Yes, it's an asteroid called 99942 Apophis (had to look that one up, in fact...it's the 1st google result) and it will pass earth in 2029. Some doomsday people are worried that it's going to hit us..are you one of them perhaps? If so please have a read on wikipedia

edit: I apologise, I read this again and now I see I completely misread your question. I'll be quiet now

Apparently some, at least one, thinks so, if this site is to be believed: COMET IMPACT PREDICTIONS.

But, since it appears to use fragments from the Holy Bible, postulates about space aliens, bible codes, psychic mediums, Nostradamus and Nostradamus-like prophecies, and other droolworthy claims to support the hypothesis, believing the site just isn't very easy for anyone skeptical in the slightest degree.

Have you run into better evidence for a 1500-year period? Where did you get the value of 1500 years?

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A while ago I ran across this article on a meteor impact in the Indian Ocean (May 2807 BC). When I looked at Solanki’s historical sunspot record I was surprised to see it possibility showed up in the record. The estimated sunspots at this date take a big dip. I thought at the time if the 2 were connected it must be because of the tremendous amount of water vapor ejected into the atmosphere and thus blocking out or reflecting the sun. I just filed it under “curious things.”

Then I ran across the theory that the Younger Dryas cooling was caused by a comet exploding over Canada.

So I went looking for more meteor/ comet impacts in the last 15,000 years. The major one that I found was in the Sargasso Sea 31N 65W and dated at 12,000 BP. This lines up with a huge dip in the sunspot record.

Another was in Argentina 34S 69W dated 10,000 BC and left an impact crater 600 meters across. This lines up with the 8.2 kiloyear event. However this does not hit an ocean. It could have split in 2 and part of it hit the ocean?

Now I am the first to admit that this is very scanty evidence to suggest that all of the wholes in the sunspot record are caused by meteors and comets impacting the earth, however, if they hit the ocean, then they are not going to leave much of a trace.

I have also been reading about Dansgaard-Oeschger events. Stefan Rahmstorf published a paper”Timing of abrupt climate change: A precise clock” In this paper he says the DO events occur every 1,470 years. This type of regularity suggests something extraterrestrial in nature. Could it be something as simple as an asteroid field?

The black diamonds show the timing of Bond cooling events.

I'm not aware of a "special" regio Earth crosses every 1470 years .
As Earth orbits the sun every year I would expect a yearly cycle .
There are some theories the activity of our sun may be involved :
http://www.uni-heidelberg.de/press/n...5/2511ice.html

In addition : I looked which long period comets are known . Most of them are short period comets . The longest period I find in the list is the comet 153P/2002 having a period of 364 years .
http://pdssbn.astro.umd.edu/comet_da...ic_comets.html
Concerning the asteroids : the NEA database shows that the near earth asteroid 1999X535 has a period of 74 years . No asteroids are known with longer periods .
So I don't get any link to bodies appearing or colliding with the given period of time .
Of course as the latest impact out of your diagram is already a good while ago , these bodies may exist but out of our detectable range as they may be now residing far away and out of our optical reach .

If such bodies exist they must have a semi-major axis of about 130 AU , far beyond Pluto's orbit , giving a period of ca. 1480 years .

Finally , one might also think having a (not yet detected - and therefor hypothetical ) disturbing planet in our solar system having a period of 1450 years ( also 130 AU SMA) which brings it twice through the Kuiper belt per revolution. This body could scatter the KBO ,throwing them into orbit towards the sun . Problem with this hypothesis is that the scattered objects fly off in every direction and soon loose their orbital characteristics concerning their period. They would arrive at Earth at "random " intervals....

I came across another asteroid impact in the ocean. It is called the Mahuika crater and occurred in 1443 A.D. Interestingly the impact date lines up with another hole in the graph of historical sunspots.

I’ve read several different people who have asked the question “How do you explain the lack of sunspots during the Maunder Minimum?” The impacts do not explain the lack of sunspots during the Maunder Minimum but, the graph clearly shows an ~7000 year cycle in the sunspot record. This would explain the Maunder Minimum.—A little off topic.

