Comets


Comet 2

Could a comet hit Mars in 2014?

Ian O'Neill
Discovery News
Mon, 25 Feb 2013 12:12 UTC
Cometary Nucleus
© NASAArtist’s impression of a cometary nucleus.
A recently discovered comet will make an uncomfortably-close planetary flyby next year - but this time it's not Earth that's in the cosmic crosshairs.

According to preliminary orbital prediction models, comet C/2013 A1 will buzz Mars on Oct. 19, 2014. The icy interloper is thought to originate from the Oort Cloud - a hypothetical region surrounding the solar system containing countless billions of cometary nuclei that were outcast from the primordial solar system billions of years ago.

We know that the planets have been hit by comets before (re: the massive Comet Shoemaker - Levy 9 that crashed into Jupiter in 1994) and Mars, in particular, will have been hit by comets in the past. It's believed Earth's oceans were created by water delivered by comets - cometary impacts are an inevitable part of living in this cosmic ecosystem.

C/2013 A1 was discovered by ace comet-hunter Robert McNaught at the Siding Spring Observatory in New South Wales, Australia, on Jan. 3. When the discovery was made, astronomers at the Catalina Sky Survey in Arizona looked back over their observations to find "prerecovery" images of the comet dating back to Dec. 8, 2012. These observations placed the orbital trajectory of comet C/2013 A1 through Mars orbit on Oct. 19, 2014.

Could the Red Planet be in for a potentially huge impact next year? Will Mars rovers Curiosity and Opportunity be in danger of becoming scrap metal?

Comment: Perhaps we should be looking a bit closer to home? There's been a dramatic increase of fireballs around the planet in the last few days. For more information about what might be coming down the pike in the near future read: Comets and the Horns of Moses by Laura Knight-Jadczyk.

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Camera

Noctilucent clouds appear out of season and far to the south - cometary dust from the Russian meteor blast?


Sott.net
Mon, 25 Feb 2013 06:28 UTC
From 19-21 February 2013, noctilucent clouds were observed in the UK, Denmark, Norway and the Netherlands. Since these clouds are usually only seen in summer, it is suspected that they may be the result of comet dust deposited in the upper atmosphere by the Chelyabinsk/Chebarkul meteor or comet fragment explosion over Southern Russia on 15 February.

The following images were submitted to spaceweather.com
Image
© Terry ParkerImage taken by Terry Parker on Feb. 20, 2013 from above Birmingham, UK. 'I am an airline pilot in the UK and I occasionally see noctilucent clouds. Usually during the summer at about midnight looking North. But yesterday (20 Feb 13) I was very surprised to see them looking south towards France and so close to sunrise.'

Image
© Tom AxelsenPhoto by Tom Axelsen, Copenhagen area, Denmark
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Comet 2

New Comet: C/2013 C2 (Tenagra)

Seiichi Yoshida
Aerith Net
Sat, 23 Feb 2013 15:33 UTC
Discovery Date: February 14, 2013

Magnitude: 19.0 mag

Discoverer: P. R. Holvorcem, M. Schwartz (Tenagra Observatory)

C/2013 C2 (Tenagra)
© Aerith Net
The orbital elements are published on M.P.E.C. 2013-D22.
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Comet

New Comet: P/2013 CE31 (MOSS)

Seiichi Yoshida
Aerith Net
Sat, 23 Feb 2013 15:25 UTC
Discovery Date: February 5, 2013

Magnitude: 20.3 mag

Discoverer: Claudine Rinner (Morocco Oukaimeden Sky Survey)

P/2013 CE31
© Aerith Net
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Comet 2

New Comet: C/2013 D1 (Holvorcem)

Seiichi Yoshida
Aerith Net
Sat, 23 Feb 2013 15:20 UTC
Discovery Date: February 16, 2013

Magnitude: 19.2 mag

Discoverer: Paulo Holvorcem (Tenagra III astrograph)

C/2013 D1
© Aerith NetMagnitude graph.
The orbital elements are published on M.P.E.C. 2013-D41.
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Comet

When asteroids become comets: Both are fundamentally the same


Thunderbolts.info
Fri, 07 Apr 2006 06:42 UTC
Image
© Pedro Lacerda (Univ. Hawaii; Univ. Coimbra, PortugalOrbits of the three known main-belt comets (red lines), the five innermost planets (black lines; from the center outward: Mercury, Venus, Earth, Mars, and Jupiter), a sample of 100 main-belt asteroids (orange lines), and two "typical" comets (Halley's Comet, and Tempel 1, target of the recent Deep Impact mission) as blue lines. Positions of the main-belt comets and planets on March 1, 2006, are plotted with black dots.
The surprising discovery of asteroids with comet tails supports the longstanding claim of the electrical theorists - that the essential difference between asteroids and comets is the shape of their orbits.

