Tag Archives: comet

Comet PANSTARRS for die-hards

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Comet PANSTARRS climbs toward the North Star through Cepheus the King in the coming nights. It passes close to Gamma Cephei May 12-14, making it easy to find. Click map for a completely updated finder map and more details. Stellarium

Some of you have asked about a new map for locating famed Comet L4 PANSTARRS as it treks through Cepheus headed for the North Star. Well, here ya’ go. PANSTARRS currently shines around magnitude 7 and should still be easily visible in 50mm or larger binoculars as a faint fuzzy spot with perhaps a hint of tail. The comet’s visible all night long for observers at mid-northern latitudes. Share your impressions with us via Comments if you see it.

Comet PANSTARRS x 2 and the Pan-STARRS asteroid survey

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The Andromeda Galaxy (left) and Comet C/2011 L4 PANSTARRS last night about 9:20 p.m. The tail fans out broadly in the galaxy’s direction. To the left of the comet’s head is a sharp, stub of a tail made of larger dust particles that fall along the comet’s orbit. Details: 300mm lens, f/2.8, 90-second exposure on a tracking mount. Photo: Bob King

I’m sorry but Comet PANSTARRS just won’t quit. Under clear skies last night both it and its new-found companion, the Andromeda Galaxy, were dimly visible with the naked eye, with the comet the brighter. PANSTARRS continues to impress in binoculars – I use 10x50s – and the sweeping curve of its tail and bright nuclear kernel are very pretty through the telescope. It’s a joy to finally see it now in a dark sky. Click HERE for a map to find the comet yourself.

Comet PANSTARRS moves along a steeply tilted orbit that takes it far above and below the plane of the planets. Right now it’s high above Earth’s north pole and we its tail broadside. The comet takes about 106,000 years to complete an orbit around the sun. Credit: NASA/JPL/Bob King

PANSTARRS loops high above the plane of the solar system presenting a broadside view of its impressive tail. I can’t recall a comet with a tail that looks so much like a sail as this one. The brightest section of the dust tail points north-northeast but fans open all the way ’round to due east and even a little beyond. That’s a spread of more than 90 degrees.

The comet continues to fade to be sure – it’s now around 4.5 magnitude – but the beauty of its form is barely diminished.

The prototype Pan-STARRS telescope is housed in a dome at the 10,000 foot summit of Haleakala in Hawaii. Credit: Brad Simison

PANSTARRS was discovered by the Panoramic Survey Telescope & Rapid Response System (Pan-STARRS) based at the University of Hawaii’s Institute for Astronomy. Right now the University is using a prototype 70.8-inch (1.8-meter) telescope that’s basically one-quarter of the Pan-STARRS system that when completed will feature four 70.8-inch scopes. They’ll simultaneously photograph 3-degree patches of sky all night long every clear night and download the pictures automatically into a computer. The primary goal of the project is to search for and find asteroids that could pose a potential hazard to Earth.

Not only did the survey discover our current comet celeb but it’s found others including P/2012 B1 PANSTARRS, a dim comet ambling through the constellation Virgo at the moment.

This photo taken April 4, 2013 of Comet P/2012 B1 PANSTARRS shows a streak of a tail, small bright nucleus that looks like a star and a short “anti-tail” from material boiled off by the sun and left behind in its orbit. Credit: Damian Peach

The “P” in the name stands for “periodic” meaning it makes regular returns to the inner solar system. B1′s period is 16.9 years and it’s currently 270 million miles from Earth, much farther than its big brother. But at least we won’t have to wait 106,000 years for its return!

Don’t give up on Comet PANSTARRS yet

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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.

Finally … a beautiful Comet PANSTARRS night from Duluth, Minn.

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Comet C/2011 L4 PANSTARRS around 8:20 p.m last night March 16 from north of Duluth, Minn. Details: 300mm lens at f/2.8, ISO 1600 and 4-second exposure. Photo: Bob King

We’ve waited 10 nights for clear skies in the Duluth, Minn. region and last night was the charm. Clouds cleared out in the nick of time leaving the western sky open for a freezing-room-only performance by the comet of the hour. The winds whirled snow across the road and shook the tripod but did nothing to dampen that internal flame that keeps all cold at bay.

