit; prizes range from $500 for first place to $100 for third. Click HERE to learn more and enter.

Duluth, Minneapolis and aurora from orbit

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Astronaut Jeff Williams from Winter, Wiscsonsin, delivers the keynote address before the Duluth Civil Air Patrol's Annual Awards Banquet Thursday. Photo: Bob King

Last night I was assigned to photograph NASA astronaut Jeff Williams speaking at the Duluth Civil Air Patrol awards banquet here in Duluth. Williams was born in Superior, Wis. just over the bridge from Duluth, but Winter, Wis. is now his hometown.

Williams, who’s logged over 362 days in space, spoke about life on the International Space Station while showing videos of astronauts working on experiments, celebrating Christmas and having fun. Mixed in were dozens of spectacular still photos he’d taken from orbit including the Himalayas, coral reefs (his favorites) and an image I’ve been hoping to see for a long time – the city of Duluth at night. His photo was even better than I’d imagined.

In this orbital view, Minneapolis is at lower left and Duluth and the western end of Lake Superior right of center. The aurora hovers well above the Earth's surface in the distance. Credit: Jeff Williams/NASA

The wide shot includes Minneapolis, Duluth and in the distance, a green arc of aurora following the the curve of the Earth. You can also tell it was taken in winter; the ground is covered in snow as far you can see.

The photo flashed up for only a couple seconds. Not knowing in advance it was coming, I wasn’t in a great spot to get a picture of it, but I grabbed what I could. When the program was over I introduced myself to Jeff, a very intelligent and affable guy, and sheepishly handed him a piece of paper with my e-mail address, hoping he’d find time one day to send me a high-resolution version of his photograph.

During his talk, I was surprised to learn how long it takes to “come back to Earth” in terms of getting your sense of balance back after living in the station’s weightless environment.

Commander Jeff Williams (left) and Flight Engineer T.J. Creamer talk to U.S. service members stationed in Baghdad in December 2009. Credit: NASA TV

Astronauts return from their missions in a Russian Soyuz capsule, landing on the Russian steppes with the help of a parachute. Williams described landing as a rough ordeal “like a train wreck” or “being in a car accident”. The first sensation of gravity is a powerful one.

“It feels like you’re being sucked down by a giant magnet,” he said. Although astronauts soon get accustomed to the Earth’s pull, a full recovery of their sense of balance takes up to two months. You and I can close our eyes and still walk forward or backward because the vestibular system in our inner ears, responsible for our sense of balance and orientation, is adapted to Earth’s gravity. Astronauts who spend a long time in space before returning to Earth would tip over and fall trying to do the same. Until their vestibular system kicks in, they have to rely on visual cues from their environment to stay balanced.

One audience member asked Williams what we’d be doing in space 20 years from now. He thought about it for a few seconds and replied “I honestly don’t know.” He then went on to say that the choices we make for our space program depend on our country’s political will. If the public and our representatives want to send astronauts to the moon or Mars, we can make it happen. Technology is up to the task, but the decision to appropriate the money and stay in the game for the long haul is up to us.

The waning crescent moon joins Venus Saturday and Sunday mornings at dawn. This map shows the sky around 6:30-45 a.m. or about an hour before sunrise. Created with Stellarium

It’s also up to us whether we want to get up tomorrow or Sunday morning to catch the crescent moon swinging by Venus, the brightest of the planets. The pair will be out at dawn and make a beautiful sight in the southeastern sky.

Finally, I should mention that the Jeff Williams’ second home, the International Space Station (ISS), continues to make passes during morning twilight over the U.S. The times listed below are Central Standard and good for the Duluth region. For times for your town, login to Heavens Above or click HERE and type in your zip code. Tomorrow we’ll have an update on what that orbiting solar sail NanoSail-D has been up to.

  • Saturday, Jan. 28 beginning at 5:27 a.m. and again 6:59 a.m. The first is a brief appearance in the east-northeast. The second is a pass across the northern sky
  • Sunday, Jan. 29 at 5:53 a.m. high across the north. Bright!
  • Monday, Jan. 30 at 6:19 a.m. Pass across the northern sky. Bright!
  • Tuesday, Jan. 31 at 6:44 a.m. Pass across the north again.
  • Weds., Feb. 1 at 5:38 a.m. only in the northeastern sky and again at 7:10 a.m. across the north
  • Thurs. Feb. 2 at 6:03 a.m. across the north
  • Friday, Feb. 3 at 6:28 a.m. across the north
  • Saturday, Feb. 4 at 6:54 a.m. high pass in the north. Bright!

