Comet PANSTARRS pulls double-shift, gets no rest

Comet PANSTARRS flaunts a bright head and broad dust tail last night about 9:30 p.m. in the northwestern sky. Details: 200mm lens, f/2.8, ISO 800 and 32-second exposure on a tracking platform. Photo: Bob King

Comet PANSTARRS is finally visible again in a dark, moonless sky. It’s not easy to see with the naked eye, but still a cool sight in binoculars. I took a look last night from yet another roadside pullout where cars whizzed by like demonic fireballs every few minutes. What I wouldn’t give for a non-trafficked location with an clear view to the northwest. My wife told I should start knocking on doors and asking strangers if they wouldn’t mind me using their driveways.

Moonrise last night. The bright star above the moon is Spica in Virgo. With the moon now coming up well after dark, the next two weeks will be the best last time to see Comet PANSTARRS in binoculars. Photo: Bob King

The comet looked great in 10×50 binoculars with a broad tail about 2.5 degrees (five full moon diameters) long streaming back from a small, bright head. The photo captures the binocular appearance well. Since it first popped into the sky three weeks ago, PANSTARRS has faded from 0 magnitude (bright as Vega) to about 3.5, more than a level fainter than the stars of the Big Dipper.

But what it’s lost in brilliance, it’s made up for in altitude. Binoculars will show it about an hour after sunset some 15 degrees high (a fist and a half held at arm’s length) in the  northwestern sky. I kept it in view last night from 8:30 to 9:45 p.m. In twilight, only the head and a short bit of tail are visible, but as darkness descends and before the comet drops into the hazy horizon soup, you’ve got an hour of good viewing time. This is especially true for observers in the northern U.S. If you live “down south” your time is less.

Comet PANSTARRS hangs out in Andromeda the next week or so and passes near the Andromeda Galaxy around April 3. This map shows the sky about an hour after sundown facing northwest. Use the W of Cassiopeia to point you to Beta Andromeda. From there, drop to Delta and then to the comet. Maps created with Stellarium

PANSTARRS is moving northward across the constellation Andromeda with each passing night. Beginning this week, it’s making dual appearances – you can check it out during both evening AND morning twilight. If you’re an early bird, look low in the northeastern sky about 75 minutes before sunrise.

If you live in the northern half of the U.S. or Canada , you can now look for PANSTARRS low in the northeastern sky at the start of dawn. Once again, you can use the familar W of Cassiopeia to help get you there.  This map shows the sky about 75 minutes before sunrise.

By mid-April, our fuzzy visitor will have scooted far enough into the northern sky to remain visible all night long. Much like the Big and Little Dippers seen from the northern U.S. and Canada, it will circle around the pole star and never set. Astronomers use the term “circumpolar” for stars and other deep sky that cycle about the North Star without dropping below the horizon.

Around April 3 the comet will pass near the Andromeda Galaxy, the biggest galaxy closest to our own Milky Way. Like the comet, Andromeda is easily visible in binoculars and looks like a cigar-shaped patch of glowing fuzz with a brighter center. The pairing of comet and galaxy should make for a very interesting sight as well as offer an excellent photo opportunity for enterprising astrophotographers.

By the way, I’m now writing occasional articles for Universe Today. A recent one on this topic appeared yesterday if you’d like to check it out for a few more details and many additional photos.

Heads up – minor auroras out tonight March 28-29

An arc of northern lights materialized low in the northern sky shortly before 10 p.m. Central time tonight March 28. Photo: Bob King

Just got back from photographing Comet PANSTARRS and watching the moonrise. Shortly before 10 p.m. a dim auroral arc fanned across the northern sky about 10 degrees above the horizon. There were a few rays, too.

I was a little surprised because tonight’s activity wasn’t in the space weather forecast. I’m guessing it’s spillover from yesterday’s aurora caused by fluctuating speeds in the gust of particles from the sun called the solar wind. As far as I could tell, the aurora never showed here last night. Sky watchers at higher latitudes were more fortunate; a nice display graced skies over Finland, Norway and Alaska even in moonlight.

