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

On Sun, 16 Feb 2025 16:40:22 -0000 (UTC), jdnicoll@panix.com (James
Nicoll) wrote:

In article <struqjd0up33dp7peo9h8bavv380j43efc@4ax.com>,
Paul S Person  <psperson@old.netcom.invalid> wrote:

On Thu, 13 Feb 2025 17:19:14 -0000 (UTC), jdnicoll@panix.com (James
Nicoll) wrote:
>

In article <608sqjle4440ka7d2tnb3b8n1hjam30skt@4ax.com>,
Paul S Person  <psperson@old.netcom.invalid> wrote:

On Wed, 12 Feb 2025 22:31:04 +0100, D <nospam@example.net> wrote:
>

>
>
On Wed, 12 Feb 2025, Paul S Person 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.
>

>
I thought you smart enough not to assume random ocean meant 10 meters
outside new york.
>
Tsunami schnunami, we've dealth with that and survived. If we have a
couple of years advance warning we're good to go.

>
First, as has been pointed out to me, the film I meant to cite was
/Deep Impact/.
>
Second, it is not "10 meters off New York".
>
Third, we had a year. We were /not/ good to go.
>
But I have also read a post with actual figures in it, so apparently
the film exaggerated things a bit.

>
My numbers were for a dinky 8 MT impact, whereas Deep Impact involved
a rock the size of Everest. Whole different game.

>
That's the one that hit the ocean, not the much larger planet-killer
to come, right?
>
So, what do the formulae show for the /Deep Impact/ ocean strike?
>

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]
>
Impact energy in Deep Impact seems to be 500,000 MT.
>
At 1000 km, the wave would be 6.5x500x.54 or about 1800 m, which seems
kind of bad.

It looks /very/ impressive in the movie!

h/10 is 180, so Xmax is almost exactly 1000 km, which also seems bad.
Mind you, that wave is going to have a heck of a time getting past
the Appalachians so Ontario should be fine.

The second one, had it hit, would have hit on the Canadian Shield
(IIRC). Bing suggests that this is not Ontario, but, since this is
"the planet-killer", not actually being hit wouldn't matter much.

In the film, we see it go up a valley while the survivors climb the
surrounding hills. This is the bit I am using as a counter-example to
the "water lapping gently at the seashore" nonsense promoted by some.
The coastal cities, of course, are gone. I would think Labrador would
be impacted as well, but I'm sure how far north of the impact they
are.

I seem to recall from the bit at the end indicating that the water
reached over the Appalachians into the Ohio valley (and related areas)
before receding. The amount of water and the force with which it moved
would, of course, be constantly reducing once it hit land.

So, yes, Ontario (and everything West of the Mississippi for that
matter) would have escaped.
--
"Here lies the Tuscan poet Aretino,
Who evil spoke of everyone but God,
Giving as his excuse, 'I never knew him.'"