Comet ISON is making its way through the inner solar system. Visualize its unusual orbit and track its journey
around the sun with this paper model. The background image shows comet C/2001 Q4 (NEAT). Credit: NASA and T. A. Rector (Univ. of Alaska Anchorage), Z. Levay and L. Frattare (STScI) and WIYN/NOAO/AURA/NSF
Planet orbits are so easy to picture – eight nearly concentric hula hoops centered on the sun. Comets are weirder. Their orbits vary from tapered ellipses shaped like cigars to completely open-ended parabolas and even hyperbolas. Comet ISON’s highly-elongated (stretched out) orbit is best described as hyperbolic, although that’s subject to change if Jupiter gets into the act and gives the comet a gravitational nudge during its outbound journey. As the largest planet, it has a special knack for this kind of trick, having tamed many a wayward comet’s orbit into a neat ellipse.
Comets can travel in a variety of orbits from elliptical to open-ended parabolic and hyperbolic. Credit: Wikipedia
Comets in hyperbolic and parabolic orbits are typically making their first trip to the sun from the bitterly cold and distant Oort Cloud, a roughly spherical volume of space beginning about 3,000 times Earth’s distance from the sun and extending outward to 50,000 times that distance or nearly one-quarter of the way to Alpha Centauri. The Cloud is believed to hold trillions of icy comets. Think of it as the sun’s ultimate beer cave.
To help visualize Comet ISON’s travels across the solar system we can always go the Internet and search for images and video, but sometimes it’s fun to use your own hands. Building a model using a simple cardboard template can make the knowledge “stick”. Not to mention it’s an excellent classroom activity for teachers preparing students for the comet’s post-perihelion display. All you need is this color pdf file, a printer and a few minutes to assemble.
The familiar solar system with its 8 planets occupies a tiny space inside a large spherical shell containing trillions of comets – the Oort Cloud. Credit: Wikimedia Commons
Planets’ orbits are only slightly tilted to each other, but Oort Cloud comets drop in from any angle they choose. Gravitational interactions with passing stars and clouds of interstellar gas nudge them into the inner solar system, where they’re cooked by the sun into glowing and long tails composed of vaporizing ice and dust. Long ago, some passing star gave ISON a push. It’s been falling toward the sun ever since.
Animation of Comet ISON’s orbit created by NASA
While it may be tough to picture Comet ISON’s orbit slicing the planetary racetrack at a 62-degree angle, the paper model will give you an intuitive understanding of ISON’s path and comet orbits in general.
P.S. In case you’re a klutz with a scissors just click on the Youtube video above.
Comet R1 Lovejoy passes the Beehive Cluster: (Credit Damian Peach).
Tired of comets yet? Right now, northern hemisphere observers have four (!) comets within range of binoculars in the dawn sky. Comet C/2012 S1 ISON, is, of course, expected to dazzle towards month’s end. Comet 2P/Encke is an “old standby,” with the shortest orbital period of any comet known at 3.3 years, and is making a favorable appearance this Fall. And comet C/2012 X1 LINEAR added to the morning display recently, reaching about +8th magnitude in an unexpected outburst…
But the brightest and best placed comet for morning viewing is currently Comet C/2013 R1 Lovejoy. Shining at +6th magnitude, R1 Lovejoy just passed into the constellation Leo after a photogenic pass near the Beehive Cluster (M44) in Cancer last week. We caught sight of R1 Lovejoy a few mornings ago, and it’s an easy binocular object, looking like a fuzzy unresolved globular cluster with barely the hint of a tail.
If the name sounds familiar, that’s because the comet was discovered by Australian observer Terry Lovejoy, the prolific discoverer of four comets, including the brilliant sungrazing Comet C/2011 W3 Lovejoy that survived its 140,000 kilometre perihelion passage above the surface of the Sun on December 16th and went on to dazzle southern hemisphere observers in late 2011 and early 2012.
Comet R1 Lovejoy as imaged by Rob Sparks (@HalfAstro) from Tucson, Arizona passing near the Beehive cluster. (Credit: Rob Sparks).