Photo taken about 10 minutes after the top image. A few rays joined the scene and the arc expanded a little further south and higher into the sky. Photo: Bob King

When the moon rose higher, the sky brightened and the lights faded back. Looking at the auroral oval, it’s expanding toward the northern U.S. as I write this around 11 p.m. Might want to take a look if it’s clear in case things take a turn for the brighter. The forecast calls for generally “quiet” conditions after tonight.

Cross the “snow line” to Saturn and relish its ancient ice

NASA’s Cassini spacecraft on July 29, 2011, shows Saturn’s A and F rings and five of its moons. From left, the moons are Janus, Pandora, Enceladus, Mimas and Rhea. Saturn is hidden at right behind Rhea. Credit: NASA/JPL-Caltech/Space Science Institute

Wipe the dust from an antique and you can begin to appreciate its vintage and workmanship. See beneath the space-worn colors of Saturn’s rings and moons and you might just get a glimpse of the primeval solar system. A new analysis of data from NASA’s Cassini spacecraft suggests that the Saturn system is tinted by “pollutants”.

Geysers of water ice crystals erupt from fissures in Enceladus’ south polar region in this photo taken by Cassini. Credit: NASA/JPL-Space Science Institute

The inner moons get whitewashed as they pass through water sprayed by geysers from the moon Enceladus. More distant moons wear a pale coating of red from particles of dust shed by Phoebe; the farther out they are from Saturn, the redder they appear.

Phoebe is an outer moon that may have once resided in the far-off Kuiper Belt beyond the planet Neptune before it was captured by the ringed planet.

Parts of the Saturn’s B-ring also appear faintly red perhaps from meteoroids that pepper the icy ring particles. Iron is a very common constituent of meteorites. Scientists think the reddish color could be either oxidized iron – better known as rust – formed when oxygen and iron combine in the presence of water -  or polycyclic aromatic hydrocarbons (PAHs), organic molecules common in tars and oil.

PAHs form in the atmospheres of aging, expanding stars when carbon and oxygen atoms are spat out into space. As they cool, the atoms bind together to form simple organic molecules and PAHs.

The precursors to the planets, called planetesimals, were mostly rocky stuff in the inner solar system within the snow or frost line. The outer planets formed from planetesimals composed of a mixture of rock and ice. Credit: Univ. of Colorado

Despite their diverse colors, data from Cassini’s visual and infrared mapping spectrometer (VIMS), which penetrates below the chemical veneer, found deep similarities. VIMS detected lots of water ice in both moons and rings, too much to have been deposited by recent comet collisions. The authors concluded that the ice must have formed around the birth of the solar system. How do you keep ice around that long? You either live in Duluth, Minn. or form it beyond the “snow line”, where temperatures are cold enough to keep things frozen almost forever.

Our solar system’s snow line starts at around 5 times the Earth’s distance from the sun or roughly at Jupiter’s distance. Indeed it’s the snow line which separates the inner terrestrial planets from the giant gas planets of the outer. Drop this side of the line and water either melts or vaporizes.

Saturn’s small 84-mile-long moon Prometheus creates a knot in the F-ring through its gravitational interaction with the icy ring particles. Prometheus may have formed from ring material. Credit: NASA/JPL-Space Science Institute

Cassini turned up another interesting fact. Saturn’s moon Prometheus has a similar reddish tint as the rings, hinting that it may have formed from ring material:

“The similar reddish tint suggests that Prometheus is constructed from material in Saturn’s rings,” said co-author Bonnie Buratti, a VIMS team member based at NASA’s Jet Propulsion Laboratory, Pasadena, Calif. “Scientists had been wondering whether ring particles could have stuck together to form moons — since the dominant theory was that the rings basically came from satellites being broken up.”

Saturn’s icy ring particles range in size from less than a millimeter to around 10 feet across. Credit: NASA/JPL-Space Science Institute

With Prometheus, the process may have worked the other way around, testing our assumptions once again.

Minor auroras possible tonight March 27-28, 2013

A fine aurora on the morning of March 17 this year from Duluth, Minn. Photo: Bob King

The NOAA space weather forecast puts the chances of a minor storm of northern lights for middle latitudes at 20% tonight. As of 7:30 p.m. Central Time the Kp index, a useful indicator of potential auroral activity, bounced up to “4″, a level below minor storm.

