Comets


Comet 2

NASA scientists struggle to understand signs of massive climate shift on Jupiter as giant planet is bombarded with cometary debris

Jia-Rui Cook
jpl.nasa.gov
Wed, 17 Oct 2012 14:43 UTC
Image
© NASA/IRTF/JPL-Caltech/G. Hall/University of the Basque CountryJupiter has been suffering more impacts over the last four years than ever previously observed, including this meteoroid impact on Sept. 10, 2012. The left-hand image was taken from a red-filtered video by amateur astronomer George Hall of Dallas, Texas, on Sept. 10 and processed by Ricardo Hueso (University of the Basque Country, Bilbao, Spain). The right-hand image is an infrared image from NASA’s Infrared Telescope Facility on Mauna Kea, Hawaii, taken on Sept. 11. Scientists compare the visible-light images to the infrared images to learn about the fireball's disruption of the Jovian atmosphere. In this case, the infrared view reveals no long-term disturbance. The circles in the annotated version indicate where the impact occurred. Scientists think the fireball was caused by an object less than 45 feet (15 meters) in diameter.
Jupiter, the mythical god of sky and thunder, would certainly be pleased at all the changes afoot at his namesake planet. As the planet gets peppered continually with small space rocks, wide belts of the atmosphere are changing color, hotspots are vanishing and reappearing, and clouds are gathering over one part of Jupiter, while dissipating over another. The results were presented today by Glenn Orton, a senior research scientist at NASA's Jet Propulsion Laboratory, Pasadena, Calif., at the American Astronomical Society's Division for Planetary Sciences Meeting in Reno, Nev.

"The changes we're seeing in Jupiter are global in scale," Orton said. "We've seen some of these before, but never with modern instrumentation to clue us in on what's going on. Other changes haven't been seen in decades, and some regions have never been in the state they're appearing in now. At the same time, we've never seen so many things striking Jupiter. Right now, we're trying to figure out why this is all happening."

Comment: For how much longer can Jupiter vacuum the larger incoming chunks and take the hit for us?

Just remember where you heard it first folks, Something Wicked This Way Comes...



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Comet

New Comet P/2012 T1 (PANSTARRS)


G.V.Schiaparelli Astronomical Observatory
Fri, 12 Oct 2012 13:56 UTC
New Comet P/2012 T1
© "G.V.Schiaparelli" Astronomical Observatory
P/2012 T1 (PANSTARRS) was discovered by the PAN-STARRS survey on 2012, Oct. 06.53 with a 1.8-m reflector + CCD located at Haleakala, HI, USA.

Richard Wainscoat, Henry Hsieh and Larry Denneau described the object to have a PSF larger than stars nearby (1.5″ vs 1.07″). The object was posted on the NEO Confirmation Page under the temprary designation P104kFN.

Apart from their internal confirmation team from Hawaii (Dave Tholen, Marco Micheli and Garrett T. Elliott using the UoH 2.24-m reflector), observatories from the "T3 project" were the only ones to confirm it as a comet.

The first who reported to us cometary activity was Hidetaka Sato, using a 0.43-m remotely from New Mexico on Oct. 10.3, noted that "P104kFN is a potential comet with a round coma of 10″ in diameter. A tail was 12″ toward PA 250 degree."

After his observation I managed to observe it under a clear sky the following night (the first after three weeks of bad weather in northern Italy!), confirming its clear cometary appearance: in a stack of 56 minutes of total exposure time in good conditions, it has a diffuse aspect, with a coma 10″ wide elongated in PA 253° for at least 15″.
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Comet 2

Storm warning: Earth to pass through dense trail of Comet LINEAR in May 2014

Kelly Beatty
Sky&Telescope
Tue, 09 Oct 2012 14:10 UTC
On May 24, 2014, Earth will plow through a dense stream of dust particles shed by Comet 209P/LINEAR. Dynamicists think the crossing could result in an intense meteor shower - maybe even a "storm" - and North Americans will have front-row seats.

Over the past two decades, celestial dynamicists have gotten very good at divining when meteoric activity will spike. Their computer models can track how dust ejected by a comet near each perihelion pass gets distributed into strands of particles over time. Their calculations show that dust tends to stay concentrated close to the nucleus, and that the strands themselves often converge in space close to the orbit's perihelion.

Now these number-crunchers are telling us make sure May 24, 2014, is circled on our skywatching calendars. On that date, we might experience the most dramatic display of "shooting stars" in more than a decade.
Meteor Shower
© NASA / JPL / HorizonsAccording to predictions, a little-known comet will pass perihelion in early May of 2014 and, two weeks later, sandblast Earth with dust particles spread along its orbit.
The source of all this buzz is a little-known periodic comet called 209P/LINEAR. Discovered by an automated sky survey in 2004, it follows a looping but relatively tight path that carries it just inside Earth's orbit every 5.04 years. According to dynamicist Syuichi Nakano, Comet 209P/LINEAR's next perihelion occurs on May 6, 2014, at a point 0.969 astronomical unit from the Sun and with Earth not far away.
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Fireball

Comet-like material detected around Beta Pictoris


Sci-News.com
Mon, 08 Oct 2012 22:07 UTC
Astronomers using ESA's Herschel Space Observatory have detected magnesium-rich material in a dust belt around the young star Beta Pictoris. Beta Pictoris is a 12-million-year-old star lying about 63 light-years from Earth. The star hosts a gas giant planet, discovered in 2008, along with a dusty debris disc that could, in time, evolve into a torus of icy bodies much like the Kuiper Belt found in our own Solar system.