Terry discovered R1 Lovejoy on September 7th, 2013 while it was still at magnitude +14.4. The comet is expected to top out at +4th magnitude in late November as it passes 61.4 million kilometres from Earth on November 19th and heads for perihelion at 0.877 AUs from the Sun on December 25nd, 2013. Comet R1 Lovejoy is on a 64 degree orbit highly inclined to the ecliptic, and has a period roughly 7,000 years long. The last time R1 Lovejoy graced Earthly skies, our early ancestors still thought copper smelting was a pretty hip idea!
The orbital path of Comet R1 Lovejoy through the inner solar system. (Credit: NASA/JPL Solar System Dynamics explorer).
And unlike comets Encke and ISON that are plunging near the Sun, Comet R1 Lovejoy never gets closer than 19 degrees elongation from our nearest star in late December. It also reaches a maximum northern declination of 43 degrees on November 28th, the same day that ISON reaches perihelion. For mid-latitude northern hemisphere observers, R1 Lovejoy will remain well placed at 35 to 45 degrees above the northeastern horizon about an hour before sunrise through late November.
Here are some key dates to aid you in your quest to spy Comet R1 Lovejoy in late November:
November 11th: Passes near +4.5 Kappa Leonis.
November 14th: Passes from Leo into the constellation Leo Minor & passes near the +5.3 star 20 Leonis Minoris.
November 16th: Passes near the +5th magnitude stars 28, 30, and 34 Leonis Minoris.
November 18th: Passes into the constellation Ursa Major.
November 19th: Passes near the +4.8 magnitude star 55 Ursae Majoris & +5.3 magnitude star 57 Ursae Majoris.
November 19th: Closest to Earth, at 0.4 AUs distant.
The celestial path of Comet R1 Lovejoy spanning November 11th to the 30th. (Created using Starry Night Education software).
November 21st: Passes into the constellation Canes Venatici.
November 22nd: Passes near the +6th magnitude star 4 Canum Venaticorum & the +4.2 magnitude star Chara (Beta Canum Venaticorum).
November 24th: Passes near the Sunflower Galaxy (M63).
November 27th: Passes into the constellation Boötes.
December 1st: Passes near +3.5 magnitude star Nekkar (Beta Boötis).
December 4th: crosses into Corona Borealis.
Note that passes on the list above denote passages closer than one degree of Comet R1 Lovejoy near bright objects.
Perihelion for the comet is December 25th at 0.877 AU, and its closest approach to Earth is November 19th. On this date, it will also be moving at its maximum apparent speed as seen from Earth, covering about 3 degrees of the sky every 24 hours, or the angular span of the Full Moon every 4 hours.
United Kingdom observer Pete Lawrence imaged Comet R1 Lovejoy this past weekend from his backyard garden using a 4-inch apochromatic refractor and a Canon 40D DSLR:
Comet R1 Lovejoy as imaged by Pete Lawrence on November 9th. (Credit: Pete Lawrence).
He also made his first confirmed binocular sighting of Comet ISON using a pair of 15×70 binocs, noting to Universe Today that “ISON’s head appears to be small and stellar compared to Lovejoy’s extended coma, which is obvious in binoculars, and also brighter!”
It’s worth noting that all four of these morning comets are on separate orbital paths, and only seem to be in the same general region of the sky as seen from our Earthly vantage point… and none of them are passing near the Earth!
This week is also a good time to hunt for comets in the pre-dawn sky for another reason: the Moon reaches Full this coming weekend on Sunday, November 17th. After this week, it will start to creep into the morning sky and interfere with deep sky observations for the next two weeks.
Comet R1 Lovejoy imaged on November 10th by astrophtographer Justin Ng. (Credit: Justin Ng).
It’s also interesting to note that amateur observers discovered two more faint comets this past weekend. Though comets C/2013 V3 Nevski and C/2013 V2 Borisov aren’t slated to be anything spectacular, that brings the number of amateur discoveries to 13 for 2013. Are amateur comet hunters mounting a comeback?
In this age of automated surveys, the question is often raised as to whether amateurs can still discover comets. Keep in mind, Terry Lovejoy found Comet R1 Lovejoy with a medium-sized 8-inch Schmidt Cassegrain reflecting telescope… the age of amateur comet hunters seemes far from over in 2013!
