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  • G David Bock
    replied
    Presented more for the images it has than than the title, FYI~FWIW;
    Has an alien probe entered our solar system? Cigar-shaped interstellar 'comet' Oumuamua is being investigated for signs of extraterrestrial technology

    • Astronomers are set to scan an 'alien' comet for signs of extraterrestrial signals
    • The cigar-shaped object, named 'Oumuamua, sailed past Earth last month
    • The mysterious comet is the first interstellar object seen in the solar system
    • Now a team of alien-hunting scientists led by Russian billionaire Yuri Milner is scanning the object for radio signals

    By Harry Pettit For Mailonline
    Published: 12:20 EST, 11 December 2017 | Updated: 06:33 EST, 12 December 2017
    Last edited by G David Bock; 12 Dec 17, 18:06.

    Leave a comment:


  • G David Bock
    replied
    Ooohps

    Asteroid that could’ve obliterated NYC skimmed past Earth – and NASA didn’t notice

    A MASSIVE asteroid that could have destroyed New York City skimmed past Earth – and NASA had no clue.
    ...
    The large space rock – dubbed 2017 VL2 – passed the planet on November 9 at an astonishing distance of just 73,000 miles, which is considered tiny in space terms.
    Space boffins think that if the rock measuring between 16 and 32 metres had hit, it could’ve wiped a major city such as New York off the map.
    The rock belongs to the Apollo group of asteroids and was first seen at ATLAS-MLO observatory in Hawaii a day later.
    It was travelling at a speed of 8.73km/s and would have caused catastrophic damage if it had made impact.
    ...
    https://www.dailystar.co.uk/news/lat...-new-york-city

    Leave a comment:


  • G David Bock
    replied
    Originally posted by Pirate-Drakk View Post
    Think MIRV (multiple independent reentry vehicles) used for nukes...
    The thing about MIRVs is that the concept was that say six smaller devices each targeted to a specific ICBM silo were more likely to take out all to most whereas a single BIG one would have a smaller area of blast effect and only take out a few at best. Also, in large, sprawled "urban" areas you could damage the human structures over a larger square mile surface than with a single big one. The concept was also a way to get more "BANG" with fewer launch vehicles used.

    In the case of asteroid impact, I'm reminded of an "experiment" I did several years ago using one of my 12 guage shotguns. We were out in the "boonies" at a place were many people in the county would go to shoot and someone prior had left one of those old tub style washing machines out there. I found an aera where the surface had been shot at and then conducted my test;

    First I fired a round of birdshot, #7 or 8 IIRC, about three dozen pellets the size of a BB, and noticed a lot of dippled impressions in an area of about 3-4 inches diameter, but no penetrations.

    Next I fired a round of buckshot (00), about nine pellets the size of a 9mm pistol round. They had a smaller area of impact, but did penetrate through the first wall, but not the second.

    Next I fired a slug(solid) round. It made a 1-2 inch entry hole and slightly smaller exit hole on the other side wall.

    In asteriod impact terms;

    A 2-3 mile rock will create a smaller sized area of impact, but the deeper penetration and concentration of energy is such that the secondary effects, seismic disruptions and/or tsunamies could have near global reach and effect.(slug shot)

    A 2-3 mile sized rock, broken into several or more pieces will produce a larger sized area of multiple impacts, but the total scope of energy and damged will be lessor than of the original solid object. (buckshot)

    A 2-3 mile sized rock broken into dozens of smaller rocks will have an even larger area of surface impact, but the reduced penetration and energy will yield the lowest net damage effect, especially on a planet wide scale. (birdshot)

    I probably should do a youtube of this.

    Leave a comment:


  • Pirate-Drakk
    replied
    Originally posted by G David Bock View Post
    However, spreading one LARGE impact into say a Dozen smaller impacts could result in a larger scale of destruction, especially from a human perspective/effects, but here the veriable is in the where and when.
    Think MIRV (multiple independent reentry vehicles) used for nukes...

