Rosetta’s comet shows off new bumps, bruises and bright collar

New views of Comet 67P/C-G show more surface features including a bright collar. The dark band in the middle and right images is the shadow cast by one part of the comet on its other half during rotation. Each picture is separated by 2 hours. Credit: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA

Pictures taken July 20 of comet 67P/Churyumov-Gerasimenko by the Rosetta spacecraft show cool new stuff. They include several tantalizing depressions in both lobes of the comet and a bright collar where the two dissimilar halves meet.

3-D model of the comet’s shape based on July 14 images. Credits:ESA/Rosetta/MPS for OSIRIS Team MPS

What makes the comet’s ‘neck’ bright might help us understand how 67P/C-G got its strange shape. It could be a region of freshly exposed ice, differences in the composition of the material where the two lobes meet or a change in elevation in the landscape. More detailed studies including examination with a spectrograph to nail down its composition will have to wait until August 6th and beyond, when Rosetta parks itself in orbit.

Look closely and you’ll also see several depressions. One of the largest is a shallow bowl at the top of the smaller lobe. No one knows if these are impact craters or some kind of collapse pits created where ice below the surface vaporized away during the comet’s regular swings past the sun every 6.5 years.

More and more observations of the 67P/C-G are being made every day. Everything from determining its mass and volume, which will be used to arrive at the comet’s density, to measuring the rate at which gas and dust boils off the icy nucleus.

The animation above covers one full 12.4 hour rotation of the nucleus. The next batch of pictures is expected on July 31 with the first high resolution images arriving on August 6.


Let’s face it, comets are just weird

Comet 67P/C-G photographed from a distance of about 7,500 miles (12,000 km) on July 14 the European Space Agency’s Rosetta spacecraft. Credits: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA

Mesmerizing. The recent video of Comet 67P/Churyumov-Gerasimenko tumbling end over end looks like a boot booted into space. 36 images were used to create the brief time lapse which makes it look like as if the comet’s spinning rapidly. Its actual rotation period is 12.4 hours. Still, the extremely irregular shape of the 67P/C-G poses new challenges for the Rosetta team as they contemplate how to safely set down the Philae lander on such an irregularly shaped body come November 11.

Questions abound on how 67P/C-G got its peculiar shape. Most familiar solar system bodies like the planets and many of their moons are spherical or nearly so. Gravity’s the sculptor here. If an object’s about 240 miles (385 km) or larger in diameter, self-gravity will pull everything to the center and collapse the body into a sphere. Small objects like comets and most asteroids just don’t have enough material to ‘go spherical’. Comet 67P/C-G is only a few miles across, so it’s free to assume a variety of shapes.

These are all the comets we’ve seen up close so far by sending spacecraft there. All are small and most non-spherical. Credit: NASA/ESA

This all reminds me of a famous anecdote about Fritz Zwicky, a brilliant but prickly Swiss astronomer who worked most of his life at Caltech. He pioneered the use of supernovae as ‘yardsticks’ to measure distances to faraway galaxies and was the first to propose the existence of dark matter. Zwicky didn’t get along with everyone at Mt. Wilson Observatory, calling the astronomers there “Spherical bastards”. Why? “Because they’re bastards no matter how you look at them.”

Comet 8P/Tuttle, believed to be a contact binary, imaged by Arecibo radar Dec. 29, 2007-Jan. 5, 2008. Credit: Arecibo Observatory

ANYWAY … comets, being small icy bodies, come in a great variety of shapes from round to bowling pins to rubber duckies. Many ideas have been tossed around as to how 67P looks the way it does. I haven’t taken a poll but would suspect many astronomers would consider the comet a contact binary, two separate comets on convergent paths moving slowly enough that they melded together into one larger object.

