No.
If the fall was seen by enough observers the orbit can be calculated. All orbits for falls, and all orbits for meteors are all of solar system objects. No hyperbolic orbits (those from outside the solar system have been found for any comet. Some comets have orbits that are calculated as parabolic and "potentially: extrasolar. However, thes parabolic orbits are just an easy approximation to very long period orbits.
Also the compostion of meteorites, matches known compostions within our solar system. For example, Martian meteorites have tiny gas bubbles with the same compostion as the Martian atmosphere including argon content.
Thanks! I can see why it is difficult to determine extrasolar trajectories from the limited data that come from orbit observations. Do you - or others - have some ideas of reasonable bounds on the numbers of extrasolar macrossopic bodies that might be put into solar orbits on any reasonable time scale, by extrasolar ejection events? Maybe there is some virial theorem/collision impact argument that makes this most improbable?
Some isotopic anomalies found in some meteorites could sign two disparate stellar sources. I wonder if this could also give some indications about a putative origin of a meteorite outside the Solar System.
See also the following article
https://www.oca.eu/morby/papers/Comet-Mets.pdf
Please don't mix the concepts. Stefan was absolutely right. Meteorites are generally produced by meter-sized meteoroids whose heliocentric orbits can be computed from their luminous phases (fireballs or bolides). There is no evidence for even mm-sized meteoroids exhibiting hyperbolic orbits. Only going to micron-sized grains, radiotelescopes like e.g. Arecibo detect interstellar grains that are originated in the outer envolopes of other stars. This paper can be considered an excellent review in that regard:
http://meteor.uwo.ca/cmor_pub/CMOR_interstellar_paper_EMP.pdf
Particularly the section 2 put you in the progress made recently in different lines of research concerning your question. Summarizing, there are tiny particles of interstellar origin reaching the Solar System from the outer space but not large meteoroids. Much less we should expect meteorites, because their extremely high incoming velocities. Just their required tensile strengths should be extraordinarily high to survive atmospheric ablation. Visit my homepage for more details and publications on meteoroid orbits, and their sources: http://www.spmn.uji.es/ESP/trigopap.html
Interstellar micro-meteorites are detected by the AMOR system in New Zealand (University of Canterbury). That radar has been operational for several decades and allows estimation of the particle orbits. AMOR has identified two inter-stellar dust streams (based on their hyperbolic orbits) and one appears to be related to the star beta Pictoris.
See: http://www.phys.canterbury.ac.nz/research/birdlings.shtml
Check the publications of W. Jack Baggaley who established the AMOR system for the details.
There is no interstellar meteor! Other planetary systems can produce icy particles only; solar heating will evaporate them before they come close to the Earth. In the interstellar media only sub-micron refractory particles can exist, and they could produce radio-meteors, but very rarely, because solar radiation pressure should decelerate them and push them away from the Solar system. Most of so-called "interstellar radio meteors" are the particles from solar system meteors, that were accelerated by Jupiter or the rest giant planets.
despite it is very difficult to find an "alien"-meteorite, I would not esclude 100% that noone could come far out ("alien") the Solar System. They discover recently planets that travel alones through the galaxy, stars going out too, see also here http://www.dailygalaxy.com/my_weblog/2012/03/-warp-speed-planets-escaping-milky-way-at-30-million-mph-1.html and here http://news.discovery.com/space/alien-life-exoplanets/orphan-planet-121114.htm, so I wonder why not asteroids...
Alexander, please use the terminology "meteoroid" for these particles in space. In reference with your comment, stellar grains are produced in the circumstellar environments of evolved stars. Many are refractory and could be larger than a micron as we find in primitive chondrites. Some of these particles are in the size range of the small meteoroids detected by radar systems. However, I agree that an important contribution can be produced by solar system processes. On the other hand, interstellar asteroids and comets have not been observed so far. Comets following eccentric orbits are associated with the Oort cloud, still in the border of the Sun's gravity field. Perhaps the mechanisms to inject these bodies in interstellar routes are preferentially destroying them.
What a range of interesting comments on my naive question! Thanks to all - you have sharpened my understanding and interest in the matter.
Dear colleagues!
My answer attracted your attention because it contradicts some widely adopted ideas. I am ready to point to the main weak basic conceptions.
