Asteroid 2024 RW1 - entered Earth's atmosphere over Luzon, Philippines

[Astronuc]

On 4 September at 16:39 UTC (18:39 CEST), a small asteroid entered Earth's atmosphere near the Philippines, exploding in a fireball witnessed by people in the region.

The object was discovered by the Catalina Sky Survey exactly 10 hours before impact, at 06:39 UTC (08:39 CEST). Within minutes of discovery, automatic asteroid warning systems such as ESA’s Meerkat and NASA’s Scout predicted a potential impact.

https://www.esa.int/Space_Safety/Planetary_Defence/Asteroid_2024_RW1_impact_ESA_analysis

Astronomers around the world, including those from ESA’s Near-Earth Object Coordination Centre, began to track the asteroid, submitting new observations to the Minor Planet Center until the object entered Earth's shadow just 37 minutes before impact.

Thanks to their efforts, the time and location of the impact was predicted to within approximately 0.1 seconds and 100 meters.

The asteroid, which received the official name 2024 RW1 a few hours before impact, was between one and two meters in size.

How it is reported in the media -

https://www.atlasobscura.com/articles/luzon-asteroid-2024-rw1

https://www.space.com/asteroid-earth-impact-september-2024-rw1
https://www.livescience.com/space/a...-philippines-8-hours-after-it-was-1st-spotted

https://en.wikipedia.org/wiki/2024_RW1 (I'm guessing more details to follow)


I had an interesting discussion with colleagues about what constitutes 'space weather'. The solar wind and GCR are obvious, and perhaps to space 'dust' and micrometeoroids. However, what is the limit/boundary with respect to asteroids or meteorites, to be included in 'space weather' or as separate entities. There is also 'space junk' to be concerned about in orbit.

 

[berkeman]

I didn't realize we had these:

Within minutes of discovery, automatic asteroid warning systems such as ESA’s Meerkat and NASA’s Scout predicted a potential impact.

Sounds a bit ominous...

 

[Vanadium 50]

I didn't realize we had these:

Oh yes.

Think about it - if there was a flash of light and now Boise (or Nanjing, or Qom or Osaka, or...) was missing, people would want to know if this was an impact or something more nefarious.

 

[berkeman]

Yeah, good point. Do all the nations with nuclear weapons subscribe to the notification list? (Although, I guess the notifications could be spoofed in the case of a first strike attack... I need to go curl up in a ball somewhere for a while).

 

[Vanadium 50]

I don't know who has access to what information and when. I suspect exact capabilities are not public. I suspect there are multiple different methods of monitoring used, and conclusions would need to be consistent with all of them.

Hiroshima-sized impacts occur roughly once a decade. Of course, most are over ocean, ice caps or otherwise underpopulated regions.

 

[Vanadium 50]

I looked it up - Luzon is the 4th most populous island in the world.

 

[Nugatory]

Skimming the news articles….
About one meter in diameter so maybe 250kg, speed 17 km/sec. $mv^2/2$ looks like about $10^{13}$ joules, a ton of TNT is about $4\times 10^9$ joules so we're talking kilotons here (and are very happy that these things generally dissipate their energy in the atmosphere).

 

[davenn]

I have not heard of any confirmed meteorites on the ground being recovered
A few unconfirmed reports tho.

 

[Vanadium 50]

I have not heard of any confirmed meteorites on the ground being recovered

Do you expect any? The impact was several km out to sea.

I am going by the articles, which is probably unsafe, as they seem to think Luzon is the northernmost island in the chain. Ten seconds with Google would show otherwise.

 

[davenn]

Do you expect any? The impact was several km out to sea.

General indication was that the remains passed east to west across the northern end of Luzon.
They most likely ended up in the sea off the west coast of the region.

as they seem to think Luzon is the northernmost island in the chain.

Yes, it is the northern most island ... long and skinny and full of volcanoes.
I have a couple of tektites from northern Luzon and a meteorite from southern Luzon,
it's called Bondoc.
My wife, who is over there at the moment, she comes from one of the southern islands called Panay

Dave

 

[Vanadium 50]

Yes, it is the northern most island

No, it is not. It is in the north. It is not the northernmost.

The maps I have seen show it going west to east, but still ending up in the water.

 

[berkeman]

passed east to west

west to east

Remember, Dave is in Australia, so, you know...

 

[Vanadium 50]

To be honest, I do not trust the press got the direction right. I don't think they care. They get the same number of clicks if they get the facts right or not, so why bother?

 

[davenn]

No, it is not. It is in the north. It is not the northernmost.

It's the main northern most island .... there's only a couple of dots to the north of it
then ya get to Taiwan

To be honest, I saw that it had entered the atmosphere east of nthrn Luzon and then seeing the path plots
I had then assumed it had travelled to the west and over Luzon. ... I may be incorrect in this. I have searched high and low and have not found any specific reference to direction of travel.

This graphic from ESA gives a predicted indication that it's travelling NW towards SE and doesnt even cross Luzon compared to some of the earlier graphics.

This graphic shows where some of the visual observations and videos were done from ....

cheers
Dave

 

[Vanadium 50]

It's the main northern most island .... there's only a couple of dots to the north of it

That's a little like "Adelaide is the southernmost city in Australia. I mean there is Hobart, but who cares about Hobart?"

I would not be surprised if the reporters saw the track and half guessed it was moving one way and half guessed the other.

In any event, if its path was over water, it does not bode well for recovering any bits of it.

It might also be worth pointing out that if it came in on a slightly different path, it would have been in shadow the entire time and there wouldn't have been 10 hours of warning.