Comet 67P/C-G and the Rosetta spacecraft to scale. The comet is about 4 km (2.5 miles) across. Credit: ESA

We also see contact binaries among the asteroids, but ice makes comets unique. Heat from the sun vaporizes that ice and carves away at the comet’s surface. Could eons of solar heating have shaped Churyumov-Gerasimenko? Comets are also fragile compared to most asteroids; some even crumble apart as they near the sun. It’s possible that vaporization of subsurface ices left parts of 67P in a weakened state which then crumbled away to sculpt its peculiar outline. Other possibilities include a near-catastrophic impact or gravitational stretching  during close encounters with Jupiter or Saturn.

Starting August 6 when Rosetta enters orbit around 67P, scientists will have more than a year to study it up close. Perhaps then we’ll get some more answers on its shapely origins. For instance, if we discover that each lobe of 67P has a different density or composition, the contact binary explanation would make a good fit. For now, let’s just say that comets’ weird shapes make them even more lovable.

What the? Rosetta’s comet is two comets in one!

Check this out! Rosetta’s comet is a contact binary, made of two separate comets that approached one another slowly enough sometime in the past to stick together as one. Click to enlarge. Credit: ESA /Rosetta /MPS for OSIRIS Team MPS /UPD /LAM /IAA /SSO /INTA / UPM /DASP /IDA

This just in. Comet Churyumov-Geramsimenko, the comet the Rosetta probe’s been chasing for the past 10 years, is really a double, what astronomers call a contact binary. Sometime in the past, two comets – possibly leftovers from the breakup of one larger object – approached one another at an estimated speed of 10 feet per second (3 meters/second) and stuck together to make the current day comet with a diameter of 2.5 x 2.2 miles (4 x 3.5 km).

A tighter crop on the comet shows its wild shape. Can’t wait for the closeups! Credit: ESA /Rosetta /MPS for OSIRIS Team MPS /UPD /LAM /IAA /SSO /INTA / UPM /DASP /IDA

Planetary Society blogger Emily Lakdawalla writes that the comet’s dual form could present some difficulties for the Philae lander, set to drop down on the comet’s surface this November 11:

“Philae navigator Eric Jurado as saying that “navigation around such a body should not be much more complex than around a nucleus of irregular spherical type, but landing the Philae probe however, could be more difficult, as this form restricts potential landing zones.”

I think the images are simply amazing and couldn’t wait to share them. Wow!

Rosetta spies a spinning comet!

Comet 67P/Churyumov-Geasimenko rotating on 27-28 June 2014. If you look closely, you can see the comet’s not quite spherical. Credits: ESA/Rosetta/MPS for OSIRIS Team

Look at that baby spin. Comet 67P/Churyumov-Gerasimenko covers only 4 pixels in this movie but you can see a shape emerging even at this level of resolution. The ‘era of the blip’ is over!

In this smaller version of the video, you can see the comet’s rotation and shape more clearly. Credit: ESA

The movie’s composited from 36 still images taken on June 27-28 from a distance of 53,438 miles (86,000 km) and shows the comet nucleus spinning at the rate of once every 12.4 hours. Yesterday the Rosetta spacecraft pulled to within 26,718 miles (43,000 km) of 67P; by Sunday it will be as far from the comet as you and I are from the geostationary belt of Earth-orbiting satellites – a mere 22,370 miles.

Comet 67P/C-G appears rather fuzzy in the movie and seems to cover a larger area just two by two pixels. This is due to the physical effects of the way light is spread inside the imaging system and is not associated with the comet displaying a coma. The effect will disappear in the next two weeks when the images swell to 20 by 20 pixels and larger.

Go, Rosetta, go!

Rosetta burns its way to a sweaty comet … 45,000 miles and closing

Rosetta’s target comet, 67P/Churyumov–Gerasimenko, is about 2.5 miles wide. Here it is shown alongside some of Earth’s landmarks. Credit: ESA

Boy, that was a good burn! No, I didn’t just down an ice-cold Coke too fast. That would be an engineer in the control room at the European Space Agency reacting to good news from the Rosetta comet probe.

