So we can say that the time it would take for such an object from the Oort cloud to reach earth can lay anywhere between at most 2609 years and at least 43 years. Go figure! If they can travel slower or faster, the estimates in both direction can increase even further, in both directions. So any number in between the two given above can hold true for any given object or swarms of them in terms of how long it takes for them to reach earth.
Glad to see I'm not the only one crunching these bones.
The speed of the super fast comet is impressive. 600 km/s is 30 times faster than the Chelyabinsk meteor, which gives 900 times more energy per unit of mass. The Chelyabinsk meteor was a minimum of 10,000 tons up to14,000 tons so this would mean that the same amount of destruction would be created by just 11-15 tons.
Now building on some of your ideas, I will try a more classical approach and find out where it leads. How far out do the comets go and how long do they take to get here under normal circumstances?
On
semimajor axis actually the same page from where I found the information about Jonathan Swift
Jonathan Swift and the moons of Mars there was some information that might help to calculate what the usual estimated travel distances and travel times are for comets.
The semimajor axis is half the longest distance (major axis) across an
ellipse. The semimajor axis is one of the
orbital elements – a standard parameter used to describe an elliptical orbit. The semimajor axis is also the average distance of an orbiting object from its primary. The
periapsis and apoapsis distances,
rp and
ra, can be calculated from the semimajor axis,
a, and the eccentricity,
e, by the formula
rp =
a(1 -
e) and
ra =
a(1 +
e)
When looking into the tables known comets the "periapsis" is called perihelion and apoapsis, if it was given would then be aphelion. See
Apsis - Wikipedia
Assuming the laws of Kepler have validity for some of the comets, what might the above mathematics mean if one selects a comet with a known semimajor axis a and know eccentricity e.
For the comets with an orbital periods from 200 to a 1000 years there is a list of periods:
List of long-period comets - Wikipedia They have semimajor axis ranging from 35 AU to just under 100 AU and eccentricities ranging from 0.872862 to 0.999946 The list comes with this introduction:
The following list is of
comets with very long
orbital periods, defined as between 200 and 1000 years.
These comets come from the Kuiper belt and scattered disk, beyond the orbit of Pluto, with possible origins in the Oort cloud for many. For comets with an orbital period of over 1000 years, see the
List of near-parabolic comets.
And in the list of near-parabolic comets they begin:
The following is a list of
comets with a very high
eccentricity (generally 0.99 or higher) and a
period of over 1,000 years that don't quite have a high enough
velocity to escape the
Solar System. Often, these comets, due to their extreme
semimajor axes and eccentricity, will have small orbital interactions with
planets and
minor planets,
most often ending up with the comets fluctuating significantly in their orbital path. These comets probably come from the
Oort cloud, a cloud of comets orbiting the
Sun from ~10,000 to roughly 50,000
AU.
The actual orbit of these comets significantly differs from the provided coordinates. A Solar System
barycentric orbit computed at an
epoch when the object is located beyond all the planets is a more accurate measurement of its long-term orbit.
The further away the more unreliable unless one can calculate their orbit based on observations beyond the planet filled inner solar system, which is perhaps also assuming there are no major disturbances out there.
From
List of near-parabolic comets - Wikipedia I chose three that have estimated periods of 3600 years, considering that perhaps the 3600 year cycle of comet showers has something to do with comets that have a 3600 year period?
C/1990 N1, Semimajor axis: 233,2246 AU, Eccentricity 0,995316, Perihelion 1,092424 AU Orbital period 3560
ra =
a(1 +
e) gives
ra = 233,2246 AU (1+0,995316)=465.357 AU
C/1999 K3 Semimajor axis: 235 AU, Eccentricity 0.9918 Perihelion 1,92878 AU Orbital period 3600
ra =
a(1 +
e) gives
ra = 235 AU (1+0.9918) = 468 AU
C/2004 F4 Semimajor axis 238 AU, Eccentricity 0.999294 Perihelion 0,168266 AU Orbital period 3680
ra =
a(1 +
e) gives
ra = 238 AU (1+0.999294) = 476 AU
Considering what they wrote in the introduction: "
actual orbit of these comets significantly differs from the provided coordinates" the above distances may not be accurate down to the last given digit. However considering the eccentricities for all the long period and near parabolic comets being close to 1, admittedly with more inaccuracy for the long period comets, one can multiply the semimajor axis distance by two and have a good idea of how far out they might go.
When the 3600 period comet have an aphelion of 470 AU and compare this to the C's mentioning the Oort cloud as being in the 5500 AU range on average, then the 3600 year period comet ought to be in those regions of the Oort cloud which are closer to us. Timewise if their period is 3600 years it should, everything else equal take 1800 to go out and 1800 years to come back.
If instead of taking a comet with a given period and finding out how far it is out, we want to find out how long it takes to get out to 5500 AU under normal classical circumstances, then we can take a comet with a semimajor axis of about half of 5500 AU. We know from the previous example, that if we multiply a semimajor axis by two we would get out as far as it would go. In this case twice 2750 AU would be 5500 AU, which would take us right in the average area of the Oort Cloud. If we can find a few of such comets, we could look up and find out how long the orbital periods. This
List of near-parabolic comets - Wikipedia informs us that there are several candidates, below are four which are close to the distance we are looking for.
Name Semimajor axis Eccentricity Orbital period
C/2013 G5 2700 0.99965 140000
C/1999 H1 2775 0.9997449 146200
C/2011 F1 2780 0.999345 146000
C/1916 G1 2834.363 0.999405 150900
A semimajor axis of 2700 AU would give a max distance to the Sun of about 5400 AU
A semimajor axis of 2834.363 AU would give a max distance to the Sun of about 5660 AU
As the orbital periods are 140,000 -150,000 years it would take something like 70,000 to 75,000 years to move from the extreme position in the average distance of the Oort Cloud to the position near the Sun - under the expected conditions, and that could be where the error may come in, because there are other influences:
August 3, 1996
Session 3 August 1996
A: Everything reflects macrodynamically and microdynamically. We suggest you absorb for now; and, fear not! For it is not imminent! Good Night.
July 4, 1998 Frank, Ark, Laura. Q: Hello. A: Hello. Q: And who do we have with us this evening? A: Higurrah. Q: And where do you transmit through? A: Cassiopaea. Q: (A) I am trying to write down some things about a cosmology, and I have some questions mainly about the coming...
cassiopaea.org
A: Disasters involve cycles in the human experiential cycle which corresponds to the passage of comet cluster.
[...]
A: Did you catch the significance of the answer regarding time table of cluster and brown star? Human cycle mirrors cycle of catastrophe. Earth benefits in form of periodic cleansing. Time to start paying attention to the signs. They are escalating. They can even be “felt” by you and others, if you pay attention.
Not imminent was in 1996, 23 years ago. In 1998 it was: "They are escalating. They can even be “felt” by you and others, if you pay attention." And now we are in the middle of something, aren't we?