I first saw PANSTARRS a little after 8 p.m. higher in a bluer sky than I expected. The comet looked white with a bright head and short tail easily seen in 10×50 binoculars. Minutes later I was surprised to see it with the naked eye. The comet looked like a dim star in bright twilight; I estimated its brightness at 1.0 magnitude.

This is very much how the comet looked with the naked eye and binoculars last night shortly after 8 p.m. Details: 180mm lens at f/3.5, ISO 800 and 1-second exposure. Photo: Bob King

As the comet sunk lower, the sky darkened and I could faintly see the tail using averted vision, a technique of looking at something out of the corner of your eye instead of directly at it. If you didn’t know where to look, you’d probably not even know PANSTARRS was there, but once you fixed your eyes on it, it was obvious.

Binoculars showed a graceful, curving tail 1.5 degrees long or equal to three full moons side-by-side. The head was very bright and pale yellow. At this point I was attempting to find a pullout on heavily snowed-in roads to park my car. I even tried a snowmobile trail until five guys road up, headlights ablaze, and indicated it was time to move on. With all the snow in our region, the toughest part about finding the comet was securing a comfy spot with a view down to the horizon.

I watched as PANSTARRS dropped lower and lower until atmospheric haze masked it from the naked eye. Binoculars continued to give great views until a distant cloud put the kibosh on the outing.

I loved the adventure of finding the comet and was struck by how pretty it appeared in simple binoculars. Many evenings of comet viewing remain. Those living in the northern U.S. will soon be able to spot PANSTARRS in both the evening and morning skies. More on that in due course. Have fun, enjoy the adventure.

STEREO beams back stunning new PANSTARRS pics

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STEREO-B photo of Comet PANSTARRS along with planet Earth taken March 13 and processed by Alan Watson. The two vertical white lines are electronic artifacts. Credit: NASA

I thought the first STEREO-B pictures of C/2011 L4 PANSTARRS joined by planet Earth were sweet enough enough. No, no. This one – and the accompanying video – are far nicer. They were made on March 13 when PANSTARRS had more fully entered the telescope’s field of view.

STEREO-A and STEREO-B are twin NASA space probes that study the farside of the sun invisible from Earth stereoscopically. They orbit ahead and behind our planet in its orbit. STEREO-B looks back toward the Earth and comet from its current position in orbit. The diagram show the inner solar system viewed from above Earth’s north pole. Credit: NASA

Relish the many plumes striping the comet’s broad dust tail. Astronomers call them “striae” (STRY-eye or STRY-ee), and they result from the release of massive amounts of dust from vaporizing cometary ices. As they’re blown back by the pressure of sunlight to form the tail, the particles get sorted out into individual plumes according to their varying sizes. Let’s hope that once PANSTARRS gets high enough to see in a darker sky, the beautiful striae will reveal themselves.


STEREO-B video of Comet PANSTARRS and a blast from the sun

The video was compiled using multiple single frames from STEREO-B. The field of view is about 20 degrees (about as wide as the constellation Orion is tall) and the sun is out of the field of field. STEREO-B orbits on the opposite side of the sun from Earth and looks back toward the comet which is fortuitously lined up with the Earth. Amping up the excitement another notch, a coronal mass ejection from the sun appears to be headed for the comet. This is a trick of perspective – the blast missed PANSTARRS by some distance.


Another animation of the comet from March 13 STEREO-B images. Sun is off to the left.

Speaking of distance, you’ll see in the lower left of the orbital diagram that STEREO-B is 1.9 A.U. from Earth. An A.U. or astronomical unit is equal to Earth’s distance from the sun or 93 million miles, so the spacecraft is currently about 177 million miles from our planet. PANSTARRS meanwhile is 1.1 A.U.s from Earth (102 million miles) and very approximately 75 million miles from STEREO-B.

Heads and (many) tails. Comet PANSTARRS on March 15 from Valley Forge National Park, Penn. Credit: John Chumack

I only toss these figures out so you can appreciate the enormity of the comet’s dust tail. The Earth barely registers as more than a blip in the picture. Even accounting for PANSTARRS being some 40% closer to STEREO’s camera than Earth, the tail measures at least a million miles long. Compare that to Earth’s 8,000-mile-diameter and you can begin to appreciate its size.

Comet Hyakutake, which was strode across the spring sky in 1996 had one of the longest tails on record: 354 million miles (570 million km). Credit: NASA

Since comet tails aren’t solid objects, the amount of mass they contain is very small despite appearances. Indeed, they put on a good show!