Two new tail streamers are visible between Comet ISON's green coma and bright star near center. in this photo taken on Nov. 6. They're possibly the beginning of an ion tail. Click to enlarge. Credit: Damian Peach
I’m starting to get the chills about Comet ISON. I can’t help it. With practically every telescope turned the comet’s way fewer than three short weeks before perihelion, every week brings new images and developments. The latest pictures show a brand new tail feature emerging from the comet’s bulbous coma. For months, amateur and professional astronomers alike have watched ISON’s slowly growing dust tail that now stretches nearly half a degree or a full moon’s diameter. In the past two days, photos taken by amateur astronomers reveal what appears to be a nascent ion or gas tail. Damian Peach’s Nov. 6 image clearly shows two spindly streamers.
Early detection of ISON’s possible ion tail on Oct. 31 by amateur astronomer Efrain Morales Rivera in a 12-inch telescope.
The comet on Nov. 4 also shows the new tail structures extending farther from the coma. Credit: Justin Ng
Ion tails are composed of gases like carbon monoxide and carbon dioxide blown into a narrow straight tail by the solar wind and electrified to fluorescence by the sun’s ultraviolet light. Being made of ions (charged particles), they interact with the sun’s wind of charged particles. Changes in the intensity and direction of the magnetic field associated with sun’s exhalations kink and twist ion tails into strange shapes. Strong particle blasts can even snap off an ion tail. Not that a comet could care. Like a lizard, it grows a new one back a day or three later.
Comet ISON plunges sunward across Virgo in the coming days. Watch for it low in the eastern sky shortly before the start of dawn. Click to enlarge and print for outdoor use. Stellarium
A fresh forked tail isn’t ISON’s only new adornment. Its inner coma, location of the bright “false nucleus”, is becoming more compact, and the overall magnitude of the comet has been slowly but steadily rising. Two mornings ago I pointed a pair of 10×50 binoculars ISON’s way and was surprised to see it glowing at magnitude 8.5. Things happen quickly now that the comet is picking up speed While it appeared as little more than a small smudge, any comet crossing into binocular territory is cause for excitement. Other observers are reporting magnitudes as bright as 8.0. Estimates may vary among observers, but the trend is up. Seiichi Yoshida’s excellent Weekly Information about Bright Comets site predicts another half magnitude brightening over the next few days. You can use the map here to spot it in your own glass before the moon returns to the morning sky.
False color photo taken with the TRAPPIST 60-cm telescope using a narrowband CN (390 nm) filter at 8:45 Universal Time Nov. 5 shows two active jets (small double-plume) in ISON’s inner coma (right) and the dust tail at left. Field of view is 5×5 arc minutes. North is up, east to the left. Credit: Cyrielle Opitom, TRAPPIST team
But wait, there’s more. Emmanuel Jehin, a member of the TRAPPIST ( TRAnsiting Planets and PlanetesImals inSmall Telescopes) team, a group of astronomers dedicated to the detection of exoplanets and the study of comets and other small solar system bodies, reports a rapid rise in ISON’s gas production rate in the past several days. They’ve increased by a factor of two since Nov. 3. Could the spike be connected to the development of an ion tail? Jehin and team have also recorded two active jets coming from the comet’s nucleus using specialized filters. Dust production rates however have remained flat.
The Comet ISON Observing Campaign is both terrestrial and celestial. Nine different NASA and ESA spacecraft, eight of which are shown here, have observed comet ISON so far. Credit: NASA/ESA
Casey Lisse of the Comet ISON Observing campaign (CIOC) reports that the Chandra X-ray Observatory just became the 9th spacecraft to image the comet . More details and photos should be available soon. The campaign predicts the comet will peak in brightness between -3 to -5 magnitude when it zips closest to the sun on Nov. 28. Want to ride alongside the comet during its passage through the inner solar system? Click on this awesome, interactive simulator.