1. The “Standard Cosmogony” bases on idea that all matter in the Solar system origin from interstellar dust-gaseous nebula. It is correct, bur the interstellar gaseous nebulae contain only primordial hydrogen and helium. This gas is very hot, and it practically cannot cool by itself. When supernovae explode they add to the clouds heavy elements in forms of dust particles and molecules. Some heavy elements just in the same forms are added by star wind from late classes. Since these gases are rapidly cooling, so they can collapse into stars and planets. Please pay attention to the fact that there could not be large refractory particles (like meteorites)! All primordial planetesimales have to be snowballs of different sizes. So the idea that primitive chondrites were in the proto-planetary disc seems to be noncense.
The Standard Cosmogony closes eyes on the origin of refractory pieces inside comet nuclei, though astronomers are sure that after comet nucleus lost its volatiles there are lots of such particles on the orbit of former comet. When they meet the Earth atmosphere, they produce meteors (shooting stars). These particles cannot be icy ones; otherwise they would be evaporated in few seconds. Really, meteor streams live thousands years. The Standard Cosmogony cannot explain this fact, as due to the theory comet nuclei consist of the primordial matter that was free of heavy refractory particles.
This is why interstellar comets cannot produce meteors at all except of pebbles ones, that can (?) produce radio-meteors.
2. The same Standard Cosmogony claims that asteroid of the Main Belt are remnants of primordial planetesimales that were not allowed to heap into whole planet between Mars and Jupiter. If so, why asteroids are believed to be solid bodies of meteorite material or, at least, rubble piles? Meteorites are known to be very different – irony, stone or composite. This means that material of asteroids has to be initially concentrated in a body large enough to be melted by radioactive 26Al and to be differentiated inside it. Later this body has to be destroyed anyway to produce asteroids. To avoid problems with destruction of as large body as our Moon, the Standard Theory claims that there were some large bodies that collides and destroy themselves. Why nobody try to calculate the kinetic energy of two moon-size bodies at velocity about 20 km/s? It is not enough to free rubbles after collision…
So a conclusion from the Standard Theory can be one: it cannot explain asteroids origin as well as promises that asteroids can be members of the other planetary systems.
On the other hand, the ordinal comet nucleuses can slowly losses volatiles from its surface, say, by stellar or solar radiation. Numerous dust particles will rest on the nucleus surface and produce porous shell over it. This shell will look very dark (albedo ~ 1%). The whole body will behave as ordinal dark asteroid, but it will remain comet nucleus.
When astrophysics discovers “asteroid belts” around alien stars, they mean that they observe bodies that disperse light like “blackbodies” and nothing more. In a common case they are primordial planetesimales (comet nuclei of various sizes). Surely, some of them can escape parent star and reach the Solar system, but they are not asteroids and they cannot produce meteors.
3. Mattia Galiazzo pointed internet publications (http://www.dailygalaxy.com/my_weblog/2012/03/-warp-speed-planets-escaping-milky-way-at-30-million-mph-1.html and http://news.discovery.com/space/alien-life-exoplanets/orphan-planet-121114.htm), that concerns Free-Floating Orphan Planet. Of course such planets have to be numerous in our Galaxy, but their velocities cannot be so large as it discussed in first publication. To obtain velocity even about 250 km/s the planet must come to a black hole (or any star) so close that it would be blown up by tidal forces. I think that velocities of such “interstellar striders” will be up to 100 km/s. I cannot agree with my colleague Josep Trigo-Rodríguez that suppose planetesimales not to survive injection into interstellar space.
The escaped planets seem to be the more numerous the fewer dimensions they are. I suppose that there are at least 1000 moon-size planets to each star of the Galaxy. As for 1-km sized planetesimales, they have to cross internal part of our Solar system (inside Jupiter’s orbit) every 10 years. They are hard to detect as they are extremely dark and move fast. Nevertheless I believe that such objects will be discovered soon.
4. If we adopt the idea of interstellar striders, why not to suppose that one of them had collided long ago a Solar system planet and disperse it into billions fragments? Some of them could reach outer parts of planetary system; heap snowflakes of the primordial proto-planetary disc and produce “planetesimales of the second generation”. They will be just the common comet nuclei but have inclusions of moldings from destroyed planet. This explains well the connection between comets and meteor streams. On the other hand, this scenario may be very, very rear for alien planetary systems, so meteorite particles seems not to be outside our Solar system.