Using the unique observing capabilities of Herschel, astronomers have for the first time determined the composition of the dust in the cold outskirts of this planetary system. Of particular interest was the mineral olivine, which crystallizes out of the protoplanetary disc material close to newborn stars and is eventually incorporated into asteroids, comets and planets.
Image
© ESO /A.-M. Lagrange et alThis composite image shows the close environment of Beta Pictoris as seen in near infrared light. The outer part of the image shows the reflected light on the dust disc, as observed in 1996 with the ADONIS instrument on ESO’s 3.6 m telescope; the inner part is the innermost part of the system, as seen at 3.6 microns with NACO on the Very Large Telescope. Astronomers using ESA’s Herschel Space Observatory have recently detected the mineral olivine in a dust belt around this young star
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Fireball

Further analysis on the September 21st meteor or comet fragment that "skipped" around the world

Nancy Atkinson
Universe Today
Mon, 08 Oct 2012 19:48 UTC

The meteoroid seen over the UK on September 21, 2012 has created quite a sensation - make that a several sensations. First, the bright object(s) in the night sky were seen across a wide area by many people, and the brightness and duration - 40 to 60 seconds reported and videoed by some observers - had some experts wondering if the slow moving light-show might have been caused by space junk. But analysis by satellite tracker Marco Langbroek revealed this was likely an Aten asteroid, asteroid which have orbits that often cross the Earth's orbit, but their average distance from the Sun is less than 1 AU, the distance from the Earth to the Sun.

Atens are fairly unusual, making this a rather unique event. But then came another analysis that seemed to be so crazy, it might have been true: this meteoroid may have skipped like a stone in and out of Earth's atmosphere, where it slowed enough to orbit the Earth until appearing as another meteor over Canada, just a few hours after it was seen over the UK and northern Europe.

How amazing that would have been! And there was much speculation about this possibility. But, it turns out, after more details emerged and further investigation ensued, it is not possible that the space rock could have boomeranged around the world and been seen in two different hemispheres.

Comment: Of course the fireballs seen in the UK were not the exact same as those seen later in the US and Canada... the above analysis misses the point that they could have been fragments coming off the same larger body. Universe Today doth protesteth too much in its effort to pooh-pooh the notion of Tunguska-class bodies passing so close to Earth during these times.

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Meteor

Next year's "brightest comet in modern times" to be "once in a civilization" event


Scientific American
Sat, 06 Oct 2012 06:05 UTC
Image
File photo
As it flares out of the distant Oort Cloud, the newly discovered comet C/2012 S1 (ISON) appears to be heading on a trajectory that could make for one of the most spectacular night-sky events in living memory. Why is this comet expected to be so unique? Two reasons:

Astronomers predict that the comet will pass just 1.16 million miles from the Sun as it swings around its perihelion, or closest approach. (This may seem like a lot, but remember - the Sun is big. If we were to scale the Sun down to the size of Earth, the comet would pass well within the orbits of dozens of satellites.) The close approach will melt enormous amounts of the comet's ice, releasing dust and gas and forming what should be a magnificent tail.

After it loops around the Sun and forms this tail, the comet should then pass relatively close to Earth - not near enough to cause any worry, but close enough to put on a great show. Viewers in the Northern Hemisphere will get the best view as the comet blooms in the weeks approaching Christmas 2013. The comet could grow as bright as the full moon.

Comment: The good news is that it looks like we are certainly going to get a great show... the bad news is that even if the comet body itself comes nowhere near us, it is only a matter of time before Earth interacts with the enormous quantity of debris it leaves in its wake. The wrath of the gods might once more need to be assuaged, portending a bad day for the Powers That Be.

Here is the full text of the 1680 comet description quoted above:
The Dutch and Quaker Colonies in America by John Fiske

Chapter XI, 'New York in the Year 1680'

Late in the autumn of 1680 the good people of Manhattan were overcome with terror at a sight in the heavens such as has seldom greeted human eyes. An enormous comet, perhaps the most magnificent one on record, suddenly made its appearance. At first it was tailless and dim, like a nebulous cloud, but at the end of a week the tail began to show itself and in a second week had attained a length of 30 degrees; in the third week it extended to 70 degrees, while the whole mass was growing brighter. After five weeks it seemed to be absorbed into the intense glare of the sun, but in four days more it reappeared like a blazing sun itself in the throes of some giant convulsion and threw out a tail in the opposite direction as far as the whole distance between the sun and the earth. Sir Isaac Newton, who was then at work upon the mighty problems soon to be published to the world in his Principia, welcomed this strange visitor as affording him a beautiful instance for testing the truth of his new theory of gravitation. But most people throughout the civilized world, the learned as well as the multitude, feared that the end of all things was at hand. Every church in Europe, from the grandest cathedral to the humblest chapel, resounded with supplications, and in the province of New York a day of fasting and humiliation was appointed,in order that the wrath of God might be assuaged.
Astronomy Now's choice of words is interesting... A re-examination of history in light of cyclic catastrophes reveals "once-in-a-civilization" events to be such because they are civilization-ending events!

