Risky asteroid 2009 WM1(Nov 2009)

[MeteorWayne]

Re: Risky asteroid 2009 WM1

Not really. Every observation has errors in position of various sizes. There are thousands of potential orbits that pass through all those observation circles. The nominal orbit is a "best fit" to all the observations. If a new set has a postion off to one side of the nominal orbit, it can increase the overall uncertainty. this is especially true with short observation periods such as this asteroid with obs over only 6 days. The orbit is quite uncertain at this time.

 

[MeteorWayne]

Re: Risky asteroid 2009 WM1

JPL Sentry has updated.

Cumulative PS -0.96 impact risk 1 in 5260

2018 PS -1.24 (1 in 19K)
2027 PS -1.45 (1 in 15K)
2032 PS -1.89 (1 in 32K)

116 VI's between 2018 and 2106.

MW

 

[silylene]

Re: Risky asteroid 2009 WM1

wow, PS = -0.96 !

Isn't this asteroid now the second highest PS we have seen since the monitoring program has begun ? (For a brief time around Christmas 4 or 5 yrs ago, Apophis had a higher PS risk rating; about +0.5 as I recall, and its Torino was briefly set at 4).

 

[cyclonebuster]

Re: Risky asteroid 2009 WM1

Cyclonebuster: I noticed you used iron for density, when the current best guess is that it's dense rock. Using dense rock also gets a pre-atmospheric energy match with the Impact Risk assessment (of course they are all just guesses based on albedo and could be way off). I recalculated, and about 50 miles out you're pretty safe, but that still means about 7,853 square miles of devastation for one 208m hunk of rock...

I am curious though, the impact effects program gives some weird results for ejecta. For instance, if you put in a distance of only 5 miles away, the mean ejecta thickness is 11.6ft, but the mean fragment diameter is 72.8ft. So, does that mean a few big rocks with lots of space to dodge them? :? (assuming you didn't spontaneously combust from the irradiance or get seriously tossed about by the sesmic and wind events...)

I assumed most of them are iron. If it is another material the effects would be less given the same information. But I wouldn't want to be anywhere near this if it were to hit. You must be at least >50 miles from this thing unless it hits the ocean then you would not want to be near the coast at all. I don't like what is already happening with this asteroid. The chances of impact are getting greater with more solutions as they run them.

 

[R1]

Re: Risky asteroid 2009 WM1

How did it get your initials, MeteorWayne?
I mean what does WM1 stand for? Will they give it a real name like they gave Apophis?

 

[grokme]

Re: Risky asteroid 2009 WM1

Interesting thread. I'm enjoying reading it. So how long do they observe it before they can say definitively what the risks are?

 

[ainu7]

Re: Risky asteroid 2009 WM1

Hi folks, I'm not an expert in this area, but have interest about asteroid impacts since some years ago...

My daily routine when interesting object emerges: checking MPEC to see if there are new observations, visiting NeoDyS to get relevant files, and running orbfit to calculate impact probability before NeoDyS publish it.

NeoDyS just updated their impactor table. (and it gives similar result as mine, andd I owe them this pleasure, yeah..)

2018 : prob 1/11000, PS -1.02
2027 : prob 1/9550, PS -1.26
2032 : prob 1/170000, PS -2.62

nominal orbit nearer from 2018/2027 solution but farther from 2032 solution, so probability changed in that way.
Also there are more virtual impactors than yesterday, 165 vs. 116.

Cumulative prob = 1/3930
Cumulative PS = -0.79

I don't have too much belief on exact probability for many reasons, especially if it's very small (i.e, lower than 1/100), but I think this object is worth looking on for next several days.


grokme: Depends on risks. Higher the risks, more time needed to refine the orbit to eliminate impact probability.

 

[F111F]

Re: Risky asteroid 2009 WM1

Looks like 2009WM1 is one for the history books...it disappeared from the Sentry Risk Table this morning...

 

[silylene]

Re: Risky asteroid 2009 WM1

Looks like 2009WM1 is one for the history books...it disappeared from the Sentry Risk Table this morning...