Comet Hyakutake

Tough time finding Comet PANSTARRS? Crescent moon to the rescue!

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Comet C/2011 L4 PANSTARRS over the lights of San Diego, Calif. on March 10, 2013. Kevin caught the comet in an open spot between bands of haze. Credit: Kevin Baird

Comet PANSTARRS is proving harder to see with the naked eye than expected. Many sky watchers have either been thwarted by clouds or frustrated by haze. Even hard-core comet followers have had difficulty, so you’re not alone. While most experienced observers estimate its brightness at about 1st magnitude – equal to that of the brighter stars – haze, clouds and bright twilight have made finding it with the naked eye tricky to impossible to see.

The 1-day-old moon lines up with PANSTARRS in the western sky tonight March 12.. This map shows the sky from mid-northern latitudes about 25 minutes past sunset when the comet and moon will both be 8 degrees high slightly south of due west. Maps created with Stellarium. See end of blog to learn how to get this free program and make your own comet map.

OK, now for the good news. We’re all going to get some help tonight and tomorrow night from the crescent moon. Like a celestial fishing guide, the moon will take you to the right spot where all you need do is drop your line in the water and wait for a bite. We’re hoping your patience nets you a comet this time around.

Tomorrow night March 13 the moon will be higher and easier to see and still be useful to locating the comet. This map shows the sky about 25 minutes after sunset looking west. The moon will be 20 degrees high, the comet 10 degrees.

Tonight (March 12) look about 4 degrees to the left of the moon with binoculars beginning about 25 minutes after sunset. Assuming the sky is clear, you should see a fuzzy pinkish star. Trouble focusing? Just point the binoculars at the moon and focus sharply. You can also use clouds for focusing. Either way, once they’re sharp, the comet will be too.

As the sky darkens, the “star” will sprout a short tail. That’s it – Comet PANSTARRS. The color by the way is not intrinsic to the comet but caused looking through so much thick atmosphere. It’s the same reason the sun and moon glow red when near the horizon; blues and greens are scattered by dense and dusty air, leaving only oranges and reds. The comet-moon combo should be visible for about a half hour until setting.

Tomorrow March 13 the moon will be further up and easier to see but still near enough the comet to once again serve as an able guide.

A pair of binoculars along with the moon should help you find Comet PANSTARRS tonight. Credit: Kevin Baird

Again, I can’t emphasize enough how useful binoculars are in extending the reach of your vision. For many, they’re absolutely necessary to get a fix on the object in the first place. Once found with binoculars, PANSTARRS with be easier to pin down with the naked eye because you’ll know exactly where to look. 7×35, 7×50, 10×50 or 8×40′s combine ease of use with good light-gathering capability and are widely available.

Comet PANSTARRS caught in a clear gap between clouds yesterday March 11 from Austria. Credit: Michael Jaeger

Once found with binoculars, you’ll find it easier to pick out PANSTARRS with the naked eye because you know exactly where to look. 7×35, 7×50, 10×50 or 8×40′s combine ease of use with good light-gathering capability and are widely available.

I wish I could share my own impressions of PANSTARRS, but it’s been completely overcast here for the past five nights and the next few don’t look any better. Needless to say, I’m chomping at the bit.

By the way, I dug around and discovered how to show the comet’s exact location in the free sky charting software program Stellarium, which is what I used to make the charts in today’s blog.

First, download either the Mac or PC version HERE. Then follow these instructions, provided by Bogdan Marinov with addition tweaks by yours truly. I apologize for the length; readers not interested in plotting the comet’s location can ignore this next section.

