Morning aurora topped off by avian cheer

A pretty series of rays sprouts above a pair of green arcs this morning around 3 a.m. CDT. Photo: Bob King

I got up for the stars but stayed for the birds. Clear skies overnight allowed for a look at a surprise aurora display, comets PANSTARRS and Lemmon, a handful of spectacular Eta Aquarid meteors and an attractive lunar crescent early this morning.

Three images from NASA’s Solar Dynamics Observatory were combined to create this spectacular view of last Friday’s flare. Credit: NASA

No auroras were predicted and true-to-forecast all looked quite at least through midnight. But at 2:30 this morning a bright green band spanned the northern horizon punctuated by one, two and occasionally an entire series of faint, rosy rays.

Sunspot group 1734′s largest spot – at left – is several times the diameter of Earth. This photo was taken this morning May 6, 2013. Credit: NASA

Expect more excitement courtesy of our parent star. Last Friday, a big flare erupted along’s the sun’s eastern edge, hurling a dragon-like tongue of incandescent hydrogen gas 120,000 miles (193,000 km) above the surface. Although this storm wasn’t directed toward Earth, the large sunspot group 1734 is currently nearly face-on to the planet and has the potential for strong flares. Cross your fingers.

A bright Eta Aquarid streaks across the northern sky and aurora this morning around 2:45 a.m. Photo: Bob King

I had planned to look at a variety of objects in the telescope but kept getting “distracted” by both the northern lights and regular appearances of incredibly fast, long-trailed meteors streaking across the northern sky from the east – Eta Aquarids.

Because the shower has a broad peak I encourage you to go out for a look yourself. Being so far north, I figured only a few might be seen here in Duluth, Minn. but was happily proven wrong. Had I simply sat in a lawn chair and stared skyward I’m certain I would have seen many more. Click HERE for more on the shower and how to view it.

A wide-field photo of Comet C/2011 L4 PANSTARRS shot on May 4, 2013. The comet is oriented the way it would appear shortly before dawn with the anti-tail pointing down and broad dust fan opening to the left. Credit: Joseph Brimacombe

Let me tell you about Comet PANSTARRS. In 10×50 binoculars I was surprised by how much there was to see under a dark sky. The V or fan-shaped tail spread is still obvious marked at its base by the small, brighter comet’s head. A second, straight anti-tail (debris left by the comet along its orbital path) stuck out like a pinkie finger from one side.

I estimated the whole works measured 1 degree or two full moon diameters across. While faint and smoky-looking at magnitude 7, the comet was very easy to pick out. In a 15-inch telescope PANSTARRS and its dual tails were brighter and better-defined; a tiny star-like nucleus peeped through the gases and dust concentrated in the its head. Very beautiful.

A morning topped off by the crescent moon is never wasted. Photo: Bob King

On to Comet Lemmon. I didn’t see it until 4 a.m. when dawn’s first light had already put its pale stamp on the eastern sky. I found it with difficulty in binoculars as a small, dim soft patch of light below the lower left star in the Square of Pegasus VERY low in the northeastern sky. It’s about as bright as PANSTARRS but low altitude and the onset of twilight combined to make it look fainter. In the scope, Lemmon was a big pale green fuzzball with a hint of a tail pointing southwest. Care to find it yourself? Here’s a map.

Wherever you are, enjoy the coming nights. If the moon’s your thing, an even thinner crescent will rise an hour before sunrise tomorrow in the east. Check for northern lights before you turn in tonight and use the map from yesterday’s blog to try your luck at Comet PANSTARRS … one last time.

 

Listen to the Chelyabinsk fireball’s infrasound tsunami

 

Click image to see and hear multiple explosions of the fireball when it broke apart 12-15 miles high over Chelyabinsk, Russia on Feb. 15, 2013. This video scares me every time I see it.

You’ve probably seen and heard at least one video of February’s fireball exploding over Cheylabinsk, Russia. The shock wave from entry and subsequent break up of the meteoroid blew out thousands of windows, caused part of a building to collapse and set off countless car alarms.

A tiny sampling of the thousands of pea-sized meteorites recovered from the Chelyabinsk region after the fireball. Credit: Mike Farmer

Scientists estimate the incoming object measured about 55 feet (17m) across – as big as a 5-story building – weighed 7,000 tons and blazed across the sky at over 40,000 mph (64,000 kph). The shock pressure and heat upon entry converted much of the mass into dust, seen as a smoky “contrail”, and the rest into thousands of small meteorites that pocked snow drifts in the surrounding countryside.