If the index moves into the red – “5″ or higher – that would be a hopeful sign.

I’m not saying we’re going to get auroras tonight just that the possibility exists. If they’re minor, not much may be visible anyway because the full moon comes up near the end of twilight. You may want to take a look all the same. Good luck!

Concealed planets exposed plus it’s spring break on Mars

The sun and its pack of planets photographed earlier today by the coronagraph aboard the SOHO observatory. The sun (white circle) is blocked by an opaque disk so astronomers can study the streaky solar atmosphere called the corona. Credit: NASA / ESA

Half the planets have gone into hiding. Mercury is too low in the dawn sky for northern hemisphere skywatchers, and Mars, Venus and Uranus are gathered around the sun concealed by its glare. Only Jupiter and Saturn remain available for our viewing pleasure.

Still, it’s hard to keep planets hidden away when you’ve got the eyes of the Solar Heliospheric Observatory (SOHO) on your side. SOHO orbits around a stable region of space called the L1 Langrangian point where the gravity of Earth balances that of the sun.

SOHO orbits about a million miles ahead of Earth in line with the sun in a small “halo orbit” around the L1 Lagrangian point. From this vantage point it keeps the sun and Earth in view 24/7. Credit: Office of Naval Research

From this prime observing spot, scientists use SOHO’s cameras to study the sun in many wavelengths or colors of light. Special devices called coronagraphs block the overly-bright solar disk with a metal stop to allow viewing of the sun’s outer atmosphere or corona. They also show other objects in the field of view like comets and the current gang of planets – Uranus, Venus and Mars.

Since the planets are very near one another, lots of interesting lineups will happen in the coming days. Venus reaches superior conjunction on March 28 (tomorrow) when it lines up on the opposite side of the sun from Earth. Six hours later it’s only one degree (two full moon diameters) below Uranus. An hour after, Uranus is in conjunction with the sun. Then on April 6-7 Venus and Mars will be in conjunction just half a degree apart. Is this beginning to sound like a barn dance?

One thing to remember about conjunctions – the planets involved are not physically close; they only appear to be because we see them in the same line of sight. If you’d like to watch all these interesting encounters, check out SOHO’s latest coronagraph image.

Approximately every 26 months, Mars passes almost directly behind the sun from Earth’s perspective. During this time, NASA will halt communications with the two rovers. Credit: NASA/JPL-Caltech

For us, Mars’ proximity to the sun is interesting but inconsequential. Not so for the Curiosity mission. On April 17 the planet is in conjunction on the opposite side of the sun from Earth. From our perspective, Mars will appear extremely close to the sun’s brilliant disk. Radiation from solar flares and high-speed subatomic particles in the sun’s corona can disrupt radio transmissions between the two planets during close alignments like this one. To prevent compromised radio commands from reaching either Curiosity or the older Opportunity rover, mission controllers will temporarily suspend transmissions from April 9 to 26.

Wide angle view of Yellowknife Bay taken by one of Curiosity’s hazard avoidance cameras on March 27, 2013. The rover recently resumed science operations after recovery from a computer glitch. Credit: NASA/ JPL

Communications from Mars to Earth will also be reduced. To stay in touch, Curiosity will send daily beeps to Earth. Meanwhile both rovers and orbiting Mars satellites will continue science operations. Data gathered will be stored and then beamed to Earth in early May. The rovers’ spring break will be tame by earthly standards; both will stay put during the interval to prevent any shenanigans.

The bright star Sirius and planet Jupiter perform a balancing act on either side of Orion’s Belt this month and next. This may shows the sky facing southwest around 8:30 p.m. in late March.  Maps created with Stellarium

Did I mention there are still two great planets out at night? Jupiter stands high in the west-southwest at nightfall. It’s the brightest object in that direction. Saturn comes up later around 11 o’clock in the southeast about one extended fist to the lower right of Spica. The full moon will be near Spica tonight and Saturn on Thursday night. Much to see for all!

The full moon will swing by both Spica (tonight) and the planet Saturn tomorrow night. This map shows the sky facing southeast around 11:30 p.m.