Dear colleagues!
My answer attracted your attention because it contradicts some widely adopted ideas. I am ready to point to the main weak basic conceptions.
1. The “Standard Cosmogony” bases on idea that all matter in the Solar system origin from interstellar dust-gaseous nebula. It is correct, bur the interstellar gaseous nebulae contain only primordial hydrogen and helium. This gas is very hot, and it practically cannot cool by itself. When supernovae explode they add to the clouds heavy elements in forms of dust particles and molecules. Some heavy elements just in the same forms are added by star wind from late classes. Since these gases are rapidly cooling, so they can collapse into stars and planets. Please pay attention to the fact that there could not be large refractory particles (like meteorites)! All primordial planetesimales have to be snowballs of different sizes. So the idea that primitive chondrites were in the proto-planetary disc seems to be noncense.
The Standard Cosmogony closes eyes on the origin of refractory pieces inside comet nuclei, though astronomers are sure that after comet nucleus lost its volatiles there are lots of such particles on the orbit of former comet. When they meet the Earth atmosphere, they produce meteors (shooting stars). These particles cannot be icy ones; otherwise they would be evaporated in few seconds. Really, meteor streams live thousands years. The Standard Cosmogony cannot explain this fact, as due to the theory comet nuclei consist of the primordial matter that was free of heavy refractory particles.
This is why interstellar comets cannot produce meteors at all except of pebbles ones, that can (?) produce radio-meteors.
2. The same Standard Cosmogony claims that asteroid of the Main Belt are remnants of primordial planetesimales that were not allowed to heap into whole planet between Mars and Jupiter. If so, why asteroids are believed to be solid bodies of meteorite material or, at least, rubble piles? Meteorites are known to be very different – irony, stone or composite. This means that material of asteroids has to be initially concentrated in a body large enough to be melted by radioactive 26Al and to be differentiated inside it. Later this body has to be destroyed anyway to produce asteroids. To avoid problems with destruction of as large body as our Moon, the Standard Theory claims that there were some large bodies that collides and destroy themselves. Why nobody try to calculate the kinetic energy of two moon-size bodies at velocity about 20 km/s? It is not enough to free rubbles after collision…
So a conclusion from the Standard Theory can be one: it cannot explain asteroids origin as well as promises that asteroids can be members of the other planetary systems.
On the other hand, the ordinal comet nucleuses can slowly losses volatiles from its surface, say, by stellar or solar radiation. Numerous dust particles will rest on the nucleus surface and produce porous shell over it. This shell will look very dark (albedo ~ 1%). The whole body will behave as ordinal dark asteroid, but it will remain comet nucleus.
When astrophysics discovers “asteroid belts” around alien stars, they mean that they observe bodies that disperse light like “blackbodies” and nothing more. In a common case they are primordial planetesimales (comet nuclei of various sizes). Surely, some of them can escape parent star and reach the Solar system, but they are not asteroids and they cannot produce meteors.
3. Mattia Galiazzo pointed internet publications (http://www.dailygalaxy.com/my_weblog/2012/03/-warp-speed-planets-escaping-milky-way-at-30-million-mph-1.html and http://news.discovery.com/space/alien-life-exoplanets/orphan-planet-121114.htm), that concerns Free-Floating Orphan Planet. Of course such planets have to be numerous in our Galaxy, but their velocities cannot be so large as it discussed in first publication. To obtain velocity even about 250 km/s the planet must come to a black hole (or any star) so close that it would be blown up by tidal forces. I think that velocities of such “interstellar striders” will be up to 100 km/s. I cannot agree with my colleague Josep Trigo-Rodríguez that suppose planetesimales not to survive injection into interstellar space.
The escaped planets seem to be the more numerous the fewer dimensions they are. I suppose that there are at least 1000 moon-size planets to each star of the Galaxy. As for 1-km sized planetesimales, they have to cross internal part of our Solar system (inside Jupiter’s orbit) every 10 years. They are hard to detect as they are extremely dark and move fast. Nevertheless I believe that such objects will be discovered soon.