Click image to listen to the atmospheric “tsunami” that sent waves of infrasound around the globe.

While the Chelyabinsk event was the most impressive witnessed meteor in more than 100 years, its effects were even more far-reaching. Almost 6,000 miles (9,600 km) away in Lilburn, Georgia a full 10 hours after the explosion, infrasound sensors recorded multiple rumbles from the object’s impact with the air.

Infrasound, a very low frequency sound wave that can travel long distances, can’t be heard by human ears but can be detected with sensors. When a large meteor enters the atmosphere it sends ripples of infrasound through the atmosphere and around the planet revealing information about its speed, direction of travel and how much energy it contains.

Locations of the Earthscope’s seismic sensors across the U.S. and into Canada. Click map and see if one is near you. Credit: National Science Foundation / Earthscope

Lilburn is home to one of nearly 400 seismic/infrasound stations in use in the eastern United States. They are part of a large-scale project named Earthscope, an initiative funded by the National Science Foundation that studies the Earth’s interior beneath North America. Although the stations mostly record seismic waves from earthquakes, they also are sensitive to long-period waves of infrasound.

Georgia Tech faculty member Zhigang Peng took the Lilburn infrasound data, sped it up and amplified it so we can heard the reverberations created by the falling meteoroid as it plowed through the atmosphere.

Click image to hear infrasound recording of a North Korean nuclear test and a magnitude 5.1 Nevada earthquake by Peng

“The sound started at about 10 hours after the explosion and lasted for another 10 hours in Georgia,” said Peng. Like a tsunami set in motion by an earthquake, the Chelyabinsk meteoroid created a series of tsunami-like waves in the atmosphere itself. Both travel at nearly the same speed.

Peng has used the same process to convert seismic waves and underground nuclear explosions into audible sound. Click above for a listen. Check out this site for more exploding Chelyabinsk videos.

Sweeten your May mornings with Comet Lemmon

Comet C/2012 F6 Lemmon cruises up the side of the familiar Great Square of Pegasus this month. Look for it starting about 90 minutes before sunrise low in the eastern sky. Let the W of Cassiopeia point you toward Alpha Andromedae; from there you can star-hop to the comet using binoculars. Stellarium

Looks like Comet PANSTARRS has company.This week Comet Lemmon begins nudging its way into the early dawn sky. Watch it to slowly climb up the eastern side of the Great Square of Pegasus in the coming weeks. Both comets are now below the naked eye limit and glow around 7th magnitude.

A beautiful pairing of Comet PANSTARRS and two bright nebulae – NGC 7822 (top) and Cederblad 214 (center) – in the constellation Cepheus on April 30. The colors of the comet and nebula are strikingly different. Sunlight reflected by dust colors the comet’s tail yellow; the light of hot, young stars embedded within the nebulae causes hydrogen gas to fluoresce red. Credit: Michael Jaeger

From a dark sky 7×50 and 10×50 binoculars will easily show Lemmon as a fuzzy spot, and you might even spot a long, thin tail. The comet slowly fades during the month while rising higher and becoming easier to see in the morning sky. You can use the map here to help guide you to it; for more details, check out this recent article I wrote that appeared in Universe Today.

Aurora update April 13-14 – nothing yet, but …

Cassiopeia, Comet PANSTARRS and a bit of aurora tonight from Duluth, Minn. around 10:15 p.m. Details: 35mm lens at f/2.8, ISO 1600, 30-second exposure. Photo: Bob King

Just got back from a quick look north. Comet PANSTARRS shone dimly but clearly in 10×50 binoculars in the W of Cassiopeia in the northwestern sky. I could easily see the brighter head and its short, diffuse tail about 1 1/2 degrees long (equal to 3 full moons side by side). The comet’s looks ghostly now compared to its glory days, but its basic form remains much the same.

Magnetic activity around the Earth kicked up a little earlier this evening before sunset in the eastern U.S. but has since fallen back. Judging by the satellite maps, it didn’t look like anyone watching from mid-northern latitudes would have seen an aurora. In the photo above, the camera recorded a minor blush of red and green aurora that barely cleared the northern horizon.

Things are quiet for the moment but that could change. There’s still a 45% chance of a minor auroral storm (15% chance of a major storm) overnight for middle latitudes like Wisconsin, Minnesota, Michigan and the like. Let’s hope it happens. If not, we’ll keep our chins up for the next one.