Worms, crows, maple syrup and the moon illusion

Tonight – and tomorrow night – the Full Worm moon will rise in your neighborhood. Be sure to catch it. Photo: Bob King

The March full moon goes by a variety of names, all appropriate in their own way in this month of seasonal transition. Full Worm Moon. Crow Moon. Sap Moon. Even Crust Moon to describe the icy crust that forms on snow overnight after a day of above freezing temperatures. These were the names given by Indian peoples across the country to tonight’s full moon.

Your calendar may show tomorrow the 27th as the date of full, but since the moon is “fullest” around 4 a.m. Wednesday Central time, it will appear slightly fuller tonight than tomorrow, at least for sky watchers in the western hemisphere.

Most of us won’t be able to tell the difference anyway with our eyes; such subtleties are reserved for binocular and telescope users.

I’ll bet you’ve witnessed the famous moon illusion sometime in your life. When near the horizon, the rising or setting moon looks HUGE compared to when it’s higher up in the sky. Our logical self knows the moon can’t really be bigger. Matter of fact, it’s actually very slightly smaller, since we have to look around the curve of the Earth to see it at moonrise.

How big does the moon look to you when near the horizon? This illustration shows the impression shared by many – the rising moon appears bigger. Illustration: Bob King

If you photograph the moon near moonrise and then again when it’s high up and measure its size, you’ll find there’s no difference in diameter.

Generations of philosophers and scientists at least as far back as Aristotle, who believed it was magnified by the thick air near the horizon, have tried to get to the heart of why we see it so. Our best current explanations to explain this persistent illusion are the “relative size” and “oculomotor micropsia/macropsia” theories.

Relative size is easy to understand and based on the perceived size of an object relative to objects near it. Trees and buildings in the nearby distance and sharing the horizon with the moon make it appear larger in our brains.

When the moon ascends higher and is surrounded by a large expanse of empty sky, it appears smaller. Psychologists call it the Ebbinghaus Illusion and it’s all about context.

An illustration of the Ebbinghaus illusion. The two orange circles are exactly the same size, yet the one on the right appears larger. The left side demonstrates seeing a full moon in large areas of open sky; the other simulates seeing it in the company of many smaller foreground objects. Credit: Wikipedia

Take a look at the illustration above and you’ll see what I mean by context. Assuming the relative size explanation is correct, one could perform an interesting test by comparing the moon’s apparent size in a busy setting with lots of visual cues to one viewed across an empty field or open lake. Would the illusion disappear in the latter?

Now let’s get acquainted with oculomotor micropsia/macropsia. This lovely bit of terminology provides a physical explanation for the illusion and boils down to this:

* When you look at the moon and then momentarily converge your eyes to focus on closer objects in the landscape, the moon will appear smaller (micropsia) than it was before. If you then glance back at the distant moon, your eyeballs straighten out and the moon’s apparent size becomes larger (macropsia).

We’ve all seen the afterimage of a camera flash suspended in front of us after getting our picture taken. If you recall, the afterimage looks large against a wall on the other side of the room, but if you were to hold your hand in front of your face, the ghostly flash would appear small.You can simulate a camera flash by staring at a bright light for a minute in a semi-darkened room and then looking away.

The human eye is our portal to both the real world and one of illusion. Photo: Steve Jurvetson

Consider trying an experiment described by Don McCreedy, professor emeritus of psychology at the University of Wisconsin-Whitewater, when you’re watching the full moon tonight. Cross your eyes by looking at the bridge of your nose while at the same time paying attention to the moon in front of you. While the moon will be blurred, it should look smaller. Then uncross your eyes and stare at the moon – it will immediately look larger.

Scientists are still working on the ultimate explanation for the moon illusion. For now, it appears to be a combination of both the relative size effect and micropia/macropsia. If you really want to dig into the details, you’ll find much to learn at McCreedy’s Moon Illusion Explained site. To find times when the moon rises for you town tonight, click HERE.

Have fun and don’t get your eyes stuck :)

Comet PANSTARRS grows fan-tastic tail

Italian amateur astronomer Lorenzo Comolli captured beautiful symmetric rays called synchronic bands in the dust tail of Comet C/2011 L4 PANSTARRS on March 21, 2013 through his 5.5-inch refracting telescope. Credit: Lorenzo Comolli

I know. You’re probably got PANSTARRS fatigue. Still, I can’t help but direct your eyes once again to yet another wonderful photograph, this one made by Italian amateur astronomer Lorenzo Comolli. Like many of us, he lives in a light polluted area and must escape to find darker skies. For Lorenzo that means a trip to the Alps or Apennines.