4. If we adopt the idea of interstellar striders, why not to suppose that one of them had collided long ago a Solar system planet and disperse it into billions fragments? Some of them could reach outer parts of planetary system; heap snowflakes of the primordial proto-planetary disc and produce “planetesimales of the second generation”. They will be just the common comet nuclei but have inclusions of moldings from destroyed planet. This explains well the connection between comets and meteor streams. On the other hand, this scenario may be very, very rear for alien planetary systems, so meteorite particles seems not to be outside our Solar system.
Alexander Bagrov writes that a collision of two Lunar-sized bodies will not result in the release of fragments since they will be gravitationally bound. Although this is certainly true - it is not a problem for our understanding of the origin of differentiated meteorites from asteroids. Cooling rates of iron meteorites range from 1-1000 K/My. These cooling rates constrain the cooling rate of the asteroid core shortly after it crystallized. Since largfe asteroids cool slower than small asteroids they may be used to infer sizes of asteroids. Diameters were genererally less than 50 km - much smaller than the Moon - and sufficiently small that it is not a problem to catastrophically destroy them.
We know that fragments of asteroids escape our Solar System and it thus follows that fragments must also escape other Solar System provided they include minor bodies. It should therefore be possible to find an extrasolar rock in our Solar System. Unfortunately, it is unlikely that it will heat our atmosphere slowly enough to survive. Also, the frequency of such a fall makes it unlikely that we will ever observe it or even find an old extrasolar meteorite fall here on Earth. I have seen an estimate concluding that we should expect a extrasolar meteorite fall here on Earth every 10 billion years.
In other words, extrasolar meteorites are not impossible but the exceedingly low fall rates makes it less than likely that we will ever come across one.
If we were ever to find one there is no doubt that we be able to tell that it is extraolar - it would be different in terms of bulk chemistry, isotope chemistry and its ages would be way off anything we have seen before.
When Henning Haack claims that asteroids can collide often, it seems to be mistake. Now we have many arguments that there are more then 15% asteroids that have satellites. The gravitation between two tiny bodies is so negligible, that any collision must break it. As there is no mechanism for asteroids to capture into orbit other bodies, we have to propose that asteroid collisions are extremely rare. Every asteroid has its own orbit, and if they do not cross each other, the collision is absolutely impossible. Trams in Oslo and in London will never collide, as they have not-crossing railways.
Besides that even a tiny meteorite needs enormous energy added to escape our Solar system. Celestial mechanic allows such opportunity, but only in case of its very close passage near large planet (gravitational interaction with asteroid is too weak to produce necessary effect). Is there enough meteorites that approach to Jupiter less then 6…14 its radius? So the number of escaped meteorites would be miserable. Now calculate, what is chance for the meteorite hit a planet which own volume is billion-billion-billion (and so on) times less then volume of interstellar space? Evidently, nearly zero.
As for the Earth, any meteorite will be totally evaporated in atmosphere, if it is less then foot in diameter. Moving with interstellar velocity it may have kinetic energy times above necessary to evaporate it at collision.
So I am sure, there is no possibility to meet any interstellar meteorite.
Answer to Alexander Bagrov:
The impact rate in the asteroid belt (and the inner Solar System) is fairly well constrained - primarily based on Apollo samples from the Moon. The Apollo astronauts sampled the Lunar impact basins. By dating the samples of the impact basins and counting the number of impact craters of different sizes, in the Lunar impact basins, we can obtain the cratering rate of different sized bodies. We also have a good understanding of the km-sized objects in the asteroid belt and this may be used to extrapolate to smaller sizes.
Most meteorites are launched in smaller impacts - simply since small impactors are much more abundant. Nevertheless, we do know of a few very large impacts - such as the one that destroyed the L-chondrite parent body 470 million years ago - and the one that destroyed the IIIAB iron core 650 million years ago. Obviously, you cannot say that these events happen often - but they do happen and the fragments will continue to hit the Earth hundreds of millions of years later. In fact, the IIIAB irons are the most common type of iron meteorites to hit the Earth and the L-chondrites are the most common type of meteorites to hit the Earth.
There are several studies that have looked at the fate of fragmental debris based on computer simulations. Meter-sized fragments will slowly evolve through interactions with the gravity field of planets - including close encounters, but thermal effects, such as the Yarkovsky and YORP effects also play a major role in the orbital evolution. Much of the debris end up in the Sun, part of it is thrown out of the Solar system and the last bit will impact planets, moons and asteroids.