Hubble Space Telescope image of comet C/1999 S4 (LINEAR) that disintegrated around July 23, 2000. Credit: NASA/ESA
Because ISON is a fresh-faced visitor from the distant Oort Cloudthat will soon face the full fury of the sun, speculation of its fate has ranged across the spectrum. Everything from breakup and dissolution before perihelion to surviving intact trailing a spectacular dust tail. The comet is currently approaching the 0.8 A.U. mark (74.4 million miles / 120 million km) when previous comets C/1999 S4 LINEAR in 2000 and C/2010 X1 Elenin in 2011 crumbled to pieces and vaporized away. Will ISON have the internal strength to pass the test and venture further into the solar boil? Should it survive, it faces a formidable foe – the sun. Both the intense solar heat and gravitational stress on the comet’s nucleus could easily tear it apart. If this happens a few days before perihelion we’ll be left with little to see, but if ISON busts up a day or two after perihelion, watch out baby. When the comet reappears in the morning sky, it may be missing its head but make it up for the loss with a spectacular tail of fresh dust and ice many degrees in length. This is exactly what happened to Comet C/2011 W3 (Lovejoy) in December 2011. After its close graze with the home star, the nucleus disintegrated, producing a striking tail seen by skywatchers in the southern hemisphere.
Pictures of Comet C/2011 W3 Lovejoy on Dec. 22, 2011 after perihelion passage. Will ISON be a repeat? Credit: Chris Wyatt
The final scenario sees Comet ISON pushing past all barriers intact and ready to put on a splendid show. Whatever happens, I suspect we’re in for surprises ahead. For a more detailed analysis of these possibilities I invite you check out Matthew Knight’s blog on the CIOC website.
We interrupt your regular Weekly Space Hangout for an hour-long special on Comet ISON, broadcast live from the Pacific Space Centre in Vancouver, BC.
We’ve got special guests +Pamela Gay, +Nicole Gugliucci, +David Dickinson and Sondy Springmann to discuss the upcoming arrival of Comet ISON.
We’ll discuss the history of the comet, review its orbit, and give you tips and tricks for how you can participate in this amazing event (or non-event).
We record the Weekly Space Hangout every Friday at 12:00 pm Pacific / 3:00 pm Eastern. You can watch us live on Google+, Universe Today, or the Universe Today YouTube page.
Universe Today is proud to announce that we are partnering with OPT Telescopes and SpaceWeather.com for a brand new Comet ISON Photo Contest, with over $10,000 in prizes to give away!
Comet ISON is one of the most anticipated sky events for years, and already astrophotographers have been busy trying to capture images of this comet. But as it gets closer to the Sun, hopefully it will become even brighter and visible to more people – not just the astrophotographers with the really great equipment!
This new photo contest features several different chances to win some great prizes, thanks to OPT Telescopes, the folks behind this contest. There will be a popular vote on Facebook with winners of first, second and third places, as well as images judged by a panel of experts with three winners in that category as well.
And so its not just about having great equipment. “It’s about the overall image and it can be in any ‘style’ at all,” says OPT Telescopes. “We’ve seen some amazing submissions shot with DSLR’s and point and shoot digital cameras in the past, and encourage everyone, regardless of skill level or equipment owned, to participate.”
Who can participate? Anyone aged 13 years and older who has a valid email address. (Employees of OPT, Universe Today and Spaceweather.com are not eligible for entry.) Images must be the original work of the contestant.
The contest begins today, November 1st, 2013 and ends midnight December 31st, 2013. Winners will be announced by January 7, 2014.
There are two ways to enter:
The first is through Facebook on this OPT Telescope page. Entrants are required to submit their date of birth, email address, real name and technical information about their image and location captured, as well as “liking” OPT Telescopes on Facebook.
Your image will become part of OPT’s Facebook gallery. One image, per day, per entrant is allowed.
If you’d rather not go through Facebook, you may submit via email to this address. Emailed entries are also required to list date of birth, and information about their image in regard to equipment used and location captured. All emailed submissions will be manually entered onto the OPT Facebook gallery to participate in the popular vote. Again, one image, per day, per entrant is allowed.
We also encourage those who enter to also upload their images to Universe Today’s Flickr Group page, so more people can see your images! We also feature many of the images uploaded there in our articles.
What are the prizes? As of November 1st, the prize donations are still rolling in! We now have over $10,000 in astronomy gear to give away to the winners of this contest. Final prize packages will be announced November 5th. So, stay tuned.
Comet Lovejoy on November 2, 2013, as seen from Singapore. Credit and copyright: Justin Ng.
