Asteroid 2004 VD17 is upgraded to Torino Scale 2

[silylene old]

<font color="yellow">On 6 Feb. 2006, for only the second time in risk monitoring history, 2004 VD17 was raised to a Torino Scale rating of 2 (for "a somewhat close but not highly unusual pass near the Earth ... an actual collision is very unlikely"). </font> Today both the NEODYS CLOMON monitoring program, and JPL's NEOPO SENTRY program have upgraded the asteroid's Palermo Scale warning (however JPL is maintaining it at Torino Scale 1).<br /><br />Based upon the latest orbital observations the danger rating of this asteroid was increased to Torino Scale 2, and Palermo Scale -0.55. This is only the second asteroid to ever get this level of danger warning.<br /><br />The orbit of 2004 VD17 is rather well understood, with 456 arc days of observations, and so the error bars are small. Prior to the most recent observations, it had been rated Torino Scale -1.<br /><br />The closest approach is 4 May 2102 in the afternoon EST. The collision probability is 1 in 2780. The object diameter is estimated to be 0.57 km.<br /><br />http://www.hohmanntransfer.com/news.htm<br />http://newton.dm.unipi.it/cgi-bin/neodys/neoibo?objects:2004VD17;risk<br />http://neo.jpl.nasa.gov/risk/2004vd17.html<br /><br /><i>Based on 729 optical observations (of which 1 are rejected as outliers)<br />from 2004/11/07.385 to 2006/02/06.551.<br /><br />NOTE: The Virtual Impactor in 2102/05/04.894 in the table above is rated as Torino Scale 2.<br /> The search for VIs has been extended to 2105 to crosscheck the results obtained by Sentry.<br /><br />Coordinates are given on the Target Plane<br />Unit is one Earth radius, but impact cross section<br />has radius between 1.17 and 1.17 Earth radii<br /><br /></i><br /> <div class="Discussion_UserSignature"> <div class="Discussion_UserSignature" align="center"><em><font color="#0000ff">- - - - - - - - - - - - - - - - - - - - - -</font></em> </div><div class="Discussion_UserSignature" align="center"><font color="#0000ff"><em>I really, really, really miss the "first unread post" function.</em></font> </div> </div>

 

[mlorrey]

I wouldn't freak. Apophis, the other hair raiser, was raised to a Torino Scale 4 before more data came in. It went down to a 0 for a bit and is now a 1.<br /><br />Someone should name one of these asteroids "Chicken Little".

 

[silylene old]

I don't "freak". I just enjoy the near earth asteroid searches and have followed them ever since they have been posted to the internet. <br /><br />Apophis reached Torino Scale 4 based upon quite limited data on its orbital arc. However this isn't the case this time. 2004 VD4 has a very long orbital arc with about 700 observations. (btw, new Apophis data was acquired a week ago. I am awaiting the new orbital calculations based on that data - the last few observations/orbital recalculations have decreased its TS somewhat)<br /><br />Fortunately, the odds are a longshot that we are in danger (1 in 2780). And all of us will be dead then anyways. <div class="Discussion_UserSignature"> <div class="Discussion_UserSignature" align="center"><em><font color="#0000ff">- - - - - - - - - - - - - - - - - - - - - -</font></em> </div><div class="Discussion_UserSignature" align="center"><font color="#0000ff"><em>I really, really, really miss the "first unread post" function.</em></font> </div> </div>

 

[mikeemmert]

Question, silylene - since you have a lot of experience with these - do you think it was an asteroid or a comet that destroyed the dinosaurs?<br /><br />In other words, with the number of asteroids known, are there enough of them to account for a planet destroying impact every 26 million years? I'm not asking you to accept Raup and Sepkoski's work, I know it needs backup evidence, but do you think the danger comes from the inner, middle, or outer solar system?<br /><br />And don't say North Korea!

 

[thalion]

Good post.<br /><br />The JPL NEO data is incredible--if I read it correctly, it will pass within .4 Earth radii from the surface? Imagine the sight--easily bright enough to be visible in broad daylight!<br /><br /><--Also interested in seeing future orbital simulations and refinements.

