"Mysterious light," loud explosion in Virginia Beach

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MeteorWayne

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o_rune_o":1ixfhplf said:
2004 FU162 has 963 potential impacts though. So wouldn't that mean if that's the one we're in for a few more boom booms? or am I interpreting the "Potential Impacts" column wrong? http://neo.jpl.nasa.gov/risk

The Close Approaches page also has a few coming up that are getting a tid bit close. http://neo.jpl.nasa.gov/ca/
2009 FP32 being the closest at 286,327 miles tonight.

Well, there can only be one impact, after that the object no longer exists. So in theory, only 1 of the 963 would be a real one. This is an extreme case (963 virtual impactors) due to the very short observational arc of only 44 minutes. If you look at others, you'll see the numbers are much smaller. I note that the chart has trimmed off the 2009 impacts, so now there are only 956. But even the highest rsik of those (April 1,2011) is only 1 chance in 1.8 million, so this is a very low probability event. And of course, if it was 2004 FU162 that his Sunday, like I said we'll never know unless this object is seen again, since what hit Sunday was apparently not seen before it approached.

Yes 2009 FP32 iss one of the many tiny asteroids that we now detect a day or two before closest approach, only 7.5 to 17 meters in diameter. It was first observed on the 29th, and had closest approach yesterday. It is on the risk page with 14 potential impacts between 2073 and 2104. Thise will likely decrease if more observations come in. Before the current surveys were started a few years ago, we never even would have seen it at all, due to it's small size, even at lunar distance.
 
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Smersh

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Here's something I've been wondering Wayne. With all the various "Spaceguard" centres etc around the world, tracking NEO's, what percentage of the whole sky globally is covered in total at the moment, do you think? Can you put a figure on it at all?
 
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MeteorWayne

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Not off the top of my head Smersh. I think I vaguly recall seeing a map somewhere showing the depth of coverage. The early dedicated asteroid searches concentrated near the ecliptic, since that's where most of the asteroids, and in particular, most of the threatening ones are. The more recent surveys are all sky (from their part of the world) so I imagine the whole sky is covered now.

Here's a list (with links) of the current programs;

http://neo.jpl.nasa.gov/programs/

PANSTARRS will be coming on line soon which will REALLY kick up the rate of discovery yet again, I expect.

http://pan-starrs.ifa.hawaii.edu/public/home.html
 
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Smersh

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Thanks for the links Wayne. According to the second link you gave (the Hawaii one) ...

... this mandate led to the Spaceguard Survey Report in 1992. In 1994 the House Committee on Science and Technology directed NASA, in coordination with the DOD, to work with the space agencies of other countries to identify and catalogue within 10 years the orbital characteristics of 90% of all comets and asteroids larger than 1 km and in orbits that cross the orbit of Earth ...

http://pan-starrs.ifa.hawaii.edu/public ... hreat.html

So for Earth-crossing objects larger than 1km, it looks like we should indeed have 100% coverge by now I guess. I suppose the real threat though comes from the many much smaller objects, such as whatever it was in this thread that came down near Virginia, that are not tracked, or spotted too late to do anything about would you say?

Maybe if we had several satellites with special camera lenses that can see all around (up, down, left, right) simultaneously, that might help, might it? (Or maybe we already have something like that, not sure. "Panstarrs" sounds something like that I thought.)
 
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MeteorWayne

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Well, we certainly don't have 100% coverage of 1 km NEAs yet since new ones are still being discovered, but we're pretty close. There were only 22 discovered in 2008, and only 5 so far in 2009, compared to 90 in 2000 when things really ramped up.

Before 1995: 170
1995: 9
1996: 6
1997: 12
1998: 49
1999: 56
2000: 90
2001: 67
2002: 74
2003: 55
2004: 49
2005: 49
2006: 31
2007: 28
2008: 22
2009: 8 (so far)

As far as satellite searches are concerned, it's not worth the effort and expense. There are far larger (than can be launched) dedicated telescopes here on earth that are raking in the discoveries. A satellite system would be very expensive, and gain nothing in terms of the ability to detect such objects. PANSTAARS is earth based, and has the largest CCD ever used with 1.4 billion pixels. Within a few years of it's startup, other than very long period asteroids (unlikely) we should be very close to a 100% inventory of 1 km NEAs.
 
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Smersh

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MeteorWayne":dctx3gev said:
... Within a few years of it's startup, other than very long period asteroids (unlikely) we should be very close to a 100% inventory of 1 km NEAs.

Hmmm ... sounds quite impressive but will the coverage be as good for the .5km NEAs do you reckon?