Planetary encounters are, of course, rare - but the orbits evolve gradually over many million years and on that timescale encounters are not un-common.
Speed. If the speed exceeds 70km/sec, this body does not belong to solar system. But as I know, such meteorites did not observe till now.
Igor, when you are talking about "speed" you should always say relative to what. The Solar System escape velocity is about 42.1 km/s, so all bodies moving over this velocity should be interstellar. However, in a head-on collision with Earth of a body moving with about 42 km/s produces a maximum geocentric velocity of 30+42=72 km/s. This geocentric velocity is close to the velocity of Leonid meteoroids (about 70 km/s) reaching the Earth with the orbital geometry close to that of comet 55P/Tempel-Tuttle, their parent comet. Impact geometry also plays an important role, and the heliocentric orbit must to be derived to be 100% sure about their origin. As said before in this bench, David Meisel and collaborators have demonstrated that large radiotelescopes detect micron-sized dust of interstellar origin, but no meteoroids so far as you well said.
Of course, you can take 72 km as more sure estimation, this speed is necessary condition. Such bodies should be interstellar, and beeng observed, the speed could be estimated with necessary precision. Other conditions seems to be not so strong. I can add that in 60-s the hypothesys of meteorites composed of antimatter was investigated by Leningrad's physics(prof.Konstantinov). Very funny, when not specialists get financial support from the goverment. By-product was a large number of radar observations of meteor trails and obtaining new data on ultra-ultra-long radio waves communication.
There is a theory shown in the lower right hand corner of the wall chart:
A CORRELATED HISTORY OF THE EARTH
that indicates that mass extinctions are related to the cyclical exposure of the
Solar System to the various arms of the Milky Way Galaxy.
My conclusion is that " If " our solar system is part of the Sagittarius Galaxy, and
"If " the Sagittarius Galaxy is spinning through the Milky Way Galaxy, then,
it is possible that we ( and all the other planets in the Solar System ) get
impacted by " Space Rocks " from the other Galaxy, in a repeating pattern.
That Pattern cycles every 166 Million Years ( his calculation ), or 166.6 million
years ( My calculation ).
There is a Math error in his cyclical chart where the 52 million year gap is, it should
be 49 million years.
One might be able to create a testable Hypothesis from this by looking at the
material that hits the Earth in each of the 7 exposures per cycle to see if
the material is similar, or different.
Using 186.6 MY as the cycle, the sequence deltas ( differences in time in
millions of years between impact sequences ) is as follows:
D, 34, E, 14, F, 17, G, 49, A , 32, B, 20, C 14 ( NOW ) +6.6 , D , ............
NOTE The time gap from C to D is 20.6 MY, and we are about 2/3 rds
of the way through it.
A ( Crux Arm ) seems to be the big killer ( bigger extinction events):
A "s : 812.4 MYA, 625.8 MYA, 439.2 MYA, 252.6 MYA, 66.0 MYA
B "s: 780.4, 593.8, 407.2, 220.6, 34 MYA
C "s: 760.4, 573.8, 387.2, 200.6, 14 MYA
D "s: 739.8, 553.2, 366.6, 180.0, +6.6 MYF
E "s: 892.4, 705.8, 519.2, 332.6, 146 MYA
F "s: 878.4, 691.8, 505.2, 318.6, 132 MYA
G "s: 861.4, 674.8, 488.2, 301.6, 115 MYA
using a 186.6 MY repeat.
I have multiple copies of the
CORRELATED HISTORY OF THE EARTH
in my home and office.
If you want to know a relationship between two or
more events, and you do not want to spend a
lot of time finding that relationship, a look at the wall
chart will usually suffice.
This is really something that is fun to play with.
For Example, you can use the cyclicity to estimate the
age of planets:
If the Earth is a product of an A collision, then it is
24 ( 186.6 ) + 66 = 4544.40 MY old.
If the Moon is the product of a D collision, then it is
22 ( 186.6 ) + 180 = 4285.20 MY old.
The difference in age is then 4544.40-4285.20 = 259.2 MY
And 252.6 MYA + 6.6 MYF = 259.2 MY.
So 6.6 MYF the Moon will complete its 23 rd Galactic Orbit,
, and be 23 x 186.6 MY = 4291.8 MY old.