On May 7, Rosetta began a series of ten orbital correction maneuvers (OCMs) designed to reduce its speed with respect to comet 67P/C-G by about 1,700 mph (775 m/s). The first, producing just 45 mph (20 m/s) ‘delta-v’ (change in velocity), was done as a small test burn, as it was the first use of the spacecraft’s propulsion system after waking from hibernation on January 20.

This graphic shows where Rosetta and the comet are in relation to each other and the inner solar system planets on July 2, 2014. Rosetta and its target are currently separated by fewer than 200,000 miles – less than the distance of the moon from Earth. Click to see where Rosetta will be in the future. Credit: ESA

Three big burns followed every two weeks starting May 2. The first four burns have slowed the spacecraft 86% toward its goal of ‘one meter per second’ or 2.2 mph, the speed needed to meet and enter orbit around the comet on August 6. That’s about the same speed as a leisurely stroll for you and I.

The next four burns are designated as the ‘Far Approach Trajectory’ (FAT) maneuvers, the first of which gets underway July 2 at 7:06 a.m. CDT. Mission controllers will fire Rosetta’s engine for a little more than an hour and a half to slow it down another 131 mph relative to the comet. After two additional burns later in the month followed by two final close-approach maneuvers, Rosetta will be ready to orbit the comet.

Although the spacecraft is now closer to comet 67P C-G than ever, I’m surprised no new images have been posted. The two are separated by fewer than 45,000 miles (72,000 km) on Monday or less than one-fifth the distance to the moon. It’s not easy being patient when you have eyes so close to the target. Any day now, any day now.

Not that Rosetta hasn’t been busy. On June 6, when it aimed a microwave sensor at 67P/C-G, it found the comet was losing about 10.5 fluid ounces of water in the form of vapor every second even though it was still halfway between Mars and Jupiter 364 million miles (583 million km) from the sun.

Comets, often referred to as ‘dirty iceballs’, are comprised of a mix of dust and several different types of ice with water ice being the most common. Heat from the sun vaporizes the ice, releasing dust and gases that form the fuzzy head and tail that give comets their distinctive character.

Even when still about half way between Jupiter and Mars comet 67P/Churyumov–Gerasimenko is losing the equivalent of two 10.5-ounce glasses (two larger coffee mugs) of water a second.  Click to read more about water detection in 67P. Credit: ESA

“We always knew we would see water vapor outgassing from the comet, but we were surprised at how early we detected it,” said Sam Gulkis of NASA’s Jet Propulsion Laboratory, who is in charge of Rosetta’s MIRO microwave instrument.

“At this production rate, comet 67P/Churyumov-Gerasimenko would fill an Olympic-size swimming pool in about 100 days,” he added. You think that’s a lot? The comet has only started to cook. Expect much higher rates of water fizzing into space in the coming weeks and months as 67P draws ever closer to the sun.

Zzzzzz … Rosetta’s comet takes a nap

Unlike the images of comet 67P/Churyumov-Gerasimenko obtained on April 30 (right), on June 4th no signs of an extended dust coma are evident. At that time,  267,000 miles separated Rosetta from its destination. Credit: ESA/Rosetta/MPS for OSIRIS Team

Comets are always full of surprises. That’s why we love them so. Take 67P/Churyumov-Gerasimenko, better known as Rosetta’s comet. Back on April 30, the Rosetta spacecraft saw a very active comet with a coma of dust and gas measuring 800 miles across. Even at 4 times the Earth-sun distance, solar heating had begun to vaporize comet ice.

But by June 4, when 67P was 18.6 million miles closer to the sun, activity appears to have shut down. Without its fuzzy coma, the comet looks like one of the many stars in the photo above.

Artist’s impression of the Philae lander expected to touch down on 67P/Churyumov-Gerasimenko this November. A comet’s core or nucleus is typically as dark as charcoal and only a few miles across. Sunlight reflecting off the dust and gas in their much larger comas and tails makes them appear bright . Credit: ESA

“67P is now almost within our reach – and teaching us to expect the unexpected,” said OSIRIS Principal Investigator Holger Sierks. “After 67P’s onset of activity, our images are currently showing a comet at rest,” he added. OSIRIS is the imaging system Rosetta uses to take photos of its target.