 

[tony873004]

I couldn't find any data on VD4, at least not vector data, the kind I can use. Even if they had it, they probably wouldn't have vectors for the 22nd century, and there's too much chaos for me to accurately propogate it that far.<br /><br />Apophis. I didn't know they had new data aquired last week. So I queried for it. The latest solution is from January 26th. I'm not sure if this reflects the update you're referring to.<br /><br />But here's a comparison between Jan 26th's estimate and an estimate from about 6 months ago.<br /><br />The first image (April 13, 2029) shows both estimates passing through an orbit traced by a geosynchronous satellite. The further one is the Jan 2006 estimate.<br /><br />The 2nd image (2036) illustrates what is meant by "the keyhole". The slight difference in the trajectories in the first image translates into this huge difference in the 2nd image. They're on opposite sides of Earth, implying that the keyhole to a 2036 Earth impact lies inbetween the two trajectories traced in the first image.<br /><br />But I am trusting that despite the chaos, that I'm accurately propogating these orbits 7 years into the future. The positioning accurate may not be great, but it still illustrates how such a small difference can expand into a huge difference a few years later.<br /><br />http://orbitsimulator.com/BA/apophis1.GIF<br />http://orbitsimulator.com/BA/apophis2.GIF <br /><br />btw... BQ6 had some Feb 6 data. It is basically on top of the Jan 31 trajectory, unconverging a bit. I'll post a new image in that thread if it gets more dramatic than this.

 

[silylene old]

yes, I was referring to the 26 January estimate. I don't think the Apophis trajectory results have been recalculated, published, and updated the Torino Scale for a collision chance in 2036 (that's the dangerous year, IIRC!). <div class="Discussion_UserSignature"> <div class="Discussion_UserSignature" align="center"><em><font color="#0000ff">- - - - - - - - - - - - - - - - - - - - - -</font></em> </div><div class="Discussion_UserSignature" align="center"><font color="#0000ff"><em>I really, really, really miss the "first unread post" function.</em></font> </div> </div>

 

[tony873004]

Yes, 2036 is the dangerous year. The 2nd image in my post shows the 2036 passage.

 

[silylene old]

New data in on 2004 VD17 has refined the trajectory knowledge with 472 days of observaton, and increased the risk scale further, and is now ranked at Torino Scale 2 for both JPL NEODYS and CLOMON.<br /><br />Palermo Scale is now -0.4, with a collision risk of 1 in 1850.<br /><br />http://neo.jpl.nasa.gov/risk/ <div class="Discussion_UserSignature"> <div class="Discussion_UserSignature" align="center"><em><font color="#0000ff">- - - - - - - - - - - - - - - - - - - - - -</font></em> </div><div class="Discussion_UserSignature" align="center"><font color="#0000ff"><em>I really, really, really miss the "first unread post" function.</em></font> </div> </div>

 

[silylene old]

More observational data in, and JPL (CLOMON system) has slightly increased the danger in the year 2102 again (from Palermo scale -0.38 to -0.33).<br /><br />Years.........VI........PS.......Cum PS..Max TS.......ArcDays <br />2089-2104...6......-0.33......-0.33.....2..............475.054 <br /><br />VI = number of potential collision solutions<br />PS = Palermo Scale rating<br />Cum PS = cumulative PS<br />Max TS = Torino Scale rating<br />ArcDays = number of observational days from which the trajectory was claculated <div class="Discussion_UserSignature"> <div class="Discussion_UserSignature" align="center"><em><font color="#0000ff">- - - - - - - - - - - - - - - - - - - - - -</font></em> </div><div class="Discussion_UserSignature" align="center"><font color="#0000ff"><em>I really, really, really miss the "first unread post" function.</em></font> </div> </div>

 

[mlorrey]

Excellent work. What, btw, will the velocity be of Apophis when it passes within GEO altitude? This seems like an excellent opportunity to capture it into Earth orbit. Do we have any idea of its mass and composition?<br /><br />I mean, this will be 2029, we should have the orbital assets in space by then to attempt this sort of project responsibly. I can see all sorts of uses for Apophis. Beyond just mining it, it could be used as a counterbalance for a space elevator, a location to set up a GEO base with enough mass to build radiation shelters in to protect crews against solar flares and mass ejections. <br /><br />This could even be sold to the people of Earth as a mission to protect Earth from this asteroid by "getting it under control". Given its name, this should be good for a lot of positive spin on a capture mission.