What’s outside Leona’s window?

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"Mystery" object outside Leona's window. Maps created with Stellarium

I got an e-mail the other day from an elderly woman named Leona. From her apartment’s west window she watched a “satellite” travel to the north night after night before she went to bed around 9:30-10 o’clock. Sometimes it was bright, other times fainter, and once in a while it jiggled about. Not many satellites are out that late in the winter, and they rarely take the same path every night. Hmm … was it a plane?

“No, I’d know it was a plane, with those blinking lights,” she said. Its northward path could make it a spy or reconnaissance satellite, but it wouldn’t be out the same time every night. Then it hit me. Jupiter! It’s in the west around 9 and creeps northward as it sinks toward the horizon. We were both tickled to figure out the answer.

The familiar asterism of the Great Square of Pegasus is one fist held at arm's length to the upper right of Jupiter. From there, it's an easy ride to Andromeda and Aries. The Andromeda Galaxy is a bit of fuzz to the naked eye from dark skies, but easy to see in binoculars even from the suburbs. The map shows the sky facing southwest around 7 p.m. in late January.

You’ve probably noticed that Jupiter has been drifting to the west over the past month. While still high in the southwest shortly after sunset, it’s already halfway to setting by dinnertime. Earth’s incessant orbital motion around the sun means that we’re leaving Jupiter behind; each night it drifts one degree farther to the west and sets four minutes earlier. As long as the planet’s still easy to find, let’s use it for last looks at three of fall’s best-known constellations: the Great Square of Pegasus, Andromeda the Chained Princess and Aries the Ram.

Place the star Beta off to one side of your binocular view to help you find the Andromeda Galaxy.

Start your observing session around 7 o’clock by facing southwest into the eye of Jupiter. One fist above and to the right of the planet is the most obvious part of Pegasus the Winged Horse – the Great Square. It’s a big, open box bounded on four corners by stars of similar brightness to those in the Big Dipper. The uppermost star actually belongs to Andromeda but is informally considered part of the Square.

Andromeda begins at the top of the Square and looks like a “two-fist” tall carrot with a narrow bottom and wider top. Depending on how dark your sky is, you might be able to spot the Andromeda Galaxy “two fingers” or some 5 degrees to the right of Beta with your naked eye. Look for a softly-glowing fuzzy spot. A pair of binoculars will show the spiral galaxy, located some 2.5 million light years away, with ease. If you look closely, you can distinguish its brighter core called the nuclear bulge, where most of the galaxy’s older stars are concentrated, from the fainter disk, home to its spiral arms and younger stars.

The double star Gamma Arietis photographed through a telescope. Credit: Dr. F. Ringwald/Cal. State Univ. Fresno

Returning to Beta, look a fist to the left of the star to find the small, 3-star figure of Aries. Small telescope owners should definitely check out Gamma Arietis, the faintest of the three. To the naked eye it’s a solitary star, but a small telescope will show two side-by-side, pure white stars like a pair of beaming headlights. Gamma is a double star 204 light years away whose companions orbit about one another with a period of at least 5000 years.

Gamma’s also known as Mesarthim (mess-AHR-tim), and while inconspicuous to the eye, it’s famous as “the first star of Aries”. Back in ancient times, Mesarthim was the star closest to the vernal equinox, the spot the sun occupies on the first day of spring. The Babylonians started their calendar year with the sun at the vernal equinox, making Aries the first “sign” of the zodiac. Because of the slow wobble of the Earth’s axis called precession, that location has since slid westward into Pisces.

Mesarthim was a rock star in its prime. These days it’s successfully made the transition to a second career as double star. This weekend we’ll look at another cluster of constellations centered on Orion.

Be part of history, send your name to Mars

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Hey, baby, my name's going to Mars.

Feel like going to Mars? The good folks at NASA’s Jet Propulsion Laboratory invite you to send your name on a microchip that will fly to the planet later this year aboard the Mars Science Laboratory rover Curiosity. As of 9 a.m. this morning, 1,015,447 people around the world had signed on. Click HERE to fill in the form with your name, country and zip code. You’ll even get a nifty certificate confirming you’re part of an historical mission. Everything’s free. In 10,000 years, when we’re all gone, that microchip will still be there as the Martian dust devils whirl past.