2009WM1 is missing from the Sentry Risk Table...however, it is not included in the "Sentry Risk Removed Table" either! Odd. See http://neo.jpl.nasa.gov/risk/removed.html

2009WM1 is still on the NEODyS risk page.

 

[lekszikov]

Re: Risky asteroid 2009 WM1

No, I'm affraid its just an update error. Risk goes upp again On neodys 1/10000 in 2018 and 2027.
I hope it will gone, but not yet.

But the moid is increased... Explain it Wayne , pls?

 

[MeteorWayne]

Re: Risky asteroid 2009 WM1

That's highly unusual. It is not on the removed objects list, which leads me to believe this is the relevant line:

" Whenever a potential impact is detected it will be analyzed and the results immediately published here, except in unusual cases where an IAU Technical Review is underway."

About an IAU Technical Review:


http://web.mit.edu/rpb/wgneo/TechComm.html

"The procedure for technical review is as follows. Information leading to an impact prediction, consisting of an evaluation of the case and all data and computational details necessary to understand and reproduce the studies carried out by the authors, should be transmitted for confidential review to the chair of the IAU Working Group for Near Earth Objects (WGNEO), the President of IAU Division III, the General Secretary of the IAU, and the members of the NEO Technical Review Team (see below), before any announcement and/or written document on the subject be made public via any potentially nonprivate communication medium, including the World Wide Web. The individual members of the NEO Technical Review Committee shall review the work for technical accuracy and shall communicate under most circumstances within 72 hours the results of their reviews to the chair of the WGNEO and directly to the authors of the report or manuscript.

The authors of the work are encouraged to refer to this IAU review and may quote this review if and when they choose to make a public release of their conclusions. If the consensus of the above review supports the conclusion that there is a significant impact risk meriting an announcement by the IAU itself, such an announcement will be posted on the IAU webpage http://www.iau.org/ for public access as soon as possible after the information is released by the authors to the public. If the review disagrees with the original analysis or if there is not a consensus among the reviewers, the confidential results of the review will be given to the authors so they can revise or improve their work, as they see fit."

 

[silylene]

Re: Risky asteroid 2009 WM1

Ainu7, good to hear from you, and I hope you decide to become a regular contributor on our SDC forums. Many of us here enjoy watching the near-earth asteroids. We have had quite a few good threads and discussions on these subjects over the years, I think you will enjoy.

 

[silylene]

Re: Risky asteroid 2009 WM1

That's highly unusual. It is not on the removed objects list, which leads me to believe this is the relevant line:

" Whenever a potential impact is detected it will be analyzed and the results immediately published here, except in unusual cases where an IAU Technical Review is underway."

About an IAU Technical Review:
.....

MW, very interesting !! I knew it was odd and unusual when the asteroid disappeared off both the risk and the risk-removed page. I have never seen this happen before.

 

[ainu7]

Re: Risky asteroid 2009 WM1

There could be some possibilities regarding disappearance of 2009 WM1 from JPL page.

(1) Prediscoveries were discovered.

I checked recent MPECs but there weren't any new one mentioning this object's observation.
But it could be possible that JPL has their old observation, not made public, and this data could be used to calculate more refined orbit and eliminate impact odds.

Also, the orbit of this asteroid is very uncertain and preliminary. I don't think there could be search of prediscoveries yet, uncertainty is more than tens of degrees when you try to find them in old archives.

(2) They are in the review process indeed.

Well, I think there was a technical review when PS of Apophis(2009 MN4) went over 0.00, however in that case, previous assessment was still in the homepage meanwhile.

Also, there were several occasions when PS of asteroids was -0.xx, and I think their probability was updated as same as other 'normal' objects having PS -2 or -3. - So I think it's rather unlikely that there is a technical review this time as the situation isn't unusual yet.

(3) JPL page is just being updated.

So this is my opinion, as I think (1) and (2) are unlikely.



silylene: I enjoyed those threads in real-time indeed for many years, including Apophis and this summer's 2009 KK

 

[MeteorWayne]

Re: Risky asteroid 2009 WM1

Well, I certainly can see what has changed!