Comet ISON dallies on path to greatness

Comet C/2012 S1 ISON with its tadpole-like tale photographed through a 14-inch telescope on April 1. The comet has brightened little in the past three months. Credit: William Wiethoff

So what’s up with Comet ISON? I first saw it in a telescope on Jan. 7 as a barely visible bit of fluff. Guess what? It still is.

Remember, this is the comet that’s predicted to grow as bright or brighter than Venus come November when it will pass just 600,000 miles from sun. You’d think by now it would be brighter than back in January. But comets almost always have surprises up their sleeves, and ISON is no exception.

If it holds together during its extremely close swing around the sun on Nov. 28 this year, Comet ISON should become much brighter and display a longer tail than Comet PANSTARRS did this spring. The illustration shows the comet’s visibility in two of the Solar and Heliospheric Observatory’s cameras (red is close up) at that time. Credit: NASA

Three nights ago I struggled again to find it on a very dark night using the same telescope and magnification. Once again, I saw only smallest fuzzball shining at a very meek 15th magnitude. In a word, the comet had changed little in nearly 3 months (Jan. 7 – April 5). Amateur astronomers measuring ISON’s brightness from photographs confirm the lag.

A tailless Comet ISON on Jan. 4 this year. Credit: Artyom Novichonok

Let’s look at the particulars using a distance measure called the astronomical unit or A.U. One A.U. is equal to the span between Earth and sun or 93 million miles.

On Jan. 7, the comet stood 4.21 A.U.s from Earth and 5.2 A.U.s miles from the sun. This week it’s nearly the same distance from Earth – 4.22 A.U.s – but significantly closer to the sun at 4.2 A.U.s. That’s 93 million miles closer to the sun now than in January, yet in spite of the increased heat it’s now receiving from the sun, ISON has remained at nearly the same brightness and size. Some amateur astronomers have reported that it’s even shrunk a bit. One encouraging sign however – the comet’s grown a short tail over the winter months.


Short animation of Comet ISON’s trek around the sun through May 2014

Comet ISON is likely making its first trip to the inner solar system ever, coming to us from the remote Oort Cloud, a refrigerated “storage locker” of trillions of comets gathered into a thick spherical halo at the fringes of the solar system. The near edge of the Cloud is some 5,000 A.U.s from the sun or 465 billion miles away (Pluto is “only” 3.6 billion miles away) and it extends outward perhaps as far as 9.3 trillion miles or more than a 1/4 the way to Alpha Centauri, the nearest star beyond the sun.

Artist’s conception of the Oort Cloud and Kuiper Belt, the two places from which comets originate. PANSTARRS and ISON hail from the Oort, a huge spherical shell extending to the edge of the solar system. Credit: NASA

Far from the sun, an icy comet’s temperature hovers around absolute zero (-459 F). If you could see it up close, there would be no fuzzy coma or tail just an inert hunk of dark ice.

The sun turns a comet on when it’s somewhere between 280 to 465 million miles away. By that I mean that the coldest of its ices – nitrogen, carbon dioxide and carbon monoxide – begin to thaw and vaporize, forming a gassy shroud around the icy nucleus called a coma.

Because outer space has no atmospheric pressure, ice goes directly from solid to vapor with no liquid in between. This is what we see happening with Comet ISON right now.

Comet ISON passes through Gemini, Cancer and Leo as it falls toward the sun. Credit: NASA’s Goddard Space Flight Center/Axel Mellinger

Observations made on Jan. 30 by NASA’s Swift space probe measured how much material the comet was losing due to solar heating: 112,000 lbs. (51,000 kg) of dust and 130 lbs. (60 kg) of water per minute. The water amount is much lower because ISON is still so far from the sun. Based on these rates, scientists estimate the comet’s diameter at 3 miles (5 km), which is typical for these objects.

What’s curious however is that ISON has barely if at all brightened in 3 months. Maybe the comet’s unusually small or has already lost its coating of easily-vaporized exotic ices. Or maybe it’s just being a comet with all the unpredictability that implies.

If it survives its close pass to the sun, ISON should put on a great show in late Nov. and December in both evening and morning skies. It passes closest to Earth on Dec. 26. Created with Christ Marriott’s SkyMap program

Lest you be too concerned that ISON won’t perform to expectations, we’ll get a much better idea of where it’s headed brightness-wise when it moves to within 1.5-3 A.U.s or between Mars and the inner asteroid belt. Here solar radiation is intense enough to vaporize its abundant water ice which and give the comet a major “lift”. Expect that to happen sometime in July and continue through the fall.