 

[llivinglarge]

What about using 3753 Cruithne or 2002 AA29 as a shield?

 

[silylene old]

The 2004 VD17 close pass has finally been picked up by the media:<br />http://news.yahoo.com/s/afp/20060302/sc_afp/spacescienceasteroids_060302160347<br /><br /><font color="yellow"><b>2102 space rock to give Earth its closest shave Thu Mar 2, 11:03 AM ET</b><br /> <br /><br />PARIS (AFP) - A space rock capable of sub-continent scale devastation has about a one in 1,000 risk of colliding with Earth early next century, the highest of any known asteroid. <br /><br />The rock, 2004 VD17, is about 500 metres (yards) long and has a mass of nearly a billion tonnes, which -- if it were to impact -- would deliver 10,000 megatonnes of energy, equivalent to all the world's nuclear weapons.<br /><br />Spotted on November 27 2004, VD 17 was swiftly identified as rock that potentially crossed Earth's orbit, with a 1 in 3,000 risk of collision on May 4 2102.<br /><br />Further observations and calculations have prompted the risk on that day to be upgraded to "a bit less than 1 in 1,000," said NASA Near-Earth Object (NEO) expert David Morrison in an emailed circular.<br /><br />"The risk of an impact within the next century (is) higher than that of any other known asteroid," he said, stressing however that the likelihood of a hit was small.<br /><br />"Fortunately, it is nearly a century before the close pass from VD 17. This should provide ample time to refine the orbit and, most probably, determine that the asteroid will miss the Earth."<br /><br />VD 17, which was previously categorised as a grade green ("merits careful watching") on the Torino scale of NEO hazards, has been upgraded to grade yellow, "meriting attention."<br /><br />There are two more grades beyond this, orange ("close encounter") and red ("collision is certain"), involving objects capable of inflicting regional or global devastation.<br /><br />The asteroid's closest proximity to Earth on the 2102 flyby was not given by Morr</font> <div class="Discussion_UserSignature"> <div class="Discussion_UserSignature" align="center"><em><font color="#0000ff">- - - - - - - - - - - - - - - - - - - - - -</font></em> </div><div class="Discussion_UserSignature" align="center"><font color="#0000ff"><em>I really, really, really miss the "first unread post" function.</em></font> </div> </div>

 

[silylene old]

New observational data came in yesterday from La Silla in Chile and from Spacewatch 1.8m scope in Arizona. The data has been analyzed by both JPL's NEOPO, and by NEODYS's CLOMON software. Currently 692 observations of VD17 have been taken over a span of 480 days, so the trajectory is being increasingly refined.<br /><br />The danger level has been increased from paelrmo Scale -0.33 to Palermo Scale -0.28 . Torino Scale remains at "2".<br /><br />The impact risk has been increased to 1 in 1410.<br /><br />This asteroid needs watching !<br /><br /><br /><br /> <div class="Discussion_UserSignature"> <div class="Discussion_UserSignature" align="center"><em><font color="#0000ff">- - - - - - - - - - - - - - - - - - - - - -</font></em> </div><div class="Discussion_UserSignature" align="center"><font color="#0000ff"><em>I really, really, really miss the "first unread post" function.</em></font> </div> </div>

 

[jatslo]

silylene: "... <font color="yellow">This asteroid needs watching</font>..."<br /><br />Where there is one, there is likely another. <img src="/images/icons/smile.gif" /> Astronomical observations in this matter should be of the greatest importance to all Earth inhabitants in my opinion, but unfortunately, this is not the case. If I remember correctly, Australia is one nation who does not take this real threat seriously; care to name another?<br /><br />Thanx for the update!!!