Finding a comet with Stellarium

1. Enable the Solar System editor plug-in by clicking on the Configuration window (it will appear as a little box with a wrench icon if you move your pointer to the lower left of the screen.) It will also pop up if you hit “F2″ on your keyboard.
2. Open the Configruation window and go to “Plugins”
3. Select “Solar System Editor” in the left column (the plug-in’s description should appear)
4. If the “load at startup” box is not checked, check it and restart Stellarium.
3. Go to the same plug-in screen, select the same plug-in and click on the “configure” button.
4. In the window that opens, go to the “Solar System” tab, then click on the “Import elements in MPC format window”.
5. In the window that opens, select “Comets”, then “Download a list of objects from the Internet”.
6. If you are using 0.10.6, copy this URL to the “URL” box: http://www.minorplanetcenter.net/iau/Ephemerides/Comets/Soft00Cmt.txt
7. If you are using 0.11.0 or higher, just select “MPC’s list of observable comets” from the bookmarks list.
8. Click the “Get orbital elements” button and wait for the file to be downloaded.
9. After it has finished downloading, it should display a list of comets. Find the comet you want to add in the list, check the checkbox in front of it and click the “Add objects” button. In this case, look for C/2011 L4 (PANSTARRS).
10. After the comet has been added, you can find it in the “Search” window: start typing the name of the comet for it to appear in the list of suggestions. The name should be written in the same way as it was displayed in the list as C/2011 L4 (PANSTARRS)
11. Now put in the time and place you want to see the comet and select a horizon with no obstructions. The “Ocean” or “Guereins” views are best. You’ll find them under  ”Sky and Viewing Options window/Landscapes”.

It may not show up at first because of the bright twilight sky. To “force” it to appear, go to the “Sky and Viewing Options” box by moving your pointer to the lower left of the screen or hit “F4″. In the “Light Pollution” box, click down to “1″, the least amount of light pollution. The comet should now show up as a point of light just like a star. If not, advance the time a few minutes until the sky gets dark enough for PANSTARRS to appear.

Will a comet clobber Mars next year?

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Photo illustration of a comet passing near Mars in 2014. Credit: Comet R1 McNaught by Michael Jaeger; Mars photo by Emil Kraaikamp

On January 3, 2013 comet C/2013 A1 was discovered photographically by Robert McNaught at Siding Spring Observatory in Australia. At the time it was over 7 times farther than Earth from the sun and extremely faint. Though far from Earth’s perspective, this dusty dollop of ice had probably been on its way from the Oort Cloud, a massive and distant comet repository at the fringe of the solar system, for millions of years.

Comet C/2013 A1′s orbit cuts a steep path through the plane of the planets. Right now the comet is well below the plane but is on its way “up”. On October 19, 2014, it will pass extremely close ot Mars. Credit: NASA/JPL

Although not expected to pass particularly close to Earth next year, the comet will have a very close brush with Mars. Leonid Elenin, Russian comet hunter and discoverer of the famed Comet C/2010 X1 Elenin, has examined C/2013 A1′s orbit and found there’s a small chance it could collide with the planet Mars on October 19 next year.

Based on 74 days of observations plus the latest data from Elenin, which admittedly only cover a short piece of the comet’s arc, A1 could zoom as close as 22,990 miles (37,000 km) from the surface of Mars and shine 40 times brighter than Venus at magnitude -8.5 … as seen from Mars that is. Earth observers will see it around 8th magnitude, so you’ll need a pair of binoculars at minimum.

Since a comet’s tenuous outer atmosphere – called a coma -  is typically around 62,000 miles (100,000 km) across, C’/2013 A1 is practically guaranteed to give the planet a gentle powdering.

Diagram showing how the orbit of the comet intersects the orbit of Mars on October 19, 2014. Credit: Leonid Elenin

Given the close brush, there’s even a possibility – for now – that it might crash right into the Red Planet.

This is where things get interesting. Astronomers estimate a comet’s size by measuring how its brightness changes during its approach to the sun. C/2013 A1 turns out to be a potentially BIG comet with a diameter estimated at up to 31 miles (50 km) across.

Its orbit is also tipped over so far (greater than 90 degrees to the plane of the solar system) A1 travels in retrograde motion opposite the direction in which the planets move around the sun. Should it aim for Mars, the two bodies will hit head-on with the comet speeding at 35 miles per second. Dare I say, the energy released from the impact would be prodigious.

Here’s Elenin’s take: “This kind of event can leave a crater 500 km (310 miles) across and 2 km (1.2 miles) deep. Such an event would overshadow even the famous bombardment of Jupiter by the disintegrated comet Shoemaker–Levy 9 in July 1994, which by some estimates was originally15 km (9 miles) in diameter.”

A blast that powerful would easily be visible from Earth as a brilliant flash of light followed by a massive cloud of debris expanding over the Martian landscape and high into the planet’s atmosphere. From Mars, the event could be photographed by one of several Mars-orbiting satellites or even the Curiosity rover. Even if the comet misses the planet, we’d hope NASA or ESA (European Space Agency) could point a camera to take the first-ever photos of a comet from another planet.