Comet PANSTARRS served as the warm-up act to what we hope will be the year’s main venue. The grain of salt we tasted in hunting down that comet will not only temper expectations for ISON but help us appreciate the unique character of each. Like snowflakes, no two comets are alike.

As we drive off to work or school, Comet ISON continues its sunward trek across the constellation Auriga, now high in the northwestern sky at nightfall. Like the comet, we may start our day with certain expectations, but an unanticipated turn of events can sometimes lead to a different outcome at day’s end. Down here on Earth we call that life.

Comet PANSTARRS x 2 and the Pan-STARRS asteroid survey

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!

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

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.

Comets Panstarrs and Lemmon share a Kodak moment

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

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.

Best astronomy events of 2013 – a look into the crystal ball

What’s in the stars for 2013? Check out the list below. This picture is of the star-forming region NGC 3603 photographed with the Hubble Space Telescope. Credit: NASA/ESA

With 2012 under our belt, we look forward to what the new year will bring. It’s a big, wild sky up there. Below you’ll find a month-by-month listing of some of the highlights. 2013 could go down in history as the year of spectacular comets. Both C/2011 L4 PANSTARRS and C/2012 ISON are expected to become at least as bright as the brightest stars. Comets are unpredictable however, so we’ll have to wait and see. No problem. That’s what we lovers of the sky do best.

JANUARY

* Jan. 3 – Peak of the annual Quadrantid meteor shower during the early morning hours when up to 80 meteors per hour could be seen. A waning gibbous moon will compromise the view and the peak is a very short sliver of time. Observers in Asia are favored.

* Jan. 21 – The waxing gibbous moon has a very close conjunction with the planet Jupiter in the evening sky. They’ll be about one moon diameter apart.

FEBRUARY

Path of asteroid 2012 DA14 during its February flyby. The green circle is the ring of geosynchronous satellites in orbit around Earth. Credit: NASA/JPL

* Feb. 7 and 8 – Mercury passes very close to Mars (0.3 degrees) low in the western sky at dusk

Feb. 15 - Asteroid 2012 DA14 zooms just 21,000 miles from Earth around 2 p.m. (CST) this afternoon. The 147-foot long boulder will not impact the planet and the chances of it striking a satellite in the geosynchronous belt is near zero. At brightest it will shine at magnitude 7.7.

* Feb. 16 – Mercury at greatest elongation east of the sun and easy to find during evening twilight.

* Feb. 28 – Late tonight the moon will pass just 1/10 of one degree south of Virgo’s brightest star Spica – that’s close!

MARCH

A modest comet on September 9, 2012, C/2011 L4 PANSTARRS is expected to become a fine naked-eye sight in March. Credit: Michael Mattiazzo

* March 8-20 – Comet C/2011 L4 PANSTARRS emerges in the western sky after sunset with a brilliant head and ever-lengthening tail. Its height increases night by night as the comet fades. Expected magnitude of around 0 or about as bright as the star Vega. A much anticipated event! The thin lunar crescent passes close to the comet on the 12th.

* March 20 – First day of spring for the northern hemisphere begins at 6:02 a.m.

APRIL

* April 24 – Another extremely close approach of the waxing gibbous moon and star Spica

* April 25 – Partial eclipse of the moon. Visible from Australia, Asia, Europe and Africa but not from North or South America.

April and May are the best times to view Saturn and its beautiful rings through a telescope. Credit: Damian Peach

* April 28 – Opposition of Saturn when it’s closest and brightest for the year. The planet shines at 0.1 magnitude in Libra and rises at sunset. The rings are nicely open to view and can be seen in any telescope magnifying at least 30x.

MAY

* May 5-6 – Peak of the Eta Aquarid meteor shower. This is modest shower with a rate of about 10-15 per hour radiating from the constellation Aquarius. Best viewed in the early morning hours. Moonlight from the setting waxing gibbous moon will comprise the shower somewhat.

* May 9Annular eclipse of the sun. Not visible from North America but will be partial in Hawaii. Path of annularity passes through northern Australia and the tip of New Guinea.

Attractive planet grouping low in the northwestern sky during early twilight on May 26, 2013. Created with Stellarium

* May 22-30 - Venus, Mercury and Jupiter cluster together low in the western sky after sunset. Close conjunctions of Venus and Mercury (24th), Mercury and Jupiter (26th) and Venus and Jupiter (27th-28th). Low but a potentially great show. The southern states will have the better views.