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Meteor

Comet C/2012 S1 (ISON) - Update 2012, Oct. 4

Nick Howes, Giovanni Sostero and Ernesto Guido
Remanzacco Observatory
Fri, 05 Oct 2012 14:34 UTC
We obtained further follow-up on C/2012 S1 (ISON) on 2012, Oct. 4.6, again through the 2.0-m f/10.0 Ritchey-Chretien + CCD + Bessel R filter of Faulkes Telescope North (F65) Haleakala.

Stacking of 9 exposures, 120 seconds each, produced an image where a well developed and elongated coma measuring nearly 6"x9" is now visible, extended toward PA 280 deg.
Comet ISON
© Remanzacco Observatory
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Meteor

Follow-up on Comet 168P/Hergenrother bright phase

Giovanni Sostero, Nick Howes, Alison Trip and Ernesto Guido
Remanzacco Observatory
Thu, 04 Oct 2012 14:28 UTC
According to reports issued by a number of observers to several astro-forums, comet 168P/Hergenrother is currently experiencing a bright phase: over the course of several nights, it increased in brightness by several magnitudes, reaching a total visual magnitude of approximately 8. We performed some follow-up on it remotely, on 2012 Sept. 26 and Oct. 3, through the 2.0-m f/10.0 Ritchey-Chretien + CCD + Bessel R filter of the Faulkes Telescope South, at Siding Spring.
Comet 168/Hergenrother
© Remanzacco Observatory
Inspecting our stacked images obtained on Sept. 26, the comet shows an obvious central condensation, measuring nearly 3" across; the total coma was traced to a diameter of about 1.7'. On Oct. 3, the central condensation grew to 8" and the total coma diameter was nearly 3'. It's interesting to notice how, apart the growing of the central condensation size, also its appearance changed, appearing pretty sharp on Sept. 26, and a bit "fluffy" on Oct. 3.
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Meteor

Updated data for comet C/2012 S1 (ISON)

Giovanni Sostero, Nick Howes and Ernesto Guido
Remanzacco Observatory
Mon, 01 Oct 2012 13:02 UTC
Our team performed follow-up observations of comet C/2012 S1 (ISON) on 2012, Sept. 28.6, remotely through the 2m, f/10 Ritchey-Chretien + CCD of Faulkes Telescope North (Haleakala) under good seeing conditions, and a scale of 0.3"/px. After stacking 13 R-filtered exposures, 120-seconds each, comet ISON appears as a pale blob of light, slightly elongated toward the south-west (this is particularly obvious looking at the azimuthal median subtraction rendition). Click on the image below to see a bigger version.
Comet C/2012 S1
© Remanzacco Observatory
The Afrho (proxy of dust abundance within the coma) calculation we performed on this dataset, using a few Tycho reference stars having colour indexes close to that of the Sun, provided rather puzzling results: in short, we found a significant variation of the Afrho amount, according to the dimension of the measurement window (something pretty different from the steady state coma model).
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Meteor

Best of the Web: Electric Comet: The Elephant in NASA's Living Room?

Michael Goodspeed
thunderbolts.info
Wed, 29 Jun 2011 00:00 UTC
Image
Left: Specimen produced in the laboratory of CJ Ransom.
Right: Comet Hartley.

For thousands of years, the appearance of a comet in the terrestrial skies has provoked deep anxiety and even collective hysteria in humans the world over. The reasons for this response are not entirely clear. Working with historical testimony, David Talbott and his colleagues have concluded that comet fears originated in a global experience of catastrophe and terror. Behind all of the regional traditions and stories is the memory of the "Great Comet," the mother of all comets. The memory traces to the origins of world mythology, according to Talbott, and is particularly vivid in the story of a cosmic serpent or dragon threatening to destroy the world. The most common ancient ideas attached to a comet were the death of kings, the fall of kingdoms, cosmic upheaval, and the end of the world.

It is well worth asking why this collective anxiety can be provoked with the first appearance of a mere wisp of gas in the heavens. The question is especially appropriate today because of the approach of the Comet Elenin, which is predicted to pass within about 0.233 AU of the Earth in October of this year. Speculations about Elenin range from a theoretical NASA coverup of an "extinction level event," to theories that the comet is actually the ever-elusive planet "Nibiru" of author Zecharia Sitchin's lore. (For a thoughtful meditation on the credibility of some of these theories, see the Subversify.com piece, "Is Google Censoring Nibiru?"). It should be noted here that the leading proponent of the electric universe, Wal Thornhill, has refrained from predicting specific behaviors of Elenin due to the number of unknowns. These unknowns (discussed below) include the Sun's activity, and the constituent material of the comet itself.
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