Lorenzo with the scope he used to photograph the comet. Credit: Lorenzo Comolli

His spectacular image was made using a 5.5-inch (140mm) wide-field refractor, a sensitive CCD camera and seven images. Each exposure lasted 2 minutes during which time he carefully guided the telescope to follow the comet’s motion across the star field. Lorenzo then stacked all seven images one atop the other in an photo program like Photoshop to create a single, high resolution photo.

Astrophotographers prefer stacking a series of short-exposures instead of making one long exposure because it reduces noise (graininess) and the effects of light pollution. A 14-minute time exposure picks up more unwanted light than a 2-minute one.

Lorenzo added this information to his photo of PANSTARRS. The main tail is composed of very tiny dust particles; the short tail to the left, which tracks along the comet’s orbital path, is formed from the largest, heaviest dust bits. Credit: Lorenzo Comolli

Studying the picture we’re struck by the fan-like spread of multiple plumes of dust released by the comet as the heat of the sun vaporizes dust-laden ices. Cometary dust particles are extremely small, ranging in size from less than a micron (equal to one-thousandth of a millimeter) to 1/100 of a millimeter. For comparison, particles in wood smoke fall in the same range. Sunlight pressure physically pushes these tiny motes back to form the tail.

The real eye-catchers are the synchronic bands. Our best model points to their formation from individual fragments or chunks that break up once they’re released from the comet. As each new fragment crumbles into fine dust, it’s raked into a fresh by sunlight. I think you would agree the end result of such a simple process is breathtaking.

Comolli’s picture also records a dim tail made of sodium atoms, possibly released by collisions between dust grains flying off the comet’s nucleus, and a second dust tail of larger particles trailing behind the comet as it moves along its orbit around the sun. For more of Lorenzo’s images of Comet PANSTARRS, click HERE.

I’ve labeled the different parts of Comet PANSTARRS tail using information from Uwe Pilz on dust particles sizes. Cigarette smoke is 0.01 to 1 micron in size, a level or two smaller what we see for dust in comets. Credit: Lorenzo Comelli

Uwe Pilz of Leipzig, Germany has created a wonderful series of simulations of PANSTARRS’ tail that reveal how dust particles are sorted according to size across the comet’s multiple tails.

I’ve used his information to help you see what’s where in Lorenzo’s photo. Again for reference, a typical bacterium is between 0.2 and 3 microns across (same  as fine comet dust!), a human red blood cell 5 microns and a human hair is about 75 microns but varies by hair type.

While most of us will never see such such riches through our telescopes and binoculars, we can appreciate this hidden side side of PANSTARRS that superb amateur photography can reveal.

Hey, where are all the Milky Way supernovas?

The scene witnessed by Johannes Kepler after sunset on Oct. 17, 1604. While he wasn’t the first to see the supernova, Kepler studied it like no one else. To recognize his detailed observations, we now call it Kepler’s Supernova. Created with Stellarium

Hard to believe it’s been over 400 years since anyone’s seen a supernova in the Milky Way galaxy. Amateur and professional astronomers spot them all the time in galaxies external to our own. In 2012 alone 1,048 supernovas were discovered thanks to numerous, mostly-automated searches that photograph hundreds of galaxies each night looking for signs of exploding stars. Given such a large sample, it should come as no surprise that dedicated supernovae searches turn up these “new stars” routinely.

Johannes Kepler in 1610

The last person to see one with his own eyes was astronomer Johannes Kepler, famous as the first person to explain the Laws of Planetary Motion. The new star blazed forth on October 9, 1604 in southern Ophiuchus, a summertime constellation visible in the southwestern sky during early fall. Observing from Prague, overcast skies prevented his from seeing it until the 17th.

When the clouds parted, Kepler got an eyeful. The supernova, which soon waxed as brilliant as Jupiter (mag. -2.5), shone in the company of three bright planets – Mars, Saturn and Jupiter. He must have been beside himself with amazement at the gathering of so many shiny objects together in one corner of the sky.

