Re: "NASA to study "city-killer" asteroid as odds of hitting Earth go up"

In article <7tkpqj96to3o6e4u9pvl2qdff07s5uoqqk@4ax.com>,
Paul S Person  <psperson@old.netcom.invalid> wrote:

On Wed, 12 Feb 2025 11:28:09 +0100, D <nospam@example.net> wrote:
>

>
>
On Tue, 11 Feb 2025, Dimensional Traveler wrote:
>

On 2/11/2025 5:12 PM, Lynn McGuire wrote:

"NASA to study "city-killer" asteroid as odds of hitting Earth go up"
 
https://www.msn.com/en-us/news/technology/nasa-to-study-city-killer-
asteroid-as-odds-of-hitting-earth-go-up/ar-AA1yLdde
 
"Astronomers are enlisting the help of NASA's James Webb Space

Telescope to

study an asteroid that has a small chance of striking Earth less

than eight

years from now. Characterized as a potential "city-killer," the asteroid
was first detected in December and its odds of impacting our planet have
increased slightly since then, according to the European Space Agency."
 
�The space rock is formally named 2024 YR4. Scientists say it currently
carries a 2% risk of making contact with Earth when it eventually reaches
this part of the solar system on Dec. 22, 2032. Although the asteroid will
most likely pass by without issue, those tasked with monitoring its
physical attributes and potential have shifted upward the probability of a
crash since 2024 YR4 was initially discovered.�
 
Am I the only person who is suspicious of NASA crying wolf ?
 

I don't see any wolf crying.  They are refining their data to improve their
accuracy.

>
This would be my interpretation. Plenty of time left, they are keeping an
eye on it. Will it hit? If not, no problem. If yes, where will it hit? If
random ocean, no problem. If not random ocean, maybe little bit problem.

>
I suggest watching /Sudden Impact/ to get an idea of what a chunk of
space rock hitting an ocean can do.

Alas, I just came across the relevant equations.

wave height for an impact in deep water is roughly

h = 6.5m [y/gigaton] 0.54 [1000km/r]

h = wave height
r = range to impact
y = yield

Idealised wave run in (which is to say, not applicable to any real region):

Xmax ~ 1.0km [h/10 meters]^[4/3]

Plug in 8 MT and that's 0.02 meters at 1000 km, with a run in of 0.005 m.
I think.

As wave height is linear wrt r but run in has that power of 1.3,
reducing r should have interesting effects on run in. However,
running the numbers suggests that by the time you're close enough
to worry about the wave, you're also close enough to be crushed
and set on fire by the impact. 

--
My reviews can be found at http://jamesdavisnicoll.com/
My tor pieces at https://www.tor.com/author/james-davis-nicoll/
My Dreamwidth at https://james-davis-nicoll.dreamwidth.org/
My patreon is at https://www.patreon.com/jamesdnicoll