 

[mlorrey]

While the US DoD is treating asteroids as a threat in its purview, I wouldn't worry about the Australians much. A country has to have ballistic capability to do anything about it anyhow, and it seems from up here that Australia's defense strategy is primarily keeping China and North Korea more pissed at the US, than in building anything either country would see as a threat to justify building more missiles or targeting them at Australia.

 

[jatslo]

... eyes in the sky ... is what I was talking about; deflection, annihilation is another matter. <img src="/images/icons/wink.gif" /> There are far fewer 6 kilometer asteroids, so they say, but them other ones are a dime a dozen. .5 kilometer ones strike every 100-years, or something to that effect. I am just guessing by the way.

 

[silylene old]

Let us remember that on March 16, 2880 (yes, 874 years from now) <b>Asteroid 1950 DA</b> has a 1 in 300 chance of hitting the Earth, with a Palermo Scale = +0.17 , which is the highest danger ranking of any known asteroid. This asteroid's trajectory is very well understood, with over 56 years of observational data. The most recent observation, from Desert Moon Observatory in New Mexico in January 2004 confirmed no change has occured in this asteroid's previously calculated trajectory from 2001.<br /><br />Here is a very interesting summary of what is known about Asteroid 1950 DA, and links to several technical papers describing estimations of its long term trajectory and error analysis: http://neo.jpl.nasa.gov/1950da/ The error analysis this far into the future is problematical, as the Yarkovsky effect is incompletely understood and the Solar radiation pressure can be variable, depending upon the sun's activity.<br /><br />A recent paper and simulation (available in the link above) makes this estimate of the result if Asteroid 1950 DA hit the Atlantic Ocean:<br /><font color="yellow"> It was found waves propagate throughout the Atlantic Ocean and the Caribbean. Two hours after impact, 400-foot waves reach beaches from Cape Cod to Cape Hatteras. Four hours after impact, the entire East Coast experiences waves at least 200 feet high. It takes 8 hours for the waves to reach Europe, where they come ashore at heights of about 30 to 50 feet. <br /></font><br /><br /> <div class="Discussion_UserSignature"> <div class="Discussion_UserSignature" align="center"><em><font color="#0000ff">- - - - - - - - - - - - - - - - - - - - - -</font></em> </div><div class="Discussion_UserSignature" align="center"><font color="#0000ff"><em>I really, really, really miss the "first unread post" function.</em></font> </div> </div>

 

[tony873004]

This thing did just get a bit closer.<br />http://www.orbitsimulator.com/BA/2004vd17.GIF<br />My graphic says Mar 1 estimate. It should say Mar 5 instead.

 

[silylene old]

Two more observatories have made new measurements of 2004 VD17, which have extended the measure trajectory to 697 measurements over 483 days.<br /><br />Unfortunately with the new data, both JPL and NEODYS orbital calculations show an increased risk. The Palermo Scale has been increased to -0.26 (Torino Scale = 2). The probability of collision has been increased to 1 in 1,330. <div class="Discussion_UserSignature"> <div class="Discussion_UserSignature" align="center"><em><font color="#0000ff">- - - - - - - - - - - - - - - - - - - - - -</font></em> </div><div class="Discussion_UserSignature" align="center"><font color="#0000ff"><em>I really, really, really miss the "first unread post" function.</em></font> </div> </div>

 

[astroguard]

<blockquote><font class="small">In reply to:</font><hr /><p><b>silylene</b> wrote: <i>The probability of collision has been increased to 1 in 1,330</i><p><hr /></p></p></blockquote>It's been further increased to one in 1280, and with an impact energy of 14,000 megatons TNT, it should merit some concern.