While many are anticipating seeing Comet ISON, there’s more in the sky these days than just one comet. There are actually four comets now in the skies in the mornings — in addition to ISON, there’s comets 2013 R1 Lovejoy, 2P/Encke and 2012 X1 LINEAR! Unfortunately, none of these are visible to the naked eye — yet anyway.
Here are some great recent images and video of these comet taken by amateur astrophotographers. Above is Comet Lovejoy, just taken by Justin Ng from Singapore . “Comet Lovejoy will share the same part of the sky as Comet ISON this month and it presents a cool astrophotography opportunity for skywatchers and astronomers,” Justin told Universe Today via email. “This image is a result of stacking 9 images together and each image was captured using a 3 inch telescope at 5 minutes exposure time for about an hour before dawn.”
Comet 2P/Encke on October 30, 2013. The coma is partially obscuring the small barred spiral galaxy NGC 4371. Credit and copyright: Damian Peach.
A gorgeous shot of Comet Encke by Damian Peach. “The fine narrow ion tail is very nicely defined which has recently developed,” Damian said via email.
Below is Damian’s image of Comet Lovejoy. “Looks as though a disconnection event may have occurred within Lovejoy’s gas tail,” Damian said. “Note the broad fan shaped condensation around half way along the tail.”
Comet 2013 R1 Lovejoy on Oct 31, 2013. Credit and copyright: Damian Peach.
Here are two great timelapses of Comet ISON! The first is from Justin Ng from Singapore, taken on October 27:
A recent look at ISON from Efrain Morales with black & white matched with a negative view:
Comet ISON C/2012 S1 On October 31st, 09:17-34 UTC. Coma much denser now around the nucleus and possibly both tails (Ion, Dust) on negative image (lower right) 17 x 1 minute exposures. Credit and copyright: Efrain Morales/Jaicoa Observatory
A nice shot of Comet Lovejoy nearby in the sky to the bright binary star system Procyon in Canus Minor:
Procyon and Comet Lovejoy in the morning sky on October 31, 2013, from Arizona. Credit and copyright: Robert Sparks.
Want to get your astrophoto featured on Universe Today? Join our Flickr group or send us your images by email (this means you’re giving us permission to post them). Please explain what’s in the picture, when you took it, the equipment you used, etc.
According to a new study, meteors may be less dangerous than we thought, thanks to Earth's atmosphere. Credit: David A Aguilar (CfA).
How did life on Earth originally develop from random organic compounds into living, evolving cells? It may have relied on impacts by enormous meteorites and comets — the same sort of catastrophic events that helped bring an end to the dinosaurs’ reign 65 million years ago. In fact, ancient impact craters might be precisely where life was able to develop on an otherwise hostile primordial Earth.
“This is bigger than finding any dinosaur. This is what we’ve all searched for – the Holy Grail of science,” Chatterjee said.
Our planet wasn’t always the life-friendly “blue marble” that we know and love today. At one point early in its history it was anything but hospitable to life as we know it.
“When the Earth formed some 4.5 billion years ago, it was a sterile planet inhospitable to living organisms,” Chatterjee said. “It was a seething cauldron of erupting volcanoes, raining meteors and hot, noxious gasses. One billion years later, it was a placid, watery planet teeming with microbial life – the ancestors to all living things.”
Exactly how did this transition happen? That’s the Big Question in paleontology, and Chatterjee believes he may have found the answer lying within some of the world’s oldest and largest impact craters.
After studying the environments of the oldest known fossil-containing rocks in Greenland, Australia and South Africa, Chatterjee said these could be remnants of ancient craters and may be the very spots where life began in deep, dark and hot environments — similar to what’s found near thermal vents in today’s oceans.
Larger meteorites that created impact basins of about 350 miles in diameter inadvertently became the perfect crucibles, according to Chatterjee. These meteorites also punched through the Earth’s crust, creating volcanically driven geothermal vents. They also brought the basic building blocks of life that could be concentrated and polymerized in the crater basins.
In addition to new organic compounds — and, in the case of comets, considerable amounts of water — impacting bodies may also have brought the necessary lipids needed to help protect RNA and allow it to develop further.