The earth will be 24 x 186.6 plus 66 plus 6.6 = 4551 MY old.
Cyclicity could be the key to finding all the planets ages
Food for Thought, and fun to play with if you like numbers.
Well, I blew the first numbers, the 166 and the 166.6 should have been
186 and 186.6.
The 202 MYA and the 230 MYA both got my attention.
The 202 MYA is the Triassic - Jurassic Boundary.
The 230 Million years ago is the same number I used to
model the trigger time for the late exponential growth of the
Earth that formed the current Ocean Basins, and allowed the
water to pour off the continents into the newly forming
ocean basins.
I have been struggling with, what was the maximum elevation
of the water on the planet, but the continents and the oceans have
an annoying habit of changing elevations relative to one another.
The best that I can come up with is that the oceans were at least
10,000 feet higher in Bolivia, because the Salar de Uyuni is is giant
salt flat contained on one side by a reef, and reefs tend to grow
in shallow water where they can get sunlight to keep the reef forming
organisms alive, and forming new reef. Reefs grow when water levels
are rising because they grow upward and forward to stay in the sunlight.
Reefs die when water levels drop.
Any way, it makes a lot of sense that what happens locally in our
part of the galaxy can have profound influences on what happens to
the Earth, and its surface features, and it surface life forms.
It also makes sense that what ever happens might be cyclical,
and not very beneficial to the species on the surface, and in the water
at the time.
Going out with a bang might be more literal than we want to
recognize and accept.
To John Houghton
The wall chart ( A CORRELATED HISTORY OF THE EARTH )
is available from PAN TERRA, INC. Hill city, South Dakota.
Just type the chart name directly into a GOOGLE search, and it will
pop up. They also have one that folds up like a state map. Both are laminated.
The reason I did not respond is that Colorado got flooded, and all of my
people went to the Northern end of the state to rebuild roads and bridges
before December 1. That leaves me finishing a bridge ( administration ),
with one consultant inspector, so we are both working long hours.
Anyway, back to the Earth, The " Correlated History " Author uses a
186 MY cycle, I used the concept to refine the cycle, first to 186.6, and
recently to 186.62 MY ( to a ridiculous number of digits ).
Side Bar: The age of the Earth and the Moon can be determined from
rate of recession of the moon away from the Earth, which in turn
is based on the differential rate of mass gain of the two planets.
The Earth, being far larger than the Moon gains mass at a far greater rate
( 1.3 x 10^15 kg per year ), and is current mass is roughly
5.97352 E 24 KG. The elapsed time is thus about
( 5.97352 / 1.3 ) E 9 years = 4595 MY, but you have to multiply this number
by a mass ratio ( Moon = 1, Earth = 81.30059122 )
So 81.30059122 / 82.30059122 = 0.987849419 X 4595 = 4539.168.
The 1.3 is not exact, it is less, so I will use my prior calculated number
of 4544.40 +/- 25.98 MY for the Earth Age. So now that we have the age of the
Earth, and if we assume from Earth's History that Extinctions are
cyclical ( Nodal ), then there are " N " nodes and a fraction of the next cycle.
That fraction based on the Iridium Spike at 65.50 MYA, provides a node.
So by process of back calculation:
4544.40 - 65.50 = 4478.9 / N is about equal to 186 more or less.
4478.9 / 24 = 186.6208333 ( Round to 186.62 MY per cycle ).
So we calculate the last 4 or 5 primary extinctions:
65.50 + 0 x 186.62 = 65.50 MYA
65.50 + 1 x 186.62 = 252.12 MYA
65.50 + 2 x 186.62 = 438.74 MYA
65.50 + 3 x 186.62 = 625.36 MYA
65.50 + 4 x 186.62 = 811.98 MYA
Then we go look in the Wall Chart, and compare it to
all of the " A " extinction events :
A , crater diameter, crater location, Date MYA
A, 180 km, Chicxulub, Yucatan Peninsula, 66 MYA
A, 250 km, Wilkes Land, ( 3 to 4 large Impacts ) , 252 MYA
A, ( Possible Major Impacts), Balhash Lake, Tengiz, Kazakhstan, 438 MYA
A, ( 624 MYA ) ( 620- Impact on Venus, Venus resurfaced )
A, ( 812 MYA) ( 800 - Copernicus - Moon )
That is the A cycle, I have not yet worked on the B, C, D, E, F, G
cycles which should also be on the 186.62 MY cycle,
but There will be variations and differences.