Jets flare in this illustration of 81P/Wild. Material from the jets goes into forming the comet’s dust envelope or coma. Sunlight pushes back coma gases and dust to form the comet’s tail. Credit: NASA

As the sun heats the icy nucleus, cracks develop and expose fresh ice and pockets of trapped gas to the vacuum of outer space. These rapidly vaporize and spew dust and gas like rocket thrusters. Astronomers call them ‘jets’. Jets can turn on and off and new jets can develop as the comet approaches the sun and then returns to deep space. That’s why it’s no surprise to see 67P take a temporary nap.

Usually, once a comet is within Mars distance of the sun, it remains active with an expanding coma and ever growing tail. We have much to look forward to. Currently, Rosetta’s comet is only a pixel across, but in just a few weeks, the OSIRIS camera will discern the shape of the nucleus. Things are heating up – both for the comet and for us watching the show.

Mars and moon are mates tonight / Binocular comet eludes the Lion’s bite

Mars is in conjunction with the moon tonight. Watch for the pair during early evening hours. For U.S. observers the two will be separated by about four moon diameters. Stellarium

As twilight gives way to darkness tonight, look up at the waxing moon in the south. Just above it you’ll see the planet Mars. If you’re game, whip out a pair of binoculars and see if you can spot Mars before sunset using the moon as guide.

It’s been two months now since Mars made its most recent closest approach to Earth. While the planet has faded a full magnitude and shrunk in size since opposition, it will remain the brightest ‘star’ in the evening sky until June 27, when Arcturus will outshine it by a hair.

Mars has resumed its normal eastward motion across the sky and is now on the move across Virgo. Watch for it to glide above bright Spica in mid-July and below Saturn in late August.

Mars looks very much out of round this month. It’s only about 90% illuminated and in gibbous phase. Outer planets – especially Mars – show a gibbous phase when illuminated by the sun from a very different angle than we see it on Earth. Credit: Giorgio Rizzarelli

Through a telescope it’s easy to see that its phase has changed from full to gibbous.

The inner planets Venus and Mercury show phases from crescent to half to full as they alternatively pass between Earth and sun, but the outer planets are limited to full and gibbous phases because they’re forever outside the orbit of our own planet. No passing between the sun and Earth for them.

Left: Inner planets Venus and Mercury pass through all phases from crescent to full. Outer planets appear full around opposition and gibbous when viewed from the side. The effect is most extreme at quadrature when a planet is 90 degrees from the sun. Credit: Univ. of Tennessee-Knoxville

Full phases happens around the time of opposition when Earth and an outer planet like Mars are lined up on the same side of the sun and nearest each other. We face the planet square-on and it appears fully illuminated. Several months past opposition, sunlight strikes Mars at a very different angle than what we see on Earth. We look ‘off to one side’ instead of directly at the planet; from our perspective a portion of its globe is hidden in shadow and we see it as little gibbous ‘egg’.

The shadowing effect is most extreme at ‘quadrature’ when an outer planet lies 90 degrees from the sun, ie. it’s due south at sunrise or sunset. Mars reaches eastern quadrature on July 19.

Jupiter and Saturn also show a phase effect but it’s very, very slight because they’re so far away that Earth and sun appear in nearly the same direction from their perspective. There’s very little ‘looking off to one side’ perspective compared to much closer Mars.

8th magnitude comet K1 PANSTARRS travels above the head of Leo the Lion this month. This map shows its position every 5 days with stars to magnitude 8. The stars marked Mu and Lambda are two of the bear’s claws in Ursa Major. Leo is mid-way up in the southwestern sky at nightfall. Click to enlarge. Created with Chris Marriott’s SkyMap software

Although the moon is getting brighter by the night as it approaches full phase on June 13, I see it’s time for a new map showing the ramblings of comet C/2012 K1 PANSTARRS. This reliable comet has been slowly getting brighter all spring and now has a nice 1/2-degree tail visible in 6-inch and larger telescopes. At magnitude +8, I’ve seen it plainly with 40mm binoculars from a dark sky.