* May 24-25 – Penumbral lunar eclipse visible across North America except Alaska. Keen-eyed observers might notice some shading along one side of the moon as it dips into Earth’s outer shadow called the penumbra. Eclipse starts at 10:43 p.m. CDT and ends at 11:37 p.m. May 24.

JUNE

* June 1 – Striking lineup of Jupiter, Venus and Mercury low in the western sky after sunset. Find an unobstructed horizon to see best.

* First week of June – Mercury well-placed for viewing low in the western evening sky.

* June 21 – First day of summer in the northern hemisphere begins at 12:04 a.m. CST.

JULY

* July 3-4 – Venus returns to the evening sky visible low in the west during twilight. On these dates, binocular users will see the planet pass in front of the Beehive star cluster in Cancer.

* July 21-23 – Conjunction of Mars and Jupiter. Both planets now return to the morning sky and pair up within one degree of each other on these dates. They’re visible in Gemini low in the eastern sky before sunrise.

* July 28-29 – Peak of the Southern Delta Aquarid meteor shower. Up to 20 meteors per hour before dawn radiate from the constellation Aquarius. Compromised this year by the waning gibbous moon.

AUGUST

Perseid meteor. Credit: Kohle Kredner

* August 3-5 – Very nice lineup of Mercury, Mars and Jupiter joined by the thin crescent moon these mornings. Look to the east about an hour before sunrise.

* Aug. 12-13 – Peak of the great Perseid meteor shower. Up to 80-100 meteors per hour are visible especially after midnight. This year the moon is a thick crescent that sets before 11 p.m. and won’t compromise the shower.

* Mid-August – Comet ISON emerges into the dawn sky in the constellation Cancer shining around 11th magnitude, bright enough to spot in amateur telescopes.

SEPTEMBER

* September 5-6 – Venus near Spica low in the southwestern sky at dusk

* September 8 – Fine conjunction of the crescent moon and Venus this evening

* September 19 – Full Harvest Moon

* September 22 – Fall starts with the autumnal equinox at 3:44 p.m. CDT.

OCTOBER

* Maximum of Sunspot Cycle 24 predicted to happen this fall. It appears this will be the smallest cycle since Feb. 1906.

During a penumbral lunar eclipse, like this one in 1999, one edge of the moon is slightly shaded. To the eye, it appears blunted.

* October 18 – Penumbral eclipse of the moon partially visible from North America. The moon enters Earth’s outer shadow (penumbra) at 4:48 p.m. CDT and exits at 8:52 p.m. The shading should be more noticeable than during May’s penumbral eclipse.

* October 21 – Peak of the Orionid meteor shower which originates from dust trailing Halley’s Comet. About 20 meteors per hour radiate from the constellation Orion after midnight. Meteor counts will be reduced due to light from the waning gibbous moon.

* Late October – Comet ISON brightens to magnitude 7 and becomes visible in binoculars

NOVEMBER

* November 1 – Venus at greatest elongation east of the sun. It finally gains some altitude and becomes much easier to see this month during evening twilight.

* November 3 – The only total solar eclipse this year. Visible across the equatorial Atlantic Ocean and West Africa. Not visible in North America.

* Early November – Comet ISON should be visible with the naked eye at 2nd magnitude (as bright as the Big Dipper stars) in the morning sky.

* November 17-18 – Peak of the annual Leonid meteor shower. 10-15 meteors per hour are expected but the full moon will make a big dent in meteor counts.

* November 25-26 – Mercury and returning Saturn meet up together for a close conjunction. The two will be just one degree apart on these dates.

* November 28 – Perihelion of Comet ISON. This is when the comet will be closest to the sun. It’s expected to shine brighter than Venus and visible near the sun in the daytime sky with proper viewing precautions. The comet will look like a star with a short tail.

DECEMBER

It doesn’t look like much in this photo taken on Dec. 9, 2012, but astronomers predict that Comet ISON could become a bright naked eye comet this month. Credit: Rolando Ligustri

* Early thru mid-December – Comet ISON at its best. Visible in both the early morning and evening skies, ISON hurries northward away from the sun’s glow. It’s expected to be nearly as bright as Jupiter with a long tail.

* December 6 – Venus dazzles as it climbs higher and reaches greatest brilliancy for the year.

* December 13 – Peak of the great Geminid meteor shower. About 100 meteors per hour are visible from a dark sky, but this year the waxing gibbous moon will compromise the view until after moonset around 4 a.m.

* December 21 – Winter begins with the solstice at 11:11 p.m.