If you go to the Geologic Ages:
65.50 = K-T Boundary
251 = Permian Triassic Boundary
444 = Ordovician - Silurian Boundary It might be 439 ????
630 = World Wide Unconformity ( Global Glaciers melt, and
larger life forms appear in the oceans )
Back tracking: 24 x 186.62 + 65.50 = 4544.38 MY.
This is one of those things where feeding information into a
computer program, and letting it find the nodes of
the 7 cycles to find the time lapse between nodes,
and then averaging the seven would be far more productive.
Normally I would agree that up lift of continents ( specifically differential
rate of up lift of continents ) would be a practical assumption, but
the Salt beds of the Salar de Uyuni ( one salt, or unified salt , I suppose )
are incredibly flat. It is the largest and flattest salt flat on earth, and it
is roughly at a 10,000 foot elevation. Being flat NASA and the US Military
use it to calibrate the elevation of the Global Positioning System Satellites .
Any way, I got to thinking that maybe is can be classified as a residual
remaining High elevation Plateau similar to the Himalayan Plateau.
In short it is too high to have a thinning continent under it.
The concept is that roughly 250 million years ago the Earth began changing the
rate that it grows larger from about 3 mm per year back then to about
23 mm per year now, with a corresponding 18 mm per year continental settlement
as materials are removed from under the continent to feed the newer, and still forming
ocean floors. The current net change is thus 23 up minus 18 down = 4 up net.
The thinning of the continents from underneath to supply materials flowing toward
the ocean ridges creates differential vertical motions at the margins because
continents are settling, while ocean floors are rising . This creates a bending moment in the rock at the edges of the continents which creates the illusion
of Subduction.
In other words this is active ongoing isostacy where the global vertical forces
of gravity redistribute materials both horizontally and vertically to minimize the
differences in over-burden pressures, and move less dense materials upward.
Simplified: Materials flow to minimize the force differences,
the pressure differences, and to maximize the density differences.
At the Mid Oceanic Spreading Ridges where magma is released, the
upward curvature of the ridges is a sequential record of the depth
of the water at the instant the magma was released and cooled.
If the oceans get deeper, the magma cools at a lower elevation.
if the oceans get thinner, the magma cools at a higher elevation.
Since the general overall trend has been for the magma ridges to curve
upward, the oceans have been getting thinner. This implies that the
surface area of the planet is now increasing faster than the new
Juvenile water can form from hydrogen and oxygen inside the earth,
so the oceans are thinning, and the sea floor is curving upward
as a result of that thinning.
This also implies that the continents could have averages up to
103 km thickness 252 million years ago, but have thinned to
an average of 38.8 km thick currently.
This thinning process would not be uniform. it wold leave
larger continents higher in the center, ( Eurasia ), and submerged at the
perimeters, and the very smallest continental fragments
almost entirely submerged ( New Zealand ) .
It would simply involve the total elapsed time, and the average
lateral distance the material must flow as to whether it
remains above the ocean waves, or becomes completely submerged.
Since the Continental land mass under new Zealand is only about 1/3
that of Australia, is now only has the Mountain tops showing.
An increase in the planets radius and surface area also explains
why the oceans poured off the continents, leaving behind reefs,
and marine fossils.
The question here, despite the considerable discussion above, is very simple. Are there any extrasolar meteorites? Answer: None are known at present. There is, however, considerable evidence of the presence of discrete extrasolar system materials within many known meteorites. Discrete mineral grains that are unequivocal samples of non-solar system minerals have been analyzed and discussed at considerable length over the last twenty years. Probably since Roy Lewis' separation of interstellar diamonds from several carbonaceous chondrites. Thus well characterized interstellar objects are present in many modern laboratories, but there ar NO meteorites that are COMPLETELY from outside the Solar System/nebula.
Pre solar material can be found but would anybody explain if it is possible for any extrasolar material that can survive if ever it can enter the solar system!!!
Couple of brief points
1. Remember the solar system violently ejected much interplanetary debris after the planets Uranus and Neptune formed (20 earth masses each) into what would become the Oort Clouds (google on Savronov theory - still controversial). So we are impacted by debris that was part of the solar nebula at one point so some meteorites could come form those regions (but almost all come from the asteroid belt region). Nothing ever has been discovered on the Earth that has a chemical composition suggesting it was not part of the original solar nebula.