Mars photographed this morning by the space-based Solar and Heliospheric Observatory. Try to visualize the planet as being behind the sun, which is represented by the white circle. Credit: NASA/ESA

Speaking of Mars, has anyone seen this planet recently? Probably not. It’s dogged the sun so closely in the evening sky, the planet’s been lost in its glare for weeks.

Mars and Earth draw near one another about every two years for a period of six months, give or take. The rest of the time, the planet is either too far away from us to make a bright appearance in our skies or too near the sun to easily view.

The reason Mars appears so close to the sun is that it, the Earth and sun lie almost in a straight line. We look in the direction of the sun and beyond it towards Mars. Illustration: Bob King

Mars is in conjunction with the sun next Friday February 4. That’s when it will line up almost directly behind the sun as seen from our viewpoint here on Earth. You can tell from the photo above, it’s closing in. When Mars moves behind the sun, it’s on the opposite side of its orbit from Earth and very far away. 129 million miles will separate our worlds at conjunction next month. Compare that to 35 million miles, when the two planets are lined up on the same side of the sun and as close as they can be. The next favorable lineup of our worlds will occur on March 3, 2012, when Mars will shine almost as brightly as Sirius.

Don’t look for the planet anytime soon. After conjunction, Mars takes its sweet time gliding away from the sun, spending months in morning twilight. By fall, it grows in brightness and becomes more easily visible.

Opportunity Rover is exploring the area near the rim of Santa Maria crater. Sand dunes cover its floor. Credit: NASA/JPL/Caltech

The current Mars rovers, Spirit and Opportunity, celebrated their 7th anniversaries on the Red Planet this month. For the fourth time since they landed, Mars will slide behind the sun at conjunction. To avoid the chance that a command from Earth could be corrupted as it passes through the hot, magnetized gases around the sun, NASA refrains from sending commands to the two orbiting Mars spacecraft and the rovers. A corrupted command could cause the machines to malfunction. The “blackout period” begins tomorrow and lasts until February 11. The rover team has already sent commands to Opportunity in advance, so it can continue working during the moratorium. Opportunity will to transmit any data to the Mars Odyssey satellite, which will relay it back to Earth. Even if signal is corrupted by the sun, no harm can come to the spacecraft.

This recently-released photo shows a large landslide deposit (from left to right) in the in Mars' Ius Chasma region. It was taken by the orbiting Mars Odyssey craft. Credit: NASA/JPL/ASU

Jellyfish, crab and spaghetti are on the menu tonight

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Fireworks at Bayfront Park in Duluth last July 4th. Photo: Bob King

Supernovae are the grandest of nature’s fireworks. Picture yourself watching a typical 4th of July or end of year fireworks display. If you’re observant, you might see the burning fuse as the shell ascends. Moments later, the fuse burns into the shell, igniting the black powder and sending out a shower of multicolored stars that expand into flowers, horsetails, hearts and even the planet Saturn. Each individual firework lasts only seconds before turning to smoke, that’s carried away by the wind.

When stars explode, they leave something similar to fading fireworks in their wakes but lasting tens of thousands of years compared to the brief flashes with which we’re familiar. Called supernova remnants, they’re among the most beautiful and delicate of nature’s creations.

The Crab Nebula, so called because its tendrils reminded an early observer of a crab's legs, was spawned by a supernova in the year 1054 A.D. that became brighter than Venus. Click to enlarge. Credit: NASA/ESA

As discussed yesterday, a star becomes a supernova when one of two things happen: it runs out of burnable nuclear fuel in its core and collapses (Type II), or burns explosively when it’s grabbed more material from a companion star than its core can support (Type Ia). Either way, the star blasts away much of its former self into space at speeds up to 20,000 miles per second or about 10 percent the speed of light. The shock wave and debris from the explosion ram into the surrounding space, colliding with interstellar dust and gas to create an expanding shell of glowing filaments and whorls. Voila! A supernova remnant is born. Some remnants, like the Crab Nebula and the incomparable Veil Nebula in the Northern Cross, are easily visible in small to medium-sized amateur telescopes.