Comet K1 PANSTARRS on June 1, 2014 displays a bright head and two tails – a brighter dust tail pointing east and a faint gas or ion tail. Credit: Gianluca Masi

This month it moves from the obscure constellation Leo Minor into Leo the Lion and will continue to slowly brighten. The best time to view K1 PANSTARRS is at nightfall when it’s highest in the southwestern sky.

Moonlight won’t interfere too much with viewing tonight but will be an issue in the coming nights. Dark skies return around June 15.

Give it a try – we’ve got until mid-July. After that northern hemisphere observers won’t see the comet again until morning twilight in early September.

Rosetta probe ‘dances’ its way to a very active comet

Approaching a comet involves a series of rocket burns to slow the Rosetta spacecraft down so it can enter into orbit around comet 67P/Churyumov-Gerasimenko. The second major orbital burn is scheduled for today. Credit: ESA

The European probe Rosetta has been chasing comet 67P/Churyumov-Gerasimenko for more than 10 years. This spring it’s finally catching up. But not so fast. To reach its target, the spacecraft must now slow down to match the comet’s speed. After such a long journey, it would be a shame if Rosetta overshot its objective.

Mission controllers are working this spring to throttle back the spacecraft’s speed by firing its rocket thrusters. On May 20, Rosetta did a burn for nearly 8 hours to reduce its speed relative to the comet by 650 mph (1,046 km). In space, rocket fire pushes against the spacecraft, slowing it down.

Close-up of comet 67P/C-G on 30 April 2014. The comet itself, buried inside the bright ‘nucleus’ seen in the photo is 2.5 miles across.Solar heating has vaporized ice and dust to create a fuzzy coma about 800 miles in diameter. Credit: ESA

A second burn is planned for today June 4 when Rosetta’s speed will be reduced by another 606 mph. More ‘delta-v’ burns  (shorthand for ‘change in velocity’) through the end of July will gradually drop the distance between the two until the spacecraft achieves orbit. Each firing is part of a well-choreographed dance to bring them together.

“Upon arrival in early August, we should be at a 62-mile (100 km) distance and 2.25 mph (3.6 kph) relative velocity,” says Sylvain Lodiot, Spacecraft Operations Manager.

Meanwhile, the comet is doing anything but twiddling its thumbs as the clock ticks toward August. 67P has gone from a tiny, inactive point of light to a classic fuzzy blob with a bullet-shaped coma or atmosphere now estimated at 808 miles (1,300 km) across. It’s looking like a real comet now as recent photos taken by Rosetta attest.

Artist conception of Rosetta mapping 67P from orbit starting in August. Credit: ESA

Amazing to think that the spacecraft will secure its orbit around Churyumov-Gerasimenko in August and then land a separate probe named ‘Philae’ on the surface later this fall. Can humans really do such things? Yes we can.

The Philae lander is expected to touch down on 67P on Nov. 11. It will anchor itself to the icy crust using harpoons. Credit: ESA

Amazing radar images of 209P/LINEAR, the comet behind last week’s meteor shower

Several features are visible on the comet, perhaps ridges or cliffs. This is only the fifth comet nucleus imaged by Arecibo in the last 16 years, and the most detailed. The Earth is at the bottom of these images. Credit: Arecibo Observatory/NASA/Ellen Howell, Patrick Taylor

Welcome to the dark folds of one of the closest comets in years. The 1000-foot radio telescope dish at Arecibo Observatory in Puerto Rico pinged comet 209P/LINEAR with radar between May 23-27 and reconstructed images of its rugged surface from the echoes received in return. Cliffs and ridges dominate the landscape.