    Leave a comment:


  • G David Bock
    replied
    At about three mile size, this could be a killer, but at about two million mile distance, hardly "grazing" i'd say;
    https://www.dailystar.co.uk/news/lat...as-december-17

    Leave a comment:


  • G David Bock
    replied
    Originally posted by Moulin View Post
    I would think breaking up would be more devastating regarding extinctions world wide
    Actually, likely to be less, but there are those variables.

    A single mass broken into several smaller will usually offer mopre surface area upon atmospheric entry to result in a greater mass reduction.

    Destruction in general is a basic equation of mass times velocity(near constant for any sized object due to Earth's gravity well) equals impact results. Reducing a large single mass into many smaller ones will usually increase the total surface area subject to abolation~atmospheric resistence=heat burn off and in essense usually mean a smaller mass impacting.

    However, spreading one LARGE impact into say a Dozen smaller impacts could result in a larger scale of destruction, especially from a human perspective/effects, but here the veriable is in the where and when. If mostly upon ocean could likely be "small scale", but if upon the right locations of hard land, say cities/urban areas could be very devestating.

    Net "bottom-line", not something to roll dice on if avoidable.

    Leave a comment:


  • Moulin
    replied
    I would think breaking up would be more devastating regarding extinctions world wide

    Leave a comment:


  • G David Bock
    replied
    Originally posted by G David Bock View Post
    Amoung the timing and placement variables, consider the Tunguska Event of just over a century ago. Had this happened a few hours later (and maybe a few degrees lower in latitude) and had the object been "busted up" into several impactors, the results may have had a major set-back to global history in the destruction that might have occurred to Europe.

    https://en.wikipedia.org/wiki/Tunguska_event
    ...
    The Tunguska event was a large explosion that occurred near the Stony Tunguska River in Yeniseysk Governorate (now Krasnoyarsk Krai), Russia, on the morning of 30 June 1908 (N.S.).[1][2] The explosion over the sparsely populated Eastern Siberian Taiga flattened 2,000 km2 (770 sq mi) of forest yet caused no known human casualties. The explosion is generally attributed to the air burst of a meteoroid. It is classified as an impact event, even though no impact crater has been found; the object is thought to have disintegrated at an altitude of 5 to 10 kilometres (3 to 6 miles) rather than hit the surface of the Earth.[3]

    The Tunguska event is the largest impact event on Earth in recorded history. Studies have yielded different estimates of the meteoroid's size, on the order of 60 to 190 metres (200 to 620 feet), depending on whether the body was a comet or a denser asteroid.[4]

    Since the 1908 event, there have been an estimated 1,000 scholarly papers (most in Russian) published on the Tunguska explosion. In 2013, a team of researchers published analysis results of micro-samples from a peat bog near the center of the affected area showing fragments that may be of meteoritic origin.[5][6]

    Early estimates of the energy of the air burst range from 10–15 megatons of TNT (42–63 PJ) to 30 megatons of TNT (130 PJ),[7] depending on the exact height of burst estimated when the scaling-laws from the effects of nuclear weapons are employed.[7][8] However, modern supercomputer calculations that include the effect of the object's momentum find that more of the energy was focused downward than would be the case from a nuclear explosion and estimate that the airburst had an energy range from 3 to 5 megatons of TNT (13 to 21 PJ).[8]

    The 15 megaton (Mt) estimate represents an energy about 1,000 times greater than that of the atomic bomb dropped on Hiroshima, Japan — roughly equal to that of the United States' Castle Bravo (15.2 Mt) ground-based thermonuclear detonation on 1 March 1954, and about one-third that of the Soviet Union's Tsar Bomba explosion on October 30, 1961 (which, at 50 Mt, was the largest nuclear weapon ever detonated).[9]
    It is estimated that the Tunguska explosion knocked down some 80 million trees over an area of 2,150 square kilometres (830 sq mi), and that the shock wave from the blast would have measured 5.0 on the Richter magnitude scale. An explosion of this magnitude would be capable of destroying a large metropolitan area,[10] but, due to the remoteness of the location, no human fatalities were officially documented. Several reports have indicated that two people may have died in the event, however these deaths remain unofficial.[11][12][13][14] This event has helped to spark discussion of asteroid impact avoidance.
    ...
    https://en.wikipedia.org/wiki/Tunguska_event
    Point being that efforts to deflect and/or reduce composition of a potential impactor could result in even worse Impact Event than originally in line for.