2. Mass extinctions can occur for a variety or reasons:
a) impact triggered (KT Event)
b) large changes in atmospheric and ocean chemistry - Siberian basalt flows in the Permian
c) high supernova background because we are in a spiral arm - this happens roughly every 120 million years with a duration period of 10 million years - some evidence that at least one of the 5 major extinction events over the last 500 million years is due to this.
d) Snowball Earth
e) Hot house earth
It also useful to define mass extinctions as events that extinct > 80 % of the
specials
There are several dozen events over the last 500 million years at the < 30% level -
some of those are related to Ice Age events.
The answer may seem possible to the original question....if somebody can throw light on the criteria that can distinguish outside-solar material from the solar material!!!!
Although it is highly unlikely that we will ever find extra-Solar meteorites on Earth it is not impossible. So how could we recognize them?
Most meteorites found on the Earth date back to the birth of the Solar system. Most of these meteorites include examples of the oldest dateable objects that we know of - the so-called CAIs. With an age of 4567.3 million years CAIs define the age of our Solar System. Finding meteorites carrying particles that formed before our Solar System would certainly be evidence that they formed outside the solar system.
The stable isotope ratios of such meteorites would almost certainly also be rather different from that of our solar system. Stable isotopes reflect the particular set of stars that delivered matter to our Solar System - and it would be highly unlikely to find a different solar system with exactly the same ratios.
Finally, having only seen primitive material from our own solar system, all experience tells us that similar meteorites from a different system would likely be quite different from those of our own system - in ways we can only speculate about.
Thanks Hanning...Yes I have a feeling that may be some scientist could have come across a material (meteorite) that gave him age more than 4.6 Ga but he must have doubted his results or instrument or whatever....though there can be such probability because planets of other stars might be behaving same way as our Solar System hence the material from that star system (of'course if it formed earlier than our Solar System...which is quite likely) can give an older age......But with the present knowledge I am not sure whether it is possible for the material to be thrown off its star-system-limit and secondly, if ever it gets thrown and enters another star-system then are there any chances for that material to remain unaffected!!
1. no one has ever measured a date on earth older than 4.6
2. the only way your second hypothesis could old is if the solar system formed
at a time when the sun was in a spiral arm and the local stellar density was
at least an order of magnitude higher than currently. This seems unlikely
Amir Siraj & Abraham Loeb (2019) Discovery of a Meteor of Interstellar Origin. Preprint Discovery of a Meteor of Interstellar Origin
"Based on the CNEOS catalog of bolide events, we identify the ∼0.45m meteor detected at 2014-01-08 17:05:34 UTC as originating from an unbound hyperbolic orbit with an asymptotic speed of v∞∼43.8kms−1 outside of the solar system. Its origin is approximately towards R.A. 3h24m and declination +10.4∘, implying that its initial velocity vector was ∼60kms−1away from the velocity of the Local Standard of Rest (LSR). Its high LSR speed implies a possible origin from the deep interior of a planetary system or a star in the thick disk of the Milky Way galaxy."
Not one meteorite has been shown to be extrasolar (easily determined through isotope analysis), and rocks or irons would not likely survive the high entry velocities expected of galactic material.
The Earth is orbiting the Sun at 30 km/sec, which happens to also be a typical random (or peculiar) velocity of stars (and this presumably meteors) in interstellar space, while anything that fell into the solar gravity well with zero initial velocity will be moving at 45 km / sec by the time it goes by the Earth. The _minimum_ relative velocity of an interstellar meteorites will thus be (45 - 30) ~ 15 km/sec, which will be rare; most will enter the atmosphere at order 60 km /sec or more. Anything entering at that high velocity will not survive, but there might be a very small number of doubly lucky interstellar meteors (their galactic velocities matching the Sun's, and their hyperbolic velocities aligned with the Earth's) that survive and make it to the Earth's surface. As several respondents have stated, small extrasolar (or presolar) _grains_ are common in meteorites, from material present at the formation of the solar system, and easily found from isiotope analysis, but this is different from an entire and complete interstellar meteorite. https://www.sciencedirect.com/science/article/pii/S0032063301000253
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