Simeis 147 in Taurus is some three degrees across or six times the size of the full moon. It's also extremely faint. After several tries over the years, I finally succeeded in seeing several filaments earlier this month. Click to enlarge. Credit: Davide De Martin/ESA/ESO/NASA/DSS

As the shock wave ripples across the light years, remnants can blossom into enormous and intricate forms. Simeis 147 in Taurus is 150 light years in diameter and has an estimated age of 40,000 years. That is one long-lasting firework display! Two other remnants are located in the same vicinity, IC 443 in Gemini, nicknamed the Jellyfish Nebula, and M1 in Taurus, better known as the Crab Nebula. I’ve searched high and low for a nickname for Simeis 147 and found none. Based on its uncanny resemblance to a plate of spaghetti, I’ve decided to christen it, yes, the Spaghetti Nebula.

IC 443 in Gemini, a.k.a. the Jellyfish Nebula, is the remnant of a supernova that exploded about 8000 years ago. It's visible in moderate-sized amateur telescopes. Click to enlarge. Credit: Tom Bash and John Fox/Adam Block/ NOAO/AURA/NSF

When a white dwarf burns up in a Type Ia supernova, it may leave a remnant but that’s about it. More surprises await in Type II explosions, when a supergiant star 4 to 8 times larger than the sun explodes. Deep within its core, the supergiant cooks up one element after another, using each as fuel until it burns its way to the element iron. Unfortunately for the star, iron can’t be cooked to create additional elements, so nuclear burning stops. Without the outward pressure of heat to push back against the force of gravity, the star collapses in upon itself, crushing the iron-nickel core into a superdense ball of pure neutrons about 10 miles in diameter. Neutrons are the neutral particles that accompany the protons inside an atom’s nucleus. When the outer layers of the star are blown off, this neutron-packed core, now called a neutron star, shines meekly through the dissipating gases.

Our three featured supernova remnants are all visible in the winter sky within and along the edges of the Milky Way where it passes through Taurus and Gemini. This view shows the sky facing south around 8:30 p.m. Created with Stellarium

The once-mighty supergiant has been reborn as tiny tot that packs the mass of 1 1/2 suns into city-sized sphere of enormous density. A single tablespoon scraped from its surface would weigh 100 million tons! During the collapse, the supergiant’s core spins up to fantastic speeds. A newborn neutron star whirs on its axis many times per second and shoots beams of subatomic particles into space at nearly the speed of light. We see these beams as pulses of light and radiation, hence the name pulsars for rotating, beaming neutron stars. All three of our featured remnants have pulsars buried within their nebulous folds.

Artist's view of a rotating neutron star called a pulsar. The blue lines represent the star's powerful magnetic field; the purples are twin beams of subatomic particles. Credit: NASA

Want a little treat? Check out this video featuring the sound of the Crab Nebula pulsar spinning and beaming 30 times a second. Radio waves from the pulsar have been converted into audio for your listening pleasure.

Fireworks both at home and afar have the same effect on our senses. They make us ooohh and aaahh at the wonder of it all.

New bright supernova flares up in galaxy near the Little Dipper

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If you face southeast around 1 a.m. tomorrow morning, you can watch the moon come up in the company of Saturn and Spica, Virgo's brightest star. Maps created with Stellarium

It seems like it wasn’t all that long ago that to see the planet Saturn, you had to get up just before dawn. Now it rises in the southeastern sky before midnight – 11:15 p.m. to be exact. Tonight it will come up with more than the usual fanfare. Watch around midnight and later when the waning gibbous moon and Spica join the planet in a compact celestial triangle.

Saturn through a 10-inch telescope on Jan. 22. The white band near the top of the planet is an enormous storm that's been raging for over a month. Credit: John Chumack

Saturn’s still too low to get a clear view of its rings until after midnight when it rises above the atmospheric muck. A small telescope magnifying 30x or higher is all you need to see them and the planet’s brightest moon, Titan. Larger telescopes show more than one ring and additional moons. The monster ammonia ice storm/blizzard in Saturn’s cloud tops that began late last year has expanded to approximately the diameter of the planet or some 74,000 miles. That’s over 9 times the diameter of Earth! Look for it in the planet’s northern hemisphere, where it appears as a lighter-toned belt.