“RNA molecules are very unstable. In vent environments, they would decompose quickly. Some catalysts, such as simple proteins, were necessary for primitive RNA to replicate and metabolize,” Chatterjee said. “Meteorites brought this fatty lipid material to early Earth.”
How organic compounds in crater basins were encapsulated in lipid membranes and became the first cells (Chatterjee)
Based on research in Australia by University of California professor David Deamer, the ingredients for all-important cell membranes were delivered to Earth via meteorites and existed in water-filled craters.
“This fatty lipid material floated on top of the water surface of crater basins but moved to the bottom by convection currents,” suggests Chatterjee. “At some point in this process during the course of millions of years, this fatty membrane could have encapsulated simple RNA and proteins together like a soap bubble. The RNA and protein molecules begin interacting and communicating. Eventually RNA gave way to DNA – a much more stable compound – and with the development of the genetic code, the first cells divided.”
And the rest, as they say, is history. (Well, biology really, and no small amount of chemistry and paleontology… and some astrophysics… well you get the idea.)
Chatterjee recognizes that further experiments will be needed to help support or refute this hypothesis. He will present his findings Oct. 30 during the 125th Anniversary Annual Meeting of the Geological Society of America in Denver, Colorado.
No fewer than four bright-ish comets greet skywatchers an hour before the start of dawn. From upper left counterclockwise: C/2013 R1 Lovejoy, 2P/Encke, C/2012 X1 and ISON. Credits: Gerald Rhemann, Damian Peach, Gianluca Masi and Gerald Rhemann
Get your astronomical trick-or-treat bags ready. An excursion under the Halloween morning sky will allow you fill it in a hurry — with comets! We’ve known for months that ISON and 2P/Enckewould flick their tails in the October dawn, but no one could predict they’d be joined by Terry Lovejoy’s recent comet discovery, C/2013 R1 (Lovejoy), and the obscure C/2012 X1 (LINEAR). The last surprised all of us when it suddenly brightened by more than 200 times in a matter of days. Almost overnight, a comet found on precious few observing lists became bright enough to see in binoculars. Now comet watchers the world over are losing sleep to get a glimpse of it.
Rarely are four comets this bright in the same quadrant of sky. This map shows the sky facing east about two hours before sunrise on Oct. 31. Take note of the three stars are labeled “Beta”. These are (from top) Beta Cancri, Beta Leonis and Beta Coma Berenices. We’ll use these three stars and the planet Mars to hone in on the comets’ locations in the maps below. Stellarium
Since it’s unusual to have four relatively bright comets in the same chunk of sky at the same time, you don’t want to miss this opportunity. Now that the moon has dwindled to the slightest crescent, this is THE time to hunt for these ghostly apparitions before dawn.
Detailed (updated) map showing Comet Lovejoy’s progress across Cancer in the coming days. It passes very close to the Beehive Cluster on Nov. 6-7. Click for a larger version you can print and use under the stars. All dates are at 6 a.m. CDT; north is up and west to the right and stars are shown to mag. 5. All closeup charts created with Chris Marriott’s SkyMap software
Brightest of the bunch at magnitude 8 and your best bet to see in a standard pair of 50mm binoculars is Comet Lovejoy. Using the maps, look for a round, fuzzy spot with a brighter center not far from the bright star Procyon in Canis Minor. In the coming days, Lovejoy will brighten by an additional 2 to 3 magnitudes as it trucks across Cancer headed toward the Big Dipper. This is one to watch. Lovejoy will likely reach naked eye brightness by mid-November. Small telescope users can see the comet with ease but its developing gas tail is still to faint to spot visually.
Comet Encke drops below Leo and into Virgo over the next two weeks. Your guide star Beta Leo is at upper right. Stars to mag.8. Click to enlarge.
Comet Encke treks around the sun every 3.3 years. Sometimes it’s well placed for viewing and sometimes not. Because of its short period, dedicated comet watchers meet up with it a half dozen or more times during their lives. This apparition is a favorable one with the comet well-positioned in the east at dawn near peak brightness. Current estimates place it magnitude 7.5-8 with only the wispiest of tails. Like Lovejoy, 50mm binoculars under a dark sky should nab it.