The view from mid-northern latitudes facing southwest on October 19, 2014 when the comet and Mars will be extremely close in the evening sky after dusk in Ophiuchus near the “Teapot” of Sagittarius. The path shows the comet’s position every five nights. Created with Chris Marriott’s SkyMap software

Could this all be crazy talk? Maybe. In order to make a firm prediction of exactly what path the comet is on, astronomers will accurately measure its position and refine its orbit in the coming months. Chances are, it won’t hit, but the possibility remains … for the moment.

As for Earth, we’re in the the clear. C/2013 A1 will miss us by 84 million miles even when closest in early September next year. If we assume for a moment that the impact will happen, sky watchers in the eastern hemisphere will have the best seats. I checked the the positions of comet and planet in SkyMap, a highly accurate planetarium program, and determined the time of closest approach to be around 5:30 a.m. Central Time Oct. 19, Mars won’t be up in the sky for the U.S. but will be for much of Russia, China and other eastern hemisphere countries. For observers there, a possible impact would occur during early evening hours on Oct. 20.

Mars will be in the constellation Ophiuchus at that time and low in the southwestern sky at the end of evening twilight. For observers in the U.S., Canada and South America, the planet and comet, should it survive, will be only about half a degree apart at dusk the evening of the 19th. Big blast or not, they’ll certainly make for a memorable sight in a telescope.

Comets Panstarrs and Lemmon share a Kodak moment

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Two for the price of one! Comet L4 PANSTARRS is bright dot lower left with a short tail; Comet F6 Lemmon and its skinny tail are visible at right next to the Small Magellanic Cloud, a satellite galaxy of the Milky Way. Click to enlarge. Photo taken on Feb. 17, 2013 from Australia. Credit: Justin Tilbrook

Justin Tilbrook of Australia took a marvelous image earlier this week showing our two current comet celebs F6 Lemmon and L4 PANSTARRS together in the same picture.It’s not often you’ll see two tail-toting comets captured with a wide-angle lens at the same time.

To bring you up to date, Panstarrs is still visible very low above the horizon in morning twilight from far southern latitudes. This week it’s brightened to 4th magnitude and appears like a fuzzy pearl with a short tail. One observer noted a yellow color to the comet’s head caused by dust reflecting the ever-intensifying sunlight as PANSTARRS barrels sunward toward its March 10 perihelion.

Comet Lemmon photographed on Feb. 20, 2013 through a 19.6 inch telescope. Click to enlarge Credit: Martin Mobberley

Lemmon is higher up in the sky but fainter at magnitude 5.5. Right now it might be difficult to see with the naked eye because of moonlight. Binoculars show a bright head and a  1/2-degree-long tail.

You might be interested in a recent study on brightness predictions for comets L4 PANSTARRS and ISON by Ignacio Ferrin of the University of Antioquia in Medellin, Colombia. Here are the main points:

* C/2011 L4 Panstarrs will be less bright than Halley’s Comet was in 1986. It will show
a tail easily detectable with the naked eye.

* There’s a 75% chance that  C/2012 S1 ISON will continue to brighten and put on a great show late this fall. Ferrin predicts it could become as bright as the full moon (magnitude -12.6) when nearest the sun. But his prediction comes with a caution: ISON will pass within the Roche Limit when it swings around the sun in late November. This is the minimum distance a smaller body can hold together in one piece while orbiting a larger body without being torn to bits by the larger body’s overwhelming gravity.

At top, an object like a comet has crossed the Roche Limit and starts to disintegrate into pieces. Below, the individual pieces spread out according to distance. Particles closer to the sun (left) move more quickly (red arrows) than those farther away. Credit: Wikipedia

Ferrin writes: “Any object within this limit  has a large probability of disintegrating due to differential gravitational forces from the Sun. The combinations of Roche’s Limit, plus solar radiation plus very high temperature, suggest that the comet may not survive its encounter with the Sun, disintegrating into several pieces. Or it may survive, if its internal cohesion is
sufficient to endure those conditions.”

If you’d like to learn more, please check out the complete study.

