Joselela
JF-Expert Member
- Jan 24, 2017
- 5,676
- 6,961
Chance of Impact in 2027 is Now 96%
Based on new tracking observations taken this week, IAWN has
confirmed that asteroid 2017 PDC is on a course that almost certainly
will impact the Earth on July 21, 2027, less than 9 years from now
• The asteroid brightened just enough to be detected by the NASA’s
Hubble Space Telescope (HST) and the National Astronomical
Observatory of Japan’s large 8-meter Subaru Telescope
• The new measurements did not eliminate the possibility of impact, as
had been hoped; IAWN now estimates the impact probability at 96%
• Prior to this week the asteroid was unobservable for 11 months, during
which time the impact probability was 26%; after this week the asteroid
is again too faint to be observed for another 11 months
• The possible impact locations are confined to a region stretching from
China, across North and South Korea, Japan, and into the Pacific
___________________________________________________
In 2027 the earth will end, there's nothing we can do about it, so why panic? Just accept it. And there's of course a 4% chance that nothing will happen. No need to be alarmed.
Ok, sarcasm aside, we all know now that the link is about an exercise. But what could happen?
Well, turns out it happened before, fairly recently even, in 1908. A 190m (close enough) meteor exploded some 5 miles or so above the Russian wilderness. No one died. It cause 2000 square km of forest to be knocked over.
So it really depends on where it would hit. Middle of the ocean? Big tsunami I guess. Middle of New York? Everyone there dies probably. Middle of the desert? Huge dust clouds cover the planet for a while. But earth will definitely not end. 200m is way too small.
Besides, if we already knew which one it is, and when it hit, we could calculate pretty closely where it hit, and take precautions. We have 8 years time. And I would get the militaries of the world would try to shoot it down or knock it off course. It's small enough for that, and maybe possible if its long and flat or so. And the impact speed would be 20km/sec, like the one in Russia a few years back. If we shoot at it from say 5000km we'd have a few minutes at least to try. Like I said it would be small enough.
___________________________________________________
Update on Physical Properties of 2017 PDC
• IAWN updated its size estimate for 2017 PDC based on NEOWISE
observations; the new size estimate is 200 to 280 meters
– Indicates a relatively low albedo of roughly 4% to 8%
• Spectral measurements made in May and June 2017 indicate that
2017 PDC is a C-type asteroid
• Further refinements to the taxonomy will be available soon from the
recently launched James Webb Space Telescope (JWST)
• Back in April 2017, radar astronomers had already put an upper bound
of 300 meters on the size estimate based on non-detection at 0.13 au
• Photometry and light-curve measurements were also made in April
through June 2017, but they were ambiguous and a definitive rotation
period was not established; non-priniciple-axis (NPA) rotation is
indicated
Impact Risk Assessment Summary
• Simulated 1000 impact cases for each swath point, sampling from
uncertainty distributions of size (diameter or H-mag/albedo), density,
and strength according to the given knowledge about the asteroid for
each inject option.
• Local population affected by blast overpressure and/or tsunami is
computed for each sampled impact case.
•For blast overpressure, different fractions of the population are counted as
affected depending on the blast overpressure level: 10% of people within the
1-2 psi zone, 30% within the 2-4 psi zone, 60% within the 4-10 psi zone, and
100% within the 10+ psi zone.
•For tsunami, fractions of the inundated population are counted as casualties
depending on flood depth (averaging to about 10% of the inundated
population).
•The maximum affected population from blast or tsunami is taken as the
affected population for each sampled impact case.
SOURCE: https://cneos.jpl.nasa.gov/pd/cs/pdc17/day2.html
Based on new tracking observations taken this week, IAWN has
confirmed that asteroid 2017 PDC is on a course that almost certainly
will impact the Earth on July 21, 2027, less than 9 years from now
• The asteroid brightened just enough to be detected by the NASA’s
Hubble Space Telescope (HST) and the National Astronomical
Observatory of Japan’s large 8-meter Subaru Telescope
• The new measurements did not eliminate the possibility of impact, as
had been hoped; IAWN now estimates the impact probability at 96%
• Prior to this week the asteroid was unobservable for 11 months, during
which time the impact probability was 26%; after this week the asteroid
is again too faint to be observed for another 11 months
• The possible impact locations are confined to a region stretching from
China, across North and South Korea, Japan, and into the Pacific
___________________________________________________
In 2027 the earth will end, there's nothing we can do about it, so why panic? Just accept it. And there's of course a 4% chance that nothing will happen. No need to be alarmed.
Ok, sarcasm aside, we all know now that the link is about an exercise. But what could happen?
Well, turns out it happened before, fairly recently even, in 1908. A 190m (close enough) meteor exploded some 5 miles or so above the Russian wilderness. No one died. It cause 2000 square km of forest to be knocked over.
So it really depends on where it would hit. Middle of the ocean? Big tsunami I guess. Middle of New York? Everyone there dies probably. Middle of the desert? Huge dust clouds cover the planet for a while. But earth will definitely not end. 200m is way too small.
Besides, if we already knew which one it is, and when it hit, we could calculate pretty closely where it hit, and take precautions. We have 8 years time. And I would get the militaries of the world would try to shoot it down or knock it off course. It's small enough for that, and maybe possible if its long and flat or so. And the impact speed would be 20km/sec, like the one in Russia a few years back. If we shoot at it from say 5000km we'd have a few minutes at least to try. Like I said it would be small enough.
___________________________________________________
Update on Physical Properties of 2017 PDC
• IAWN updated its size estimate for 2017 PDC based on NEOWISE
observations; the new size estimate is 200 to 280 meters
– Indicates a relatively low albedo of roughly 4% to 8%
• Spectral measurements made in May and June 2017 indicate that
2017 PDC is a C-type asteroid
• Further refinements to the taxonomy will be available soon from the
recently launched James Webb Space Telescope (JWST)
• Back in April 2017, radar astronomers had already put an upper bound
of 300 meters on the size estimate based on non-detection at 0.13 au
• Photometry and light-curve measurements were also made in April
through June 2017, but they were ambiguous and a definitive rotation
period was not established; non-priniciple-axis (NPA) rotation is
indicated
Impact Risk Assessment Summary
• Simulated 1000 impact cases for each swath point, sampling from
uncertainty distributions of size (diameter or H-mag/albedo), density,
and strength according to the given knowledge about the asteroid for
each inject option.
• Local population affected by blast overpressure and/or tsunami is
computed for each sampled impact case.
•For blast overpressure, different fractions of the population are counted as
affected depending on the blast overpressure level: 10% of people within the
1-2 psi zone, 30% within the 2-4 psi zone, 60% within the 4-10 psi zone, and
100% within the 10+ psi zone.
•For tsunami, fractions of the inundated population are counted as casualties
depending on flood depth (averaging to about 10% of the inundated
population).
•The maximum affected population from blast or tsunami is taken as the
affected population for each sampled impact case.
SOURCE: https://cneos.jpl.nasa.gov/pd/cs/pdc17/day2.html