Kepler relentlessly observed the new star every clear night until at dusk and in the winter months at dawn until it finally faded from view in March 1606. Not long after, he penned a book with his observations titled De Stella Nova. In it Kepler compared the new star with the Star of the Magi and speculated that it might lead to the conversion of the Indians in America. You can flip through a digital version of the tome HERE.

Only 3 years later Galileo would turn one of his early telescopes to the sky. Had the telescope been invented just a few years earlier, Kepler could have continued his supernova observations much longer.

The expanding supernova remnant Cassiopeia A is located near the place John Flamsteed recorded a star in 1680. Working back from the currently observed expansion point to an explosion indicates the supernova would have been visible in the sky around 1667. Photo made with the Hubble Space Telescope. Credit: NASA / ESA

In 1680 English astronomer John Flamsteed recorded a faint 6th magnitude star in the constellation Cassiopeia during his compilation of a new star catalog. Labeled 3 Cassiopeiae, the star was omitted from later catalogs since it couldn’t be found again. 300 years later astronomers discovered a faintly-glowing husk of light called a supernova remnant – the leftover, expanding clouds of gas and debris near the position of Flamsteed’s star. It’s possible he may have seen it during its explosive phase or simply made a mistake in a star position.

Composite of photos showing an all-sky view of the Milky Way. The dark blobs are cosmic dust within the galaxy that blocks the light of stars behind it. Copyright: Axel Mellinger

Previous to Kepler’s supernova was the great daylight supernova of 1572 studied by Kepler’s mentor Tycho Brahe. That’s two in 32 years and nothing since. What gives? Astronomers estimate a star goes boom in the Milky Way galaxy about once every 50 years. Shouldn’t we have seen another in 400 years? Blame it on cosmic dust.

Stardust shed by supernovae and through gentler means permeates space and concentrates in the plane of the galaxy where most of the Milky Way’s approximately 400 billion stars reside. To stare across a few light years of space, you’d never notice it. But over hundreds of light years the dust adds up, effectively screening billions of stars from view and greatly reducing chances of seeing a supernova anytime soon.

Supergiant stars like Betelgeuse in Orion and Antares in Scorpius are both extremely large and extremely rare.

There’s another factor, too. One class of supernovas, called Type II, happen when a supergiant star runs out of fuel to burn. With no heat to hold back the inward pull of gravity, it implodes and then explodes.

These monsters are rare. 80% of stars are tiny, long-lived red dwarfs; 3.5% are stars like our sun and supergiants account for measly 0.001% of known stars. With so few to pick from and dust an issue, it’s yet another way the odds are stacked against seeing a local supernova.

Radio images made by the VLA of supernova remnant G1.9+0.3 show it expanding about 15% over a period of 23 years. Credit: NRAO / VLA / D. A. Green

Not that the galaxy’s been slacking off. The most recent Milky Way supernova was announced in May 2008 by a team of astronomers using the dust-busting Very Large Array (VLA) radio telescope in New Mexico, and confirmed in X-ray images from the Chandra X-ray Observatory in orbit. Both telescopes study the sky at wavelengths of light than can penetrate dust to see what lurks beyond.

G1.9+0.3 is another supernova remnant like Cas A – the expanding remains of the exploded star. It’s located close to the center of the galaxy and utterly obscured from visual view by thick clouds of interstellar dust. Working backward from now to the point of explosion, astronomers estimate the star went supernova about 140 years ago. Were it not for dust, citizens of the Victorian era would have marveled at their new star.

This is the remnant of Kepler’s Supernova. The red, green and blue colors show low, intermediate and high energy X-rays observed with NASA’s Chandra X-ray Observatory, and the star field is from the Digitized Sky Survey. The remnant resulted for Type Ia explosion, where a tiny, dense white dwarf star pulls material from a close companion star onto its surface, becomes unstable and explodes. Other supernovas happen when a supergiant star runs out of fuel at the end of its life and implodes-explodes. Click photo for more info.  Credit: NASA/CXC/NCSU/M.Burkey

Somewhere out there a Milky Way star has self-destructed in a supernova explosion. Light from the cataclysm is streaming our way at this very minute. Will it pass unscathed and surprise us tonight or be foiled by dust once again?