You'll need at least a 6-inch telescope and dark skies to spot the galaxy NGC 2655, located near Polaris the North Star. This map shows the sky looking north around 8 o'clock.

I was blown away Saturday night when I aimed my scope at a recently discovered supernova or exploding star in the galaxy NGC 2655 in the dim constellation Camelopardalis the Giraffe. Located not far from Polaris, this spiral galaxy is about 81 million light years from Earth.

Dozens of supernovae are discovered by amateur and professional astronomers each year in both near and remote galaxies. Although we might have to wait hundreds of years for one to show in the Milky Way, the odds of seeing them increase if we expand our sample to hundreds of thousands of galaxies. Numerous supernova search programs are underway, many of which are carried out by amateur astronomers. They select a set of galaxies, photograph them, and then compare the photos to reference photos taken earlier, looking for signs of “new” stars in the galaxies. Followup observations determine if the new star is really a supernova or just an asteroid passing by in the foreground.

Supernova 2011B is located 32 arc seconds east and 22 seconds south of the core of the 10th magnitude galaxy NGC 2655. All the other stars in the picture belong to the Milky Way galaxy. None of NGC 2655's stars are visible - except for the supernova - because the galaxy's great distance makes them too faint. This photo was taken on January 21 by Australian amateur astronomer Joseph Brimacombe

The Japanese comet and supernova hunter Koichi Itagaki discovered the exploding star in NGC 2655 on January 7 when it was still very faint. Many supernovas remain faint and difficult to see in amateur telescopes, but this one was different. Within a week, it became bright enough to see in a 10-inch scope, and now it’s even visible in a 6-inch telescope.

A supernova looks like a star superimposed on a galaxy. 2011B must have been one heck of an explosion, because it’s currently brighter than the entire inner core of the galaxy. That’s what was so amazing Saturday night – seeing and realizing the power of a stellar blast bright enough to outshine the combined light of millions of stars. Wow!

Artist's view of a white dwarf (bottom), surrounded by material pulled off its companion (top). This is how the system looks before the explosion. Credit: ESO

Supernovas come in two basic varieties, Type II and Type Ia. When a supergiant star exhausts its supply of fuel, collapses and then rebounds, blowing itself to bits, that’s a Type II.

Type Ia originate in very close double stars, where one of the companions is a superdense star the size of Earth called a white dwarf. It orbits a normal star like the sun so closely, that the dwarf’s gravity pulls matter from its companion and funnels it down to its surface. When the white dwarf “gains more weight” than its core can support, the star collapses. This heats the core to billions of degrees in a matter of seconds, and the star goes up in a roar of nuclear flame. 2011B is a Type Ia and its brightness attests to a truly cataclysmic event in progress. Well, not in progress right now. It happened 81 million years ago and we’re just getting the news this month!

Artist's view of an exploding white dwarf some 20 days after going supernova. Credit: ESO

I realize some of you reading this may want to give the supernova a try. It won’t be easy if you’re a beginner, but if you know your way around the sky or have a computerized go-to telescope, you’re up to the challenge. To find the galaxy, you can use a printed star atlas or one of the many planetarium software programs such as the free Stellarium in my links column. Another option is the Virtual Telescope online atlas. Scroll up to the telescope part, type in the object’s position (R.A. = 8 55.6, Dec. = 78 13) and click on the Aim Telescope button. That will give you a general view. To get in closer, change the field of view to 10 or 12 degrees and the Deep Sky Object magnitude to 11.  The supernova is a bit southeast of the galaxy’s center and currently magnitude 12.8, well within the range of a 6-inch scope under dark skies. Magnifications of 100x and up will show it as a star tucked into the galaxy’s hazy outer envelope.

Even if you’re unable to view the supernova, it’s fascinating to realize that an exploding star seeds space with many of the heavier elements needed for the formation of planets and life. You’re reading this because generations of stars burned out or blew up to get you here. For more pictures of 2011B and other supernovae, be sure to check out Joseph Brimacombe’s Flickr page. Another excellent resource on current supernovae is Dave Bishop’s Latest Supernovae site.