 

[silylene old]

Also interestingly, more historic photographic data of VD17 was discovered. When this data is entered into the calculations, I expect we may see a significant revision in the asteroid's trajectory.<br /><br /><i>The DOU MPEC of 12 March 2006 reported three positions from Sergio Foglia, Giuseppe Forti, and Maura Tombelli using archive images from NEAT's Mt. Palomar telescope from 16 Feb. 2002, tripling 2004 VD17's observation arc from 487 to 1,482 days. This data was supplanted in the next DOU MPEC with two positions calculated from the 16 Feb. 2002 archive images, and three positions were added from 14-15 March 2002, all coded as "very faint images." This new data was submitted to the MPC by Rob Matson, who told A/CC that, even though "these five points are pretty self-consistent," they are "basically at the noise floor" for NEAT/Palomar images. </i> <br /><br />archive VD17 images from 2002: http://asteroidi.uai.it/pub/swap/k04v17d.htm <div class="Discussion_UserSignature"> <div class="Discussion_UserSignature" align="center"><em><font color="#0000ff">- - - - - - - - - - - - - - - - - - - - - -</font></em> </div><div class="Discussion_UserSignature" align="center"><font color="#0000ff"><em>I really, really, really miss the "first unread post" function.</em></font> </div> </div>

 

[mlorrey]

One thing to keep in mind is that the odds of impact are cumulative for all expected close passes. VD17 has only 2 projected close passes. Apophis has 3, while most others high on the Palermo scale have many more passes to accumulate a high cumulative odds of striking.<br /><br />Thus the odds for VD17 hitting on either individual pass is much higher than of Apophis doing so.<br /><br />And, no, jatslo, half km objects don't impact every century. Tunguska was 30-60 meters in diameter. There have been maybe 2 other bolides of similar size in the last century. Thus, odds for once a century impacts have a size range of 100-150 meters at most. 500 meters would be once every 1,000-5,000 years, most likely.<br /><br />The larges bolide impact discovered yet dating to the Holocene was the 1422 impact off the coast of New Zealand: <br />http://en.wikipedia.org/wiki/Mahuika_crater

 

[cosmictalk]

We should spend more energy into world defenses against threats from outer space! <br /><br />If all we have for a defense is an idea using gravity to push from a small space craft, painting the surface or piling tons of dirt on a astroid and we have not even done tests on these thoeries we are way behind in our defenses!<br /><br />and so far there are no defenses against solar waves (flares) destroying our technological advances that could leave us defenseless.

 

[silylene old]

<font color="yellow">Also interestingly, more historic photographic data of VD17 was discovered. When this data is entered into the calculations, I expect we may see a significant revision in the asteroid's trajectory. <br /><br />The DOU MPEC of 12 March 2006 reported three positions from Sergio Foglia, Giuseppe Forti, and Maura Tombelli using archive images from NEAT's Mt. Palomar telescope from 16 Feb. 2002, tripling 2004 VD17's observation arc from 487 to 1,482 days. This data was supplanted in the next DOU MPEC with two positions calculated from the 16 Feb. 2002 archive images, and three positions were added from 14-15 March 2002, all coded as "very faint images." This new data was submitted to the MPC by Rob Matson, who told A/CC that, even though "these five points are pretty self-consistent," they are "basically at the noise floor" for NEAT/Palomar images. </font><br /><br />The eight observations from 2008, plus some new observations ahve been added to the trajectory calculation. The trajectory has now been measured with 719 observations spanning 1492 days, which is about three times longer than previously. So now the trajectory is now defined with much better accuracy.<br /><br />VD-17 remains a risk, at Torino Scale = 2. The Palermo Scale has been decreased slightly to -0.38. The possibility of a collision with Earth in 2104 has been eliminated, and only the possible collision in 2102 remains.<br /><br />The chance of collision is currently estimated to be 1 in 1,790. The energy of that collision, if it occurs, is estimated to be about 14,500 MT, enough to cause subcontinental destruction.<br /><br />More observational data is needed, but given the current accurate knowledge of the asteroid's orbit, I don't expect much revision of the trajectory will occur until several years of additional data is acquired.<br /><br />Nothing to panic about, but let's keep watching.<br />http://neo.jpl. <div class="Discussion_UserSignature"> <div class="Discussion_UserSignature" align="center"><em><font color="#0000ff">- - - - - - - - - - - - - - - - - - - - - -</font></em> </div><div class="Discussion_UserSignature" align="center"><font color="#0000ff"><em>I really, really, really miss the "first unread post" function.</em></font> </div> </div>