Mid-February bright comet update: Panstarrs, Lemmon, Bressi, Ison

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Comet Panstarrs on Feb. 8, 2013 photographed with a 300mm telephoto lens from Castlemaine, Victoria, Australia. Observers describe very bright head and broad tail. Click to see more comet photos. Credit: Michael Mattiazzo.

There are a lot of icy mudballs , ie. comets, flying around up there at the moment, so let’s take a look at what’s happening. We’ll start with C/2011 L4 PANSTARRS, better known as Comet Panstarrs. It’s been slowly brightening to within naked eye range, hovering now right on the edge of visibility under dark skies. Recent observations by amateur comet observers put the comet a smidge above the naked eye limit at magnitude 5.5-5.7. It’s a snap to see in binoculars in morning twilight in the southern hemisphere. As you can tell from the photo, it has an intensely bright, almost star-like head and wide, dusty tail that’s about 1/2 degree long. It should be a most excellent sight in binoculars for both northern and southern hemisphere sky watchers when it emerges at dusk in the western sky next month. We’re only four weeks away!

What a comet! This is Comet Lemmon shot through a 5-inch widefield telescope on Feb. 8, 2013 from Possum Observatory Complex in Gisborne, New Zealand. Click for large version. Credit: John Drummond

Meanwhile, another comet has temporarily stolen the show. C/2012 F6 Lemmon has swelled into a huge, green leek of a thing, Like Panstarrs, it too is faintly visible with the naked eye (mag. 5.8) under dark skies for southern hemisphere skywatchers. How come they get all the fun?

A long, thin exclamation point of a tail shoots from Lemmon’s giant, whipped-up coma or cometary atmosphere. Good news is, the comet is still brightening and may reach 3rd magnitude, making it an easy sight even from the suburbs.

We northerners will have to be patient if we want a glimpse of this comet. Not until early May, when it swings around the sun and enters the morning sky at about magnitude 5, will we get our chance.

You can see the fading of Comet Bressi in this sequence of photos made by Rob Kaufman of Bright, Victoria, Australia.

Then there’s C/2012 T5 Bressi, a modest, unassuming comet that experienced a bright outburst in late January. In a matter of days it became 10 times brighter than expected. On Feb. 4, Bressi glowed at 9.2 magnitude and then slid to 10.5 the very next day.

Sad to say, this is a bad omen for a comet and usually means the beginning of the end. They are crumbly things after all and subject to breakup as their ices volatilize under the relentless sun. Unfortunately, the nail might get hammered into Bressi’s coffin on Feb. 24, when it reaches perihelion or closest distance from the sun (28 million miles). Some comet observers predict it will disintegrate around that time.

Reversed (negaitve) image of Comet ISON on Feb. 3. At the time, the comet was 4 times Earth’s distance from the sun. Credit: Rolando Ligustri / CARA Project

Finally we come to this year’s best hope for a brilliant comet – C/2012 S1 ISON. It’s still slowly cruising through northern Gemini and beautifully placed for telescopic observation every clear night for observers in the northern hemisphere. Would that it were a tad brighter. You still need a 12-inch or larger telescope to see this 15th magnitude fuzzy blotch. I shouldn’t be so offhanded. Ison has developed a short tail of late, lending it enough character to whet our appetite for things to come.

By late fall, ISON should be an easy binocular object in the morning sky. Come Christmas it’s likely to be a glorious sight at dusk. Tag along with me and I’ll let you know how it goes as the clocks ticks cometward.

How to get the best views of Comet Panstarrs this March

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Comet C/2011 L4 PANSTARRS with its dusty tail photographed on January 27, 2013 from Australia, where it’s well placed for viewing before dawn. Taken with an 11-inch telescope. Credit: Michael Mattiazzo

Even if Comet L4 PANSTARRS doesn’t become the spectacle many of us hope it will be, it will almost certainly be visible with the naked eye and a fine sight in binoculars, with a sweeping tail pointing away from the sun.

The latest predictions by knowledgeable amateur comet observers peg it at between magnitude 2 and 3 when far enough from the glare of the sun to see. That compares well with the brightness of the stars in the Big Dipper. Not too shabby as comets go.