Invitation from the Milky Way

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Cold both creates and locks in some of the most beautiful ice creations of the season, including this array of icicles along the bank of Amity Creek in Duluth yesterday. Photo: Bob King

I felt the true meaning of cold last night when there wasn’t enough strength in my fingers to turn a thumbscrew while trying to disassemble the telescope. I shook my arms like crazy until a meager bit of warmth returned, and I was able to tease and prod the screw loose. On the way home, the car heat was set to full blast. I steered with my inner arms while my fingers clung to the heating vents for warmth.

Such is the price one pays for standing under a nice, dark winter sky away from city lights. Only when you’re away from the city can you appreciate the subtle glow of the winter Milky Way. It’s really divided into two large sections as seen from mid-northern latitudes. There’s the Cassiopeia half, which stands straight up from the northwestern horizon. On the opposite side of the sky, rising higher as the night goes by, is the Orion half.

At left, is an artist's view of how our galaxy would look from above. The photo at right shows the edge-on view looking at it from the side. The sun's position in both views is marked. When we look straight into the galaxy's starry disk, billions of stars stack up to create the milky band of light we call the Milky Way. When we look up through the disk and into the nearly empty space beyond the galaxy, we see only a scattering of stars, no band. Credit: NASA/JPL/Caltech (left); courtesy Ned Wright (right)

First, a couple of definitions. The Milky Way is the name given both to our galaxy and the milky band of starlight we see at night. We can only ever see part of the 360-degree circular band of the Milky Way galaxy, because it’s cut off by the horizon. And although our galaxy is a magnificent barred spiral some 100,000 light years across, we’re forever stuck in the middle of its flattened disk. We can’t jump in a rocket ship, travel at light speed and hover above the galactic plane to marvel at the Milky Way’s radiant central bulge of ancient stars or truly appreciate the symmetry of its spiral arms dotted with pink clouds of glowing gas. Nope. Located as we are inside the galaxy, when we look through its disk on a dark night, we see stars stacked upon stars stacked upon stars – so many that they blend together into a thick band of soft light tied like a ribbon around the sky.

The Milky Way is the faint band of light running through the center of both photos. The Orion half is fainter and less defined than the Cassiopeia portion. Details: 16mm lens at f/2.8, ISO 3200, 30-second exposure. Photos: Bob King

The Cassiopeia half in the northwestern sky is definitely the brighter, easier portion of the wintertime Milky Way. It shows lots of texture created by numerous star clouds and thick seams of dark, unlit gas called dark nebulae, too. Turning around to look at Orion, I’m reminded of the wispy curls of steam rising from Lake Superior on subzero mornings. The band runs from just left of Sirius (star at bottom in the photo above)  and grazes the east side of Orion before ascending into Gemini and Auriga. The portion from Orion southward is soft, faint and nearly featureless. Even though the starry band narrows in Auriga the Charioteer, it’s a bit brighter and stands out better. Though the band looks like little more than mist, it’s comprised of billions of stars, mostly faint, distant ones. Binoculars and telescopes resolve it into individual stars and clusters, and give us a flavor of its true nature.

The red arrows indicate the direction we look into on summer evenings - toward galactic center. The blue arrows on winter evenings - into the outer "suburbs". Other features, including the main arms and the sun's location in the Orion Spur. Credit: NASA/JPL/Caltech/R.Hurt

The winter Milky Way doesn’t compare to the brightness of the summertime version. This has to do in part because of where the sun is located in the galaxy, some 30,000 light years away from the center, more than halfway to the outside edge. Yeah, we’re in the burbs. During winter nights, our planet faces the “outer suburbs” and rural fringe of the galaxy, where the stars thin out. In summer, we face inward and gaze across many more light years of stars and star clouds toward the center. Their combined light contributes to a much brighter Milky Way arch on summer evenings.

Few sky watchers have seen the winter Milky Way, either because of the cold or the effort required to find dark skies. We’re more likely to have caught a glimpse of the summer version, when the nights are conducive to walking or camping. If you’ve never had the pleasure of seeing the wispy, wintertime Milky Way flow past star-spangled Orion, don’t pass up the opportunity to see it . After all, do you want to live your life without having known the other half of our home galaxy?

The best time for viewing the Milky Way is when the moon is out of the sky from about 7 until 11 p.m. now through February 4 and again from 8 till 10 p.m. Feb. 19 through March 6. My recommendation? Put on every layer you own and get outta Dodge.

Will we see NASA’s giant orbiting kite?