Looking at the 2017 close approach, several things have vastly increased the risk.

One is, the date of close approach from the nominal orbit, which was Nov 12 yesterday is now Nov 23!

The node of the orbit (when it crosses the plane of the earth's orbit; this is the only time a collision can occur) was Nov 16th, today it is Nov 23rd, only about 4 hours before close approach.

Close approach distance (~0800 UT 2018 Nov 23) was 83x LD yesterday; today it is 0.0062 AU or only 2.4 times Lunar Distance.

So the new orbital data, while slightly moving the EMoid away (from 0.0041 to 0.0048 AU), has shifted the timing so that the earth and the asteroid will be almost at the same spot at the same time. It should be interesting to see the resuly of the IAU Technical review.

For the reasons stated, I believe one is underway.

From what I can tell the arc is only increased to 7 days, so I don't suspect and prediscovery obs. (55 obs, 7 days vs 49 obs, 6 days yesterday.

Next I'll take a look at the 2027 encounter.

 

[MeteorWayne]

Re: Risky asteroid 2009 WM1

2027 encounter CA has increased to 0.59 AU..very far away on Dec 21, with nodal crossing on Dec 13th. Only the still high uncertainty in the orbit (residuals .5076) are keeping that a high risk event.

 

[MeteorWayne]

Re: Risky asteroid 2009 WM1

How did it get your initials, MeteorWayne?
I mean what does WM1 stand for? Will they give it a real name like they gave Apophis?

The Preliminary designation consists of the year of discovery (2009), it was discovered during the last two weeks of November (W); M1 means it was the 37th object discovered during that 2 week period.

Therefore 2009 WM1


The next step is for it to get a permanent Minor Planet number, that takes months or years. The current highest permanent number I've seen is 228,225. These are only issued when the orbit is well determined.

After that, a name can be proposed to the IAU.

 

[silylene]

Re: Risky asteroid 2009 WM1

Well, this exciting thread has moved to the top of the Google search list for 2009WM1 (just like asteroid 2009KK did). Expect to welcome a big influx of new visitors to the forum in the next week, which is good news !

Geesh, and we all thought the initial WM1 = WayneMeteor1 :lol:

 

[MeteorWayne]

Re: Risky asteroid 2009 WM1

Wait till this puppy hits the mainstream media!

The IAU Review process is supposed to take place in less than 72 hours, so the clock is ticking.

 

[lekszikov]

Re: Risky asteroid 2009 WM1

Wayne !

So i'm in panic..
How could it be... 0.118->0.2xx->0.018 in close aproach? Error bar?

 

[CalliArcale]

Re: Risky asteroid 2009 WM1

This is a very exciting and interesting thread; I wasn't expecting the data for 2009 WM1 to take this turn. Of course, we don't need to worry about 2027, since the world will end in 2012. (Just kidding.) But I await the IAU's review with eager anticipation.

 

[MeteorWayne]

Re: Risky asteroid 2009 WM1

Wayne !

So i'm in panic..
How could it be... 0.118->0.2xx->0.018 in close aproach? Error bar?

First of all, as the cover to The HitchHiker's Guide to the Universe says:

DON'T PANIC!

For one thing, this is preliminary data, and a very rough orbital determination. If you look through the 2009 KK thread (which I bumped for some historical perspective) a 7 day measurement arc is nothin' There is still much uncertainty.

Second, I have no idea of what the numbers you are using are, or where they are from. Please specify where you are getting them and what they represent.

 

[MeteorWayne]

Re: Risky asteroid 2009 WM1

Just for reference, the peak PS (Palermo Scale) risk for 2009 KK was -1.09. This object has already exceeded that.

 

[lekszikov]

Re: Risky asteroid 2009 WM1

that's why im in panic... :?

 

[MeteorWayne]

Re: Risky asteroid 2009 WM1

A PS of -1 means that the risk for 2009 WM1 is 10 times LESS than the background risk of an asteroid smacking us at any time.

So DON'T PANIC!