Don’t give up on Comet PANSTARRS yet

Comet C/2011 L4 PANSTARRS last night March 22, 2013 at 8:40 p.m. low in the northwestern sky. Although faint, it was still seen with the naked eye and remains a pretty sight in binoculars. Details: 200mm at f/2.8, ISO 400 and 15 sec. exposure on a tracking mount. Photo: Bob King

We’ve had a good week for Comet PANSTARRS watching in my region. I hope you’ve also had an opportunity to go out for a look. Three clear nights with fine binocular views presented themselves.

The first night the wind blew at 30 mph and I could barely keep the telescope from spinning around; the second was absolutely calm but I never got the focus right on my camera and the third – last night – was sweetest. I set up a camera under the bright gibbous moon on a frozen bog used as a snowmobile trail. Bright moonlight lit the snow and air in such a cheery way, I felt I didn’t have a care in the world.

The highlight of seeing the comet through the telescope was its brilliant, pea-like false nucleus glowing yellow from sunlit dust. The real comet nucleus – the actual comet – lies within the false nucleus and shrouded by dust. Drawing: Bob King

Even in moonlight the comet was faintly visible with the naked eye once you knew exactly where to look. I could distinguish its small, brighter head glowing around 3rd magnitude (one level fainter than the stars of the Big Dipper) and a faint streak of a tail. Through 10×50 binoculars the tail pointed straight up and stretched some 2 degrees (four full widths). I kept the comet in view from 8:10 to about 9 p.m.

Use this map to find Comet PANSTARRS now through March 29. The map shows the sky facing northwest about 40 minutes after sunset when the comet will be a little more than one “fist” high. Created with Stellarium

You can use this map to help you find PANSTARRS. It shows the sky for mid-northern latitudes about 40 minutes after sunset. For my town, that’s around 8:10 p.m. Because the comet has finally risen high enough in the west to appear in a darker sky and headed toward a group of brighter stars, we can use some of those stars to help us find it.

You can start as far up as Jupiter if you like and draw a line to the north (right) to Mirfak, the brightest star in Perseus the Hero. From Mirfak, drop down to Gamma Andromedae and then to Beta and almost to Alpha. That puts you right next to the comet. Or you can shoot a line from the bottom of the W-shaped constellation Cassiopeia straight to Beta and from there to PANSTARRS.

Late next week, when the moon is out of the sky, we’ll finally see the comet at least briefly in real darkness. I’ll prepare two maps – one for evening and another for morning – that you can use to continue tracking it. Yes, PANSTARRS will be visible at both dusk and dawn especially for sky watchers in the northern states, Canada and central Europe. At the start of April, watch for it to pass just under the Andromeda Galaxy, a chance juxtaposition with excellent visual and photo potential.

The comet joins an old white pine tree in this scene from March 19. Details: 300mm lens at f/2.8. ISO 800 and 5-second exposure. Photo: Bob King

While PANSTARRS never became a great naked eye comet for northern hemisphere observers, it could rightly be called a great binocular comet. Bright twilight and low altitude have proved major obstacles for would-be seekers.

Were it only well-placed in a dark, nighttime sky, many more people would find it with ease.

I encourage you to stick with our space visitor and give it another try. Don’t expect a naked eye feast but do anticipate an inspiring sight in telescopes and binoculars for the next few weeks.

The Universe – 100 million years older but just as vibrant

A map of the entire sky by the Planck space observatory of the oldest light in the universe. The range of colors represent tiny temperature variations in the light. These acted as “seeds” that led to the formation of the first stars and galaxies. Hotter regions are red; cooler spots are blue. Planck can sense temperature variations of a few millionths of a degree. Credti: ESA

The Planck spacecraft has discovered that the universe is 100 million older than previously thought. Earlier estimates pegged it at 13.7 billion years. Another 100 million would make it 13.8 billion years old. If I’ve done the math right, that’s 0.7% older. Crunched down to human scale, that would be like waking up today at age 30 and discovering you were suddenly 72 days older.

Planck is a joint European-U.S. venture launched in 2009 to extend the highly successful COBE and WMAP missions that provided astronomers with their first maps of the cosmic microwave background (CMB). Located in a stable region of space called the L2 Lagrangian point, Planck has mapped the CMB in even greater detail since 2010.