A week before Encke reaches its peak magnitude of 6 or 7 at perihelion on Nov. 21, it chases the into the glare of morning twilight. If you want to see this comet, you’ve got about 2 weeks of viewing time left. Make sure to set up in a place with an open view to the east-southeast or you’ll find it hidden by the treeline.
Animation from images taken Oct. 25 and 28 of comet C/2012 X1 (LINEAR) showing its rapidly expanding coma in the wake of an eruptive event in its icy crust. Click image to animate. Credit: Gianluca Masi
Comet C/2012 X1 would have deprived us of a unique sight had it followed the rules. Instead, an eruption of fresh, dust-laden ices from its surface blasted into space to form a gigantic glowing sphere of material that vaulted the comet’s magnitude from a wimpy 13.5 to a vol-luminous 7.5. That’s a difference of 6 magnitudes or a brightness factor of 250 times!
Outbursts of this consequence are rare; the best example of a similar blow-out happened in 2007 when Comet 17P/Holmes cut loose and brightened by half a million times from magnitude 17 to 2.8 in just under two days.
C/2012 X1 (LINEAR) hovers low in the northeast in Coma Berenices near Beta. Because it’s much further from Earth than the other three comets, it moves more slowly across the sky. It has a close conjunction with the brilliant star Arcturus in mid-November. In this map, north is at top left and west to top right. Stars to mag. 8. Click to enlarge.
As with any explosion, the cloud of debris around C/2012 X1 continues to expand. Presently measuring a healthy ~8 arc minutes in diameter (1/4 the size of the full moon), the comet will almost certainly continue to grow and fade with time. Catch it now with binoculars and small telescopes before its veil-like coma thins to invisibility. Like Encke, X1 LINEAR requires an open eastern horizon and best viewed at the start of dawn. Make it the last comet on your observing list after Lovejoy, Encke and ISON.
Mars and several other moderately bright stars in Leo will guide you to Comet ISON in the next week or two. Stars to mag. 10. Click to enlarge.
Ah, ISON. Halloween morning wouldn’t be complete without a visit to this year’s the most anticipated comet.. If it can hold itself together after a searing graze of the sun on November 28, the comet will undoubtedly become a most pleasing sight during the first three weeks of December. Right now it’s a little behind schedule on brightness, but don’t let that worry you – its best days are still ahead.
One of the finest pictures to date of Comet ISON by ace astrophotographer Damian Peach taken on Oct. 27.
Of our four morning treats, Comet ISON is currently the faintest at around magnitude 9.5. Observers with binoculars in the 70-100mm range will see it under dark skies but most of us will need a 6-inch or larger scope at least until mid-November. That’s when ISON’s expected to brighten to magnitude 6, the naked eye limit. Just before it slips into the solar glare, ISON could reach 3rd magnitude around Nov. 21, normally an easy catch with the naked eye, but low altitude will hamper the view.
So open your bag wide tomorrow before dawn and keep it open the next few mornings. Trick or treat!
Artist's conception of a comet exploding in the Earth’s atmosphere above Egypt. Credit: Terry Bakker
Speak about destruction. A comet slammed into Earth’s atmosphere 28 million years ago and basically killed everything with fire below, leaving a huge deposit of yellow silica glass in its wake, a team of astronomers say.
The evidence — a black pebble found by an Egyptian geologist within this vast tract of glass — is believed to be a part of the comet’s nucleus or heart and not just an ordinary meteorite. The team says this could be the first hard evidence, so to speak, of a comet striking Earth.
The temporary “shockwave of fire” hit 2,300 square miles (roughly 6,000 square kilometers) of Egyptian sand, turning the grains into glass. Given the area’s rich archaeological history, it’s probably not too much of a surprise that a small portion of this is visible in a brooch that belonged to ancient boy-king Tutankhamun.
A brooch that belonged to the Egyptian boy-king Tutankhamun, which reportedly contains a silica glass stone that originated from a comet explosion. Credit: University of the Witwatersrand, Johannesburg
“It’s a typical scientific euphoria when you eliminate all other options and come to the realization of what it must be,” said lead author Jan Kramers of the University of Johannesburg in a statement.
Besides silica, the cosmic blast furnace left teeny-tiny diamonds in its wake, forming from carbon. “Normally they form deep in the earth, where the pressure is high, but you can also generate very high pressure with shock. Part of the comet impacted and the shock of the impact produced the diamonds,” said Kramers.