As I understand it, a 1km lump would prolly do a dinosaurs on us, but a half km lump would be pretty bad news as well wouldn't it? I'm pretty sure it would bend a few things here and there anyway. :|
 
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MeteorWayne

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Well, it won't be as good for sure, and of course there are more objects the smaller you go, but I expect the coverage will be pretty darn good. If you look at this NEA discovery chart, you can see how the large (> 1km) asteroid rate has leveled off, but the small rate is skyrocketing. An examination of the close approach charts over time shows that many we are discovering now are mostly in the very small (1-20 meter) range, there are far fewer large ones; a handful a month. this indicates that our sampling of the larger (say 0.5 km) asteroids is also becoming fairly complete.

web_total.png


And all of this is before PANSTARRS which will vastly increase the rate.

Looking at the 26 upcoming close approaches discovered in 2008 and 2009, only 2 were larger than 500 meters. 9 were 100-500 meteors, 7 50-100, and 8 less than 50 meters. Realizing that the smaller ones are much harder to find, the coverage being demonstrated is very impressive, and very few large objects are being found anymore.

MW
 
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MeteorWayne

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Another good clue is to look at the impact risk page for currently observed objects:

http://neo.jpl.nasa.gov/risk/

Note that the ones in Blue are objects smaller than 50 meters. So almost all the objects we are discovering today are very small ones. This suggests that most of the big ones have been found already. Certainly not all, but if most of the threat objects are tiny, we are doing pretty well already. the future will only get better.

This also implies that the greatest unknown in the future will soon be a newly discovered Oort cloud comet on it's first visit to the solar system. And to be honest, there's not much we could do against such an object.
 
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CommonMan

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jim48":7gwo3qwi said:
As of Monday afternoon, March 30, professor Richard Pierson, senior astronomer at Princeton University, has examined the "meteor". He is puzzled by the fact that it landed entirely intact, is made of solid metal and apparently hollow. He also reports strange noises coming from within. The landing of this object was preceded by several blasts of incandescent gas seen on the surface of Mars. Part of the object appears to be unscrewing to reveal an opening of some sort. Quite a crowd has gathered to watch. Fox News has dispatched an additional crew to the scene. CNN Science is reporting that more of the strange objects are reported down in other areas of the country as well. They are attempting to establish a link to their special consultant Dr. Clayton Forrester, the man behind the new atomic engines for his read on the phenomenon.

I am told there's one in every bunch. this must be the one.
 
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aphh

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I think it would be possible to establish the few last moments of the trajectory based on the reflection on the hood of the truck. But I'm not sure if that is necessary, it may be known already with enough precision.
 
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MeteorWayne

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Thought I'd post the from the American Meteor Society site:


On the evening of March 29, 2009, a bright fireball was witnessed over the mid-eastern seaboard. This event, with its tremendous brightness and sonic offerings is the single most reported fireball since this project was resurrected in 2005. As of April 7, 2009, 128 reports of this fireball have been received by the AMS.

The 2009 Fireball reports can be accessed here:

http://www.amsmeteors.org/fireball/fire ... ml#loglist

It is event # 212

MW
 
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Fallingstar1971

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Every weekend they have fireworks in the summer for the troops ( I don't remember if they do it in the winter, been a while since I lived there, but they really don't get snow (state WILL shut down with 1-3 inches, bases included) They cant even handle 40 degree weather without acting like its an ice age.)

Every intersection on the Ocean Streets (Atlantic and Pacific blvd) have live bands every weekend. (Summertime)

**And fireworks are LEGAL on the north shore (well you can buy them anyway, even though the police (on the south shore) classify them as bombs)) (SEE "TRUE STORY" at bottom of post)

PLUS you have THREE bases all within a stone throws of one another

PLUS you have NORFOLK (One if the US main shipyards) approx 20-25 miles away, with Newport News pretty close to that.

So there are plenty of sources for "strange lights" in the sky. Norfolk regularly takes carriers and with Oceana right there, it would not surprise me if planes were swapped off for maintenance right there and flown to the land base.

PLUS Meteor Wayne pointed out in an earlier post that the Geminiods? (I think that is right) just peaked.

Russian Rocket? Didn't we JUST go through that a couple months ago? In VB?? They have these giant Golf Ball looking things that watch the entire East coast. I don't buy that they didn't know then OR now. What I do buy is some numb nut commander not knowing what to do about it. The main shipbuilding, ship maintenance facilities are RIGHT there. Are we TRULY THAT vulnerable? Come on........(also why I have problems with , uh, "other" instances of US airspace being violated. Undetected? NO way. Unexperianced in what to do about it? MUCH more believable.) One minute it was a Soyuz rocket stage, then its a meteor, what gives?

Star

TRUE STORY

**(As I was being lectured about the fireworks, I asked why I could buy them in the same state that they are illegal, and his response was "This is a commonwealth, we do things differently then the other states. I replied that I spent most of my life in the "Commonwealth of Massachusetts and no, thats NOT how Commonwealths worked, and then the topic was changed and I was let off with a warning)

TRUE STORY
 
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