Model of a carbon atom which has six positively charged protons, six neutral neutrons and six electrons. Hydrogen, the simplest element, has one proton and one electron. Credit: Universe Today

When the universe initially formed, it was microscopic, incredibly hot and contained only energy and space. During the first three minutes it expanded and cooled enough for energy to “congeal” into protons and neutrons, the subatomic particles we know as the building blocks of atoms. These in turn collided to form the simplest atomic nuclei of hydrogen, helium and a trace of lithium.

While the initial temperature of the universe was essentially infinite, matter (atoms) formed when it had dropped to a more pleasant 1.7 billion degrees F. This was still too hot for electrons, those tiny particles that whiz around the nucleus of an atom, to “stick” to the newly formed atoms.

Timeline of the universe from the beginning of time and space in the Big Bang to the formation of the CMB. This wasfollowed by a 400 million-year-long Dark Era before the first stars and galaxies formed. Clicking the image will take you to a step-by-step illustrated timeline. Credit: Rhys Taylor, Cardiff University

For the next 380,000 years, even as temperatures continued to plummet, the universe, with all of its expanding space, energy, nuclei and free-roaming electrons was a dense, impenetrable fog called a plasma. The soup of particles was so thick that photons (particles of light) trying to stream away from one nucleus or electron was immediately scattered away by its neighbor. Light was going nowhere.

Had you been around back then the entire universe would have been a dense cloud, the kind you often fly through in a plane but so thick you wouldn’t have seen your hand in front of your face.

The very early universe had slightly cooler and hotter (denser and less dense) regions where the first matter collected that some 400 million later would condense and ignite to form the first generation of stars. Credit: NASA

At 380,000 years a major transition happened. Things cooled down to around 28,000 degrees allowing electrons to settle into orbit around the hydrogen and helium nuclei to form neutral atoms. Bound to the nucleus, electrons weren’t available to scatter photons of light anymore. Like a prisoner set free, light streamed unimpeded across the universe for the first time. This ‘”first light” is the cosmic microwave background radiation. The fact that we see it is one of the best proofs the Big Bang really happened.

Graphic illustrating the evolution of satellites designed to measure ancient light leftover from the Big Bang that created our universe 13.8 billion years ago. Called the cosmic microwave background, this light reveals secrets of the universe’s origins, fate, ingredients and more. Credit: NASA/JPL-Caltech/ESA

The Planck map reveals tiny variations in the temperature of that light. These result from what are called quantum fluctuations in the universe present in the moments after its birth. Without getting into fancy physics, they’re changes in the energy content of various points in space that vary chaotically. Those energy “bumps” were frozen into the fabric of space once the expansion ramped up and the first neutral atoms formed.

Billions of years later we see these original fluctuations writ large as temperature variations mapped by Planck. Seen as splotchy hot and cold spots in the Planck map, they’re seeds where matter collected in the early cosmos and grew into the stars and galaxies that populate the universe today.


So you see, the map really shows the origin of matter from jittery, fluctuating energy states of empty space. It’s a relic of the distant past embedded in the first light to grace a fresh-faced universe. The map also suggests the universe is expanding more slowly than originally thought, hence its older age estimate. And there’s more:

“As that ancient light travels to us, matter acts like an obstacle course getting in its way and changing the patterns slightly,” said Charles Lawrence, the U.S. project scientist for Planck at NASA’s Jet Propulsion Laboratory in Pasadena, Calif. “The Planck map reveals not only the very young universe, but also matter, including dark matter, everywhere in the universe.”

Toting it all up, the new estimates for the composition of universe include 4.9% normal matter (up from 4.6%), 26.8% dark matter (up from 24%) and 68.3% dark energy (down from 71.4%). Determining exactly what makes up dark matter, which has gravitational pull but can’t be seen since it emits no light, and dark energy, a repulsive force causing the rate of the universe’s expansion to speed up over time, are both fields of active research.

As I look out at today’s blue sky, hear the sound of voices from the street and admire Comet PANSTARRS at dusk, I’m convinced this universe has aged that extra 100 million years with grace.