Recently, dust boiled off the comet birthed a brand new meteor shower called the Camelopardalids. While forecasts cautiously predicted up to 100 meteor per hour, the actual visual rate was closer to 5-10 per hour. We learned earlier this week, the comet shed much smaller dust particles than expected. Most were below the naked eye limit when they flared across the sky. But the fact that meteor experts could actually predict a never-before-seen meteor shower is worthy of high praise.

We rarely get to image comets because they rarely make such close approaches to Earth. Today 209P/LINEAR is just 5.1 million miles from the planet, making it the closest comet to fly by Earth since Comet IRAS-Aracki-Alcock buzzed past in 1983.

Q-tip shaped 209P/LINEAR on May 26, 2014. It has a very tiny head and longish, narrow tail. Faint for its distance, the comet will require at least an 8-inch telescope to see. It’s now brightest and closest and will gradually fade. Credit: Gianluca Masi

“Comet 209P/LINEAR has no chance of hitting Earth,” said data analyst Alessondra Springmann. “It comes no closer than 5.2 million miles (8.3 million km) to Earth, safely passing our planet.”

Arecibo radar has observed other comets including 103P/Hartley 2 in 20108P/Tuttle in 2007 and 2008 and 73P/Schwassmann-Wachmann 3 in 2006. Circumstances and proximity made images of 209P/LINEAR the highest resolution of any comet ever obtained with the big dish.

The 1000-foot dish at Arecibo in Puerto Rico was used to bounce radio waves off the comet. The returning echoes contained information that was used to reconstruct images as well as position, size and rotation information. Credit: H. Schweiker/NSF

In addition to the views of its topography, radar determined 209P’s diameter at 1.5 x 1.8 miles (2.4 by 3 km) with a rotation rate of 11 hours. Although the comet travels from near Jupiter’s orbit into the inner solar system every 5.1 years, there won’t be any decent radar imaging opportunities for at least the next 50 years as there are no particularly close approaches for some time. Close approaches all depend on where the Earth is in relation to the comet when it drops into the inner solar system.

I’ve been watching 209P/LINEAR for the past 10 days and can say it’s one of the most unusual comets I’ve ever seen. Most display bright heads and long tails when this close, but not this one. It’s faint, tiny and very compact. Last night 209P shone at magnitude +12.6 and looked more like a small, fuzzy star than a comet. Because it’s so near us, the comet’s moving rapidly across the sky at the rate of a degree (two moon diameters) every few hours. I was able to detect movement in just one minute when it happened to pass near a star.

The sky is falling! Surprise meteor shower may strike Saturday morning

A brand new meteor shower shooting 100 and potentially as many as 400 meteors an hour may radiate from the dim constellation Camelopardalis below the North Star Saturday morning May 24. This map shows the sky facing north around 2 a.m. from the central U.S. Saturday.  Stellarium

Get ready for what could be the most awesome meteor shower of the year. On Saturday morning May 24 between 1 and 4 a.m. skywatchers across much of North America are in prime position to witness the birth of a brand new meteor shower – the Camelopardalids. At least 100 meteors per hour and possibly as many as 400 meteors per hour are expected with a peak viewing time around 2 a.m. Central Daylight Time. Short but sweet!

If predictions by meteor experts Peter Jenniskens of the SETI Institute and Esko Lyyttinen of Finland hold true, that morning, Earth will pass through multiple filaments of sand and pebble-sized debris trails boiled off comet 209P/LINEAR during previous passages near the sun during the 19th and early 20th centuries.

The comet was only discovered in 2004 by the Lincoln Laboratory Near-Earth Asteroid Research (LINEAR) automated sky survey. Unlike Comet Hale-Bopp and the late Comet ISON that swing by the sun once every few thousand years or million years, this one drops by every 5.1 years.

When closest at perihelion, 209P/LINEAR passes some 90 million miles from the sun. At the far end of its orbit it’s about Jupiter’s distance from the sun. In 2012, during a relatively close pass of that planet, Jupiter perturbed its orbit, bringing the comet and its debris trails to within 280,000 miles (450,000 km) of Earth’s orbit, close enough to spark a meteor shower.