    Leave a comment:


  • G David Bock
    replied
    Originally posted by G David Bock View Post
    Maybe, but net effect could have been the same to slightly less. There are many variables to consider.

    Generally speaking, anything over about 2-3 miles size can and could cause significant biosphere damage that could take centuries to millenia for Nature to recover from.

    "broken up slightly" depends upon the mechanics/math of such. ...

    ... If broken into smaller pieces and on a horizontal axis, roughly same impact time range, one might defuse overall destructive level while spreading such over a larger area, circle of impact.

    Alternatively one might get a staggered imapct area~time range like in case of Shoemaker-Levy9 https://en.wikipedia.org/wiki/Comet_...E2%80%93Levy_9 which could result in larger and greater destruction zones.

    Lots of variables involved but my studies to date suggest a single impact event is usually better over a larger impact event and deflection away from Earth is Best yet.
    Amoung the timing and placement variables, consider the Tunguska Event of just over a century ago. Had this happened a few hours later (and maybe a few degrees lower in latitude) and had the object been "busted up" into several impactors, the results may have had a major set-back to global history in the destruction that might have occurred to Europe.

    https://en.wikipedia.org/wiki/Tunguska_event
    ...
    The Tunguska event was a large explosion that occurred near the Stony Tunguska River in Yeniseysk Governorate (now Krasnoyarsk Krai), Russia, on the morning of 30 June 1908 (N.S.).[1][2] The explosion over the sparsely populated Eastern Siberian Taiga flattened 2,000 km2 (770 sq mi) of forest yet caused no known human casualties. The explosion is generally attributed to the air burst of a meteoroid. It is classified as an impact event, even though no impact crater has been found; the object is thought to have disintegrated at an altitude of 5 to 10 kilometres (3 to 6 miles) rather than hit the surface of the Earth.[3]

    The Tunguska event is the largest impact event on Earth in recorded history. Studies have yielded different estimates of the meteoroid's size, on the order of 60 to 190 metres (200 to 620 feet), depending on whether the body was a comet or a denser asteroid.[4]

    Since the 1908 event, there have been an estimated 1,000 scholarly papers (most in Russian) published on the Tunguska explosion. In 2013, a team of researchers published analysis results of micro-samples from a peat bog near the center of the affected area showing fragments that may be of meteoritic origin.[5][6]

    Early estimates of the energy of the air burst range from 10–15 megatons of TNT (42–63 PJ) to 30 megatons of TNT (130 PJ),[7] depending on the exact height of burst estimated when the scaling-laws from the effects of nuclear weapons are employed.[7][8] However, modern supercomputer calculations that include the effect of the object's momentum find that more of the energy was focused downward than would be the case from a nuclear explosion and estimate that the airburst had an energy range from 3 to 5 megatons of TNT (13 to 21 PJ).[8]

    The 15 megaton (Mt) estimate represents an energy about 1,000 times greater than that of the atomic bomb dropped on Hiroshima, Japan — roughly equal to that of the United States' Castle Bravo (15.2 Mt) ground-based thermonuclear detonation on 1 March 1954, and about one-third that of the Soviet Union's Tsar Bomba explosion on October 30, 1961 (which, at 50 Mt, was the largest nuclear weapon ever detonated).[9]
    It is estimated that the Tunguska explosion knocked down some 80 million trees over an area of 2,150 square kilometres (830 sq mi), and that the shock wave from the blast would have measured 5.0 on the Richter magnitude scale. An explosion of this magnitude would be capable of destroying a large metropolitan area,[10] but, due to the remoteness of the location, no human fatalities were officially documented. Several reports have indicated that two people may have died in the event, however these deaths remain unofficial.[11][12][13][14] This event has helped to spark discussion of asteroid impact avoidance.
    ...
    https://en.wikipedia.org/wiki/Tunguska_event

    Leave a comment:


  • G David Bock
    replied
    Originally posted by Moulin View Post
    would it have broken up slightly into many pieces?
    Maybe, but net effect could have been the same to slightly less. There are many variables to consider.