Comet PANSTARRS won’t make its first appearance for northern hemisphere skywatchers until the first week of March during evening twilight. That’s only 5 weeks from now. For the U.S. the comet will appear in the western sky very near the horizon. Observers in the southern states will have a slightly better view with the comet standing a degree or two higher through the 12th; after that all locations across the country will be equally blessed. If you want to see it from the start when the comet’s also brightest, you’ll need an observing spot with a view as far down to the western horizon as possible.

Look for an observing site with a wide view down to the horizon to ensure a good view of Comet L4 PANSTARRS. Photos: Bob King

Scout your neighborhood or take a drive away from home to a nearby soccer field, park or other place with an open view to the west. Once you’ve found your ideal location, go out on the next clear, moonless night and scan that direction for city light pollution. Unless you live in the countryside, a small amount of city glow is inevitable. That’s OK. Few places are light-pollution free these days.

But if your western sky is filled with a star-swamping, foggy miasma on what is otherwise a dark, clear night, consider putting another 10, 15 or 20 miles between you and your town for a better view. If you need help finding a good site or need additional expertise, contact your local astronomy club. Here’s a directory of clubs across the U.S.

Comet L4 PANSTARRS keeps low to the horizon when its brightest from early to mid-March. The map shows the comet’s position and approximate tail direction each night from March 7-25 about 30 minutes after sunset from the mid-section of the U.S. (around latitude 42 degrees N). Created with Chris Marriott’s SkyMap software

Because of L4 PANSTARRS’s low altitude during the first half of March, light pollution, natural horizon haze and twilight itself will compromise the view. From first appearance near the sun in the west-southwest around March 7, the comet never gets higher than about 10 degrees (one fist held at arm’s length) between March 8-20, the time during which it’s expected to put on the best show. While the bright head of the comet will still be visible, much of its tail could well be masked by city light or haze. A dark site is best.

Later, as the comet moves northward and higher, it will fade but may become easier to see as it moves into a dark sky. Binoculars should show it through early May and perhaps even later. From mid-May onward, L4 PANSTARRS becomes circumpolar for observers at mid-northern latitudes and remains visible all night long. At that time it will shine around 8th magnitude and require a small to medium-sized telescope to view.

Comet L4 PANSTARRS reaches perihelion (closest to the sun) on March 10 at a distance of 27.9 million miles or about 6 million miles closer to the sun than Mercury is on average. Intense solar heating will cause the comet to grow a fine dust tail that could stretch for many degrees away from the sun. Closest approach to Earth happens on March 5 at 102.3 million miles – hardly a close shave but good enough for a nice show.

8×40 (left) and 10×50 binoculars are excellent for bright comet viewing. You can pick up a decent pair for around $50-100. Photo: Bob King

As far as the best instrument to use, we’re all hoping PANSTARRS will be bright enough to see plainly with the naked eye. Based on its predicted brightness and tail development, a binoculars will probably provide the best view.

Get a pair that magnify between 7x and 10x with an aperture (lens diameter) of 40 to 60mm. 10×40, 10×50 and 7×50 models are perfect, and they’re reasonably priced, too. Avoid binoculars that magnify 20x or 30x. While more power sounds tempting, anything above 10x will narrow the field of view and make the binoculars nearly impossible to hold steady.

My favorites are the 10×50 wide field variety with lots of eye relief. Large eye relief lets us unfortunates who must wear glasses see the entire field of view instead of getting the equivalent of looking through a straw.

Uwe Pilz of Germany wrote a program that follows the path of dust particles in comets and created these excellent simulations of PANSTARRS’ dust tail. The aqua blue line points away from the sun; the black line is 0.9 degrees long so you estimate tail length. Click image to see the larger complete set. Credit: Uwe Pilz

Comet PANSTARRS is what astronomers term a dynamically new object, making its first visit to the inner solar system after millions of years in the deep cold of the comet repository known as the Oort Cloud. Such comets make a bright appearance at great distance because their rarefied ices are ripe to vaporize. This can lead one to think that the comet will continue to brighten into negative magnitudes as it approaches the sun and Earth. But after those virgin ices have sublimed away, new comets often settle down and lag behind predictions. The old hats who’ve been around the block a few times brighten and fade more reliably.

Whatever happens with PANSTARRS is worth watching. As we’ve encountered with previous comets, unpredictability is their charm. The comet could be brighter, fainter, experience a sudden outburst of brightness or disintegrate into clods of dust. I hope we’re all fortunate enough to witness such revelatory moments in nature.