When a comet nears the sun, heat vaporizes dust-laden ices from the comet’s nucleus. The solar wind ‘blows’ the dust particles into a tail which spread out along the comet’s orbit. Under the right circumstances, as with returning comet 209P/LINEAR, Earth can pass through the debris stream and we see a meteor shower as comet grit burns up in the atmosphere.

This time around, the comet itself will fly just 5 million miles from Earth on May 29 a little more than 3 weeks after perihelion, making it the 9th closest comet encounter ever observed.

You’d think this close pass would make 209P a bright sight, but it’s only predicted to reach magnitude +11, faint enough to require an 8-inch or larger telescope to see. Most likely the comet is either very small or producing dust at a very low rate or both.

Next week I’ll post maps here on how to find it. For the moment, 209P/LINEAR glows dimly at around magnitude +14 and visible in large amateur telescopes. As it speeds from the Big Dipper south to Crater the Cup over the next couple weeks, we’ll be watching it closely. Check here for updates if the comet experiences any hiccups.

The shaded area shows where the shower will be visible on May 23-24. North of the red line, the moon (a thick crescent) will be up during shower maximum around 2 a.m. CDT May 24. Click for more details. Credit: Mikhail Maslov

Meteors from 209P/LINEAR are expected to be bright and slow with speeds around 40,000 mph compared to an average of 130,000 mph for the Perseids. Most shower meteoroids are minute specks of rock, but the Camelopardalids (Cam-el-o-PAR-duh-lids) – let’s just call them ‘Cams’ –  contain a significant number of particles larger than 1mm, big enough to flare as fireballs.

Viewers in the northern half of the U.S. and southern Canada have the best seats for watching the potential shower because the radiant is midway up in the northern sky during peak viewing time Saturday morning. For points farther north, all-night twilight will blot out the fainter meteors. For observers in the far southern U.S. the radiant will be low in the northern sky, reducing meteor counts.

There’s always the chance the shower won’t materialize, so prepare yourself for that possibility. At worst we may see zero meteors, but even the most conservative estimates predict a show at least as good as the Perseids and Geminids, two of the strongest showers of the year.

But if you’re an optimist – and what skywatcher can’t afford not to be? – plan to be out before the peak and face north in a comfortable lawn chair. Bring a friend and share a cup of your favorite hot drink while you watch this ultimate wild card event.

Shower observing times across Canada and U.S.:

* Eastern Daylight Time 1:30-5 a.m. with the peak around 3 a.m.

* Central Daylight Time 12:30-4 a.m. with a 2 a.m. peak

* Mountain Daylight Time 11:30-3 a.m. with a 1 a.m. peak

* Pacific Daylight Time 10:30-2 a.m. with a peak at midnight

The dark “finger” represents streams of dust and rocks left behind by 209P/LINEAR during passes made from 1803 to 1924. Earth is shown intersecting the debris on May 23-24, 2014. Click for more details. Credit: Dr. Jeremie Vaubaillon

If it’s cloudy or you’re not in the sweet zone for viewing, the SLOOH will cover comet 209P/LINEAR live on the Web with its telescopes on the Canary Islands starting at 5 p.m. CDT (6 p.m. EDT, 4 p.m. MDT and 3 p.m. PDT) May 23 Follow-up live coverage of the new meteor shower starts at 10 p.m. CDT. The broadcast will feature astronomer Bob Berman of Astronomy Magazine; viewers can ask questions during the comet show by using hashtag #slooh.

Astrophysicist Gianluca Masi will also have a live feed of the comet at the Virtual Telescope Project website scheduled to begin at 3 p.m. CDT (8 p.m. Greenwich Time) May 22. A second meteor shower live feed will start at 12:30 a.m. CDT (5:30 a.m. Greenwich Time) Friday night/Saturday morning May 24.

No matter what, you’re covered. Later this week I’ll update with a forecast and fresh comet photos and observations. Cross your fingers!