    Generally speaking, anything over about 2-3 miles size can and could cause significant biosphere damage that could take centuries to millenia for Nature to recover from.

    "broken up slightly" depends upon the mechanics/math of such. ...

    ... If broken into smaller pieces and on a horizontal axis, roughly same impact time range, one might defuse overall destructive level while spreading such over a larger area, circle of impact.

    Alternatively one might get a staggered imapct area~time range like in case of Shoemaker-Levy9 https://en.wikipedia.org/wiki/Comet_...E2%80%93Levy_9 which could result in larger and greater destruction zones.

    Lots of variables involved but my studies to date suggest a single impact event is usually better over a larger impact event and deflection away from Earth is Best yet.

    Leave a comment:


  • Moulin
    replied
    Originally posted by G David Bock View Post
    The Asteroid That Killed the Dinosaurs Caused Catastrophic Climate Change

    https://www.seeker.com/earth/climate...climate-change
    would it have broken up slightly into many pieces?

    Leave a comment:


  • G David Bock
    replied
    The Asteroid That Killed the Dinosaurs Caused Catastrophic Climate Change

    https://www.seeker.com/earth/climate...climate-change

    Leave a comment:


  • Widow Maker
    replied
    Originally posted by G David Bock View Post
    OK guys, long day and late night so I'm trying this visualization ...

    Lets take a sheet of paper and make the X and Y axis cross on such.
    Place the incoming rock/NEO at the center where the lines cross.
    Using one inch equals 4,000 miles (we're rounding here), make a mark one inch to the left on the X (horizontal) line; this locates the Earth's surface closest to the NEO.

    Now go another inch to the left on X and mark this point. With a drawing compass set for one inch radius and on this "two inch" point, draw a one inch radius/two inch diameter circle to represent Earth.

    Now from the X=0/Y=0 location of the NEO, set the compass for 4 inch radius circle and draw it. Four inches equals two Earth diameters (2 x 8,000 miles). Looks to me like Earth is within that circle, which is what Pirate-Drakk gave us.

    If we draw an eight inch radius circle from 0/0 we have a much large circle but one that still has Earth within it, this one from Widow-Maker.

    Looks to me like anything over a one Earth radius margin of error could place Earth in an impact zone.

    Of course the larger error factors could suggest it might pass by on the far side of Earth from where it is expected, missing by a long mile(s).

    BTW, at this scale the Moon is about 5 feet (59.5") further out on the X Axis from Earth.
    Like you pointed out in your post 262 NASA and the major observatories are calling for it to miss earth by more than 27,000 miles. Well outside their (now more refined) margin of error.

    Leave a comment:


  • Pirate-Drakk
    replied
    Originally posted by G David Bock View Post
    Hopefully that is so.
    In the case of this one; 2012 TC4, seems we don't have enough data and numbers to be certain. It's already shifted from 4,200 miles to about 27,300 miles away (from Earth's surface, not center ~ which would add another @4,000 miles).
    27,300 - 4,200 = 19,100 miles error from their first guess

    Twice the Earth's diameter is 15,834 miles, so they were slightly worse than my speculation.

    Good thing the latest number is the more accurate one...

    Leave a comment:


  • G David Bock
    replied
    A THREE MILE wide asteroid is set to graze past Earth on Sept. 1 - and NASA says it's the largest to come this close since they began keeping track

    • NASA says asteroid that's 2.7 miles wide will make 'relatively close encounter'
    • Dubbed ‘Florence,’ the space rock will pass 4.4 million miles from our planet
    • This is the closest an object this large has come since NASA began NEO program
    • It hasn't come this close since 1890, and won't be this close again until 2,500

    Leave a comment:

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