More information on this find should be available soon when the discovery is published in Earth and Planetary Science Letters. The authors first discussed their find in a public lecture Oct. 10. It will be interesting to see what other scientific teams think of this hypothesis, so stay tuned for the reaction.
Source: University of the Witwartersrand, Johannesburg
Color image of Comet ISON on October 27, 2013. Credit and copyright: Damian Peach.
Astrophotographers were out in full force this weekend to try and capture the bonanza of comets now visible in the early morning skies! You’ll need a good-sized telescope to see these comets for yourself, however, but with the Moon now waning means darker skies and better observing conditions. Above is an absolutely gorgeous image of Comet ISON taken by Damian Peach. See below for more images of not only Comet ISON, but also Comet Encke, Comet Lovejoy and Comet LINEAR — now in outburst.
In fact, one of our “regular” contributors, John Chumack, captured all four comets in one morning, on Saturday October 26!
Four comets captured in one morning! Clockwise from top left: Comet ISON 2012 S1; Lovejoy C/2103 R1;, 2P ENCKE, Linear 2012 X1. Credit and copyright: John Chumack/Galactic Images.
Here’s what John said about his Comet ISON image: “The tail extends off the frame it is at least 20 arc minutes long now and the coma is still around 3-4 arc minutes in diameter. The comet is looking good at about 12th magnitude and continues to slowly brighten, just 30 more days to perihelion — closest point to the Sun. Hopefully it puts on a good show for all of December too!”
And Comet Linear 2012 X1 was at 14th magnitude, but now in outburst, John said, “it is over 100-fold brighter at 8th magnitude and expanding! It was low on the horizon at dawn, and tough to get. It just cleared the trees at 7:07am in bright dawn light! I managed a couple of quick shots before my CCD was flooded completely with light!”
Of Comet Lovejoy, John said, “I found it has developed a faint long tail…it is at least 12 arc minutes in length and the comet’s coma is now around 6 arc minutes in diameter. I already notified Terry Lovejoy in Australia and he was excited to hear his comet has developed a new tail!”
Here’s a timelapse video from John of Comet Lovejoy moving through the constellation of Canus Minor:
Here’s a view from a smaller telescope from Tom Wildoner, to give a better idea of what “most of us” would see with our humbler telescopes!
The view of Mars and Comet ISON on the morning of October 28, 2013. taken using a 75mm lens, 30 seconds at ISO 800. Look for the small blur inside the yellow circle. Credit and copyright: Tom Wildoner.Comet 2012 1X (LINEAR) on October 28, 2013 following its recent outburst. Obtained under bright twilight, low altitude and moonlight! Credit and copyright: Damian Peach.Comet ISON Nucleus on October 26, 2013 at 9:43 – 10:27 U.T. Taken with QHY8 CCD & Homemade 16″ Newtonian telescope. A total of 40 minutes of exposure (20 x 120 second exposures). Credit and copyright: John Chumack/Galactic Images.
Even NASA astronomers were out trying to take images of these comets. Here’s an image taken from NASA’s Marshall Spaceflight Center:
Comet ISON on October 25, 2013, taken with a 14 inch telescope at NASA’s Marshall Space Flight Center in Huntsville, Alabama. Credit: NASA/MSFC/Aaron Kingery
NASA explains the image:
In the early morning of Oct. 25 (6:45 a.m. EDT), NASA’s Marshall Space Flight Center in Huntsville, Ala., used a 14″ telescope to capture this image of Comet C/2012 S1 (ISON), which is brightening as it approaches the sun. The comet shines with a faint green color just to the left of center. The diagonal streak right of center was caused by the Italian SkyMed-2 satellite passing though the field of view. At magnitude 8.5, the comet is still too faint for the unaided eye or small binoculars, but it’s an easy target in a small telescope.
At this time of this image, ISON was located in the constellation of Leo the Lion, some 132 million miles from Earth and heading in toward the sun at 87,900 miles per hour.
Want to get your astrophoto featured on Universe Today? Join our Flickr group or send us your images by email (this means you’re giving us permission to post them). Please explain what’s in the picture, when you took it, the equipment you used, etc.