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NanoSail-D, a 100-square-foot polymer sail, will be used to test solar sail technology. It's expected to remain in orbit 70-120 days. Credit: NASA

NanoSail-D, the experimental solar sail shot into Earth orbit late last year aboard the FASTSAT satellite, unfurled yesterday and began sending data packets back to Earth. The sail is an experiment in the use of sunlight pressure instead of the explosive power of rocket fuel to propel a craft across outer space. The 100-square-foot reflective “kite” might be visible with the naked eye or binoculars as it sails across the evening sky in the coming weeks. Amateur satellite trackers have yet to spot it, but that may be because its orbit isn’t precisely known. Once it is, you can find out if and when it’s passing over your location by checking out Spaceweather’s Satellite tracking page or logging in to Heavens Above. Below are some Central Standard times you can watch for it from the Duluth, Minn. region. Be aware, these times and positions are approximate; the satellite may be too dim to even see. Keep your binoculars handy! Instead of a general direction of where to look, I’ve given times when NanoSail-D will pass near easy-to-find stars. A minute or so before the pass, point your binoculars at these stars, wait and watch. To learn more the solar sail program, click HERE.

  • Tonight (Sat.) at 6:07:40 p.m. it will pass about one degree below the bright star Deneb at the top of the Northern Cross in the northwestern sky.
  • Sunday night at 5:13:30 to 5:14:30 p.m. the sail will glide about two degrees west of and parallel to the two stars that form the right or west side of the Great Square of Pegasus.
  • Monday night at 5:38:45 p.m. two degrees south of the center star in the Northern Cross.

An earlier H-II transfer vehicle or "space truck" held in place by the robotic arm. Credit: NASA

One satellite you’ll have no problem finding is the International Space Station (ISS), which is again making regular passes in the morning sky. The astronauts are getting ready for another cargo “truck” to pull up alongside the station for a delivery of supplies and parts. A Japanese H-II transfer vehicle, named “the white stork”, will launch today and rendezvous later with the ISS. It’s 33 feet long and 13 feet in diameter and packed with goodies like food, clothing, new computers and research equipment. Astronauts will use the station’s robotic arm to get a hold on the stork and berth it. This next shipment includes a specialized furnace for creating high-quality crystals from melting materials and an Agricultural Camera to take frequent photos of Earth’s vegetation in visible and infrared light.

Here’s when you can see the space station from the Duluth, Minn. region. For your town, click on the links above.

  • Tomorrow (Sunday) morning beginning at 6:23 a.m. across the southeastern sky. The station will nearly “touch” Venus at 6:25 a.m.
  • Monday Jan. 24 at 6:49 a.m. across the southern sky. A very nice bright pass.
  • Tuesday Jan. 25 at 5:42 a.m. low in the southeast. Second brilliant pass across the top of the sky in morning twilight at 7:16 a.m.
  • Weds. Jan. 26 at 6:08 a.m. Passes under the planet Saturn about 6:10 a.m.
  • Thursday Jan. 27 at 6:35 a.m. Brilliant pass high in the north that slices through the middle of the Big Dipper.
  • Friday Jan. 28 at 5:30 a.m. in the east – a brief appearance. Second showing across the north at 7:02 a.m.

The waning gibbous moon in January rises almost an hour and a half later each night. Created with Stellarium

Tonight the moon won’t rise until around 9 o’clock. Look for it well below Leo the Lion’s bright star Regulus in the east. The moon completes a full 360-degree cycle across the sky in just under a month, moving a little more than one fist held at arm’s length per day to the east. This nightly eastward march is a reflection of its orbital motion around the Earth.

Winter full moons are the highest full moons of the year, because they occupy the same spot in the sky the sun does at the beginning of summer. After full phase, the angle the moon’s path makes to the horizon is steep, so it drops quickly southward from its high perch. This means the moon rises substantially later each night. Tomorrow’s moonrise is at 10:30 – nearly 1 1/2 hours later than tonight’s. Other times of year, the most notable being during fall’s Harvest Moon, the angle of the moon’s path is less “steep” after full.  In September and October, successive moorises after full phase are only 15-20 minutes apart. Check out my Harvest Moon blog for a complete explanation.

With the moon rising well after nightfall, the stars return in full force. Tomorrow we’ll explore the winter Milky Way and stop by to visit the Orion Nebula.