According to a recent story in USA Today, astronomers are "rethinking long-held beliefs about the distant domains of comets and asteroids, abodes they've always considered light-years apart". The discovery has forced astronomers to speculate that some asteroids are actually "dirty snowballs in disguise".

For many years the standard view of asteroids asserted that they are composed of dust, rock, and metal and that most occupy a belt between Mars and Jupiter. In contrast, comets were claimed to arrive from a home in deep space, most coming from an imagined "Oort Cloud" at the outermost reaches of the solar system, where they are supposed to have accreted from leftover dust and ices from the formation of the solar system.

But now, "the locales of comets and asteroids may not be such a key distinction", states Dan Vergano, reporting on the work of two University of Hawaii astronomers, Henry Hsieh and David Jewitt. In a survey of 300 asteroids lurking in the asteroid belt, the astronomers detected three objects that "look a lot like comets ... ejecting little comet tails at times from their surfaces". The three red circles in the illustration above describe the orbits of these bodies.
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Fireball 2

Chelyabinsk meteor explosion in pictures: Videos and photos from Russia

Alexander Zaytsev
say26.com
Wed, 20 Feb 2013 11:14 UTC
I happen to live 300kms away from Chelyabinsk, where a large bolide exploded earlier today. Here are all the videos I could find featuring the massive explosion and its effects.

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Comet 2

Russian meteor: Hunt for debris begins, but was it a comet?


The Extinction Protocol
Wed, 20 Feb 2013 07:32 UTC
A race for cosmic souvenirs has begun after scientists said there were still many pieces of the meteorite that fell to earth near the Russian city of Chelyabinsk last week waiting to be found. The extraterrestrial origin of 53 rock fragments collected on the frozen surface of Lake Chebarkul was confirmed during analysis conducted by the Urals Federal University in the early hours of Monday. But this is just the start of the process of gathering the debris left by the large meteorite, which exploded on entering the earth's atmosphere and hit the ground in a series of fireballs on Friday. Viktor Grokhovsky, a member of the Russian Academy of Science's meteorite committee, has been put in charge of the scientific search operation. "There are a lot more fragments to be discovered in many other places ... it's only a matter of time," he said.

The search is being concentrated at the moment around a six-metre wide hole in Lake Chebarkul, about 50 miles from Chelyabinsk, discovered by locals shortly after the meteorite hit the ground. Military divers spent much of the weekend scouring the bottom of the lake, but were hampered by poor visibility and found nothing. Analysis of the pieces recovered so far, none of which had a diameter greater than 1cm, suggests that 10% of the meteorite was made up of iron. Traces of sulphite and the mineral olivine were also present. "It was a stone meteorite that belongs to a class of ordinary chondrite meteorites," said Grokhovsky.

Link to video: Russian meteorite: first fragment finds claimed
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Comet 2

Shoemaker-Levy 9: Comet's impact left its mark on Jupiter

Elizabeth Howell
SPACE.com
Tue, 19 Feb 2013 16:00 UTC
Comet Shoemaker-Levy 9 experienced one of the most spectacular ends that humans ever witnessed. Several months after its discovery, pieces of the comet smashed into the planet Jupiter. The collision produced scars that were visible from Earth in small telescopes.

"This is the first collision of two solar system bodies ever to be observed, and the effects of the comet impacts on Jupiter's atmosphere have been simply spectacular and beyond expectations," NASA wrote on a website describing the comet.
Image
© JPL/NASA/STScIJupiter vacuumed up the pieces of the disrupted comet Shoemaker–Levy 9 in 1994, but the impacts were a reminder of the danger faced by Earth.
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Fireball 5

The year of the comets: Three reasons why 2013 could be the best ever

Bob King
Universe Today
Tue, 19 Feb 2013 11:47 UTC
L4 Panstarrs
© Joseph BrimacombeComet L4 Panstarrs photographed from Australia at dawn on Feb. 17, 2013 with a telephoto lens. A bright head and short tail are visible.
2013 could turn out to be a comet bonanza. No fewer than three of these long-tailed beauties are expected to brighten to naked eye visibility. Already Comet C/2011 L4 PANSTARRS has cracked that barrier. Sky watchers in Australia have watched it grow from a telescopic smudge to a beautiful binocular sight low above the horizon at both dusk and dawn. A few have even spotted it without optical aid in the past week. Excited reports of a bright, fan-shaped dust tail two full moon diameters long whet our appetite for what's to come.

Recent brightness estimates indicate that the comet could be experiencing a surge or "second wind" after plateauing in brightness the past few weeks. If the current trend continues, PanSTARRS might reach 1st or 2nd magnitude or a little brighter than the stars of the Big Dipper when it first becomes visible to northern hemisphere sky watchers around March 7. That's little more than two weeks away!
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