This record of DO events goes back 50,000 years. A very strong indication that they are extra terrestrial in nature. Is it possible that the barycenter cycle has anything to do with stuff getting kicked out of the Oort belt?

Wikipedia has this to say:” The Oort cloud is believed to be a vast shell surrounding our solar system, possibly over a light-year in radius. Across such a vast distance, the gradient of the Milky Way's gravitational field plays a far more noticeable role. Because of this gradient, galactic tides may then deform an otherwise spherical Oort cloud, stretching the cloud in the direction of the galactic centre and compressing it along the other two axes, just as the Earth distends in response to the gravity of the Moon.
The Sun's gravity is sufficiently weak at such a distance that these small galactic perturbations may be enough to dislodge some planetesimals from such distant orbits, sending them towards the Sun and planets by significantly reducing their perihelion.[8] Such a body, being composed of a rock and ice mixture, would become a comet when subjected to the increased solar radiation present in the inner solar system.

I would think that any oscillation coming from the Milky Way would be in millions of years

And the major axis would be 260 AU--so that it would spend a lot of its time 5 times farther than Pluto ever gets--Pluto is now around 30 AU, but will go out near 50 AU.

Jim , when should the next maximum , minumum be according to your shedule ?

Jim,
The comet field information you seek, I think, can be found in the article "An Exceptional Cosmic Influence..." by astrophysicist Victor Clube, published in Fred Hoyle's Universe, eds Wickramasinghe, Burbidge, Narlikar. As this is not an easy text to find even in major libraries, the thesis (a product of decades of work by Clube and Bill Napier) is essentially that the Taurid Complex results from the successive breakups of a massive comet, Proto-Encke. One of the orbital resonance periods of this material, Clube calculates, is 1470 years. He relates this causally to the Bond cycle: (quoting from the article) "the Earth will have experienced sequences of close encounters with dense regions of the meteor stream in the vicinity of the giant comet itself and in the vicinity of its resonant swarm of debris, respectively during one or other nodal intersection at regular intervals of 1/2P(omega) = 2520 years and successive approaches to the Earth's orbit by the libration centre at intervals in the region [long parametric equation not easy to type here] = 1470 years. The Earth will evidently undergo massive inputs of debris and dust at the frequencies of those intervals resulting in corresponding patterns of climatological change during the Upper Pleist. and Holocene" (cf. several Bond articles). The argument is persuasive. I have all relevant articles and references to the 1470 year cycle and related cometary cause.

If you're using the first date to establish baseline, that'd be within five years, right?

Jim,
Quoting Clube on the original massive proto-comet: "we are dealing with a once very large comet (radius ca. 100 km) which has now degenerated into a virtually defunct cometary asteroid [i.e., no longer outgassing comet, ergo difficult to detect, with extremely low albedo--DA] (radiius ca. 10-20 Km, say) accompanied by a family of substantial meteoroids." Tunguska is definitely included in this "family."
Dating occurs on approx. 1470-1500 yr periodicity, with a minor subperiod of events at ca. 725-750 yr detectable in more recent historical millenia due to wider data sources.
Well-established (by several reliable sources, references available) dust-fog (of probable extraterrestrial origin) induced climatic-downturn events, determined by climate proxies, are approximately datable as:
10900-11000 BCE
9500-9600 BCE--ca. 1500 yr interval
7545-7650 BCE--only anomaly in list, 2000-yr interval
6100 BCE--1500-yr
3195 BCE and possibly 3114--2900 yr interval; no record anywhere yet of "missing" event
2354 BCE and probable previous multiple events (most dynamic millenium-probable additional cometary fragmentation period)--ca. 800-yr subperiod
1628 BCE--725 yr interval
1159 BCE and further activity throughout Bronze dark ages to 900 BCE--second most active period of breakup
204 BCE--1420 yr from previous major cycle event
540 CE--745 yr interval (Classical dark age)
1294-1348 multiple events, further breakup period--ca 750 yr interval
??? 725-750 yr subperiod interval means anytime now. Tunguska would likely have represented the first shot across the bow; but note that the remnants of the massive proto-comet are now of substantially reduced size, and there is less expectation of the major dramas that tormented the Bronze and Iron ages. But we are also more vulnerable now to cosmic interferences.