Asteroid 2006SU49 in the year 2029 - needs a close watch!

[MeteorWayne]

Actually, with the new prediscovery images that were found, it's going to be pretty accurate.<br />Well have several more chances to refine the estimate before then.<br /> <div class="Discussion_UserSignature"> <p><font color="#000080"><em><font color="#000000">But the Krell forgot one thing John. Monsters. Monsters from the Id.</font></em> </font></p><p><font color="#000080">I really, really, really, really miss the "first unread post" function</font><font color="#000080"> </font></p> </div>

 

[alokmohan]

But within this period we will discover new asteroids,KBOs ,then?

 

[MeteorWayne]

I'm sure we will.<br />As has been stated, the real danger is not the ones that we can see, we know where they are, and where they are going.<br />THe real danger is the ones that come out of the sunside that we don't see coming.<br />Or a comet approaching too fast for us to do anything about it, but duck.<br /><br />IIRC, 2004 FU162 was one of those that we didn't see until it was already past us.<br /><br />KBO's are no danger to us if they're in the Kuiper Belt <img src="/images/icons/smile.gif" /><br /><br /> <div class="Discussion_UserSignature"> <p><font color="#000080"><em><font color="#000000">But the Krell forgot one thing John. Monsters. Monsters from the Id.</font></em> </font></p><p><font color="#000080">I really, really, really, really miss the "first unread post" function</font><font color="#000080"> </font></p> </div>

 

[alokmohan]

I endorse.

 

[witgenestone]

I think its a real danger wheter we discover it or not. It won't take another path out of pure discovery <img src="/images/icons/smile.gif" />.<br /><br />I'm sure if we survive long enough, and get to counting them all. There will be new threats to deal with. Don't worry.

 

[silylene old]

By far the greatest known danger is the asteroid 1950DA, which makes a very close pass in March 2888. Its orbit is known quite accurately, with over 56 years of precision observational data.<br /><br />I posted about this in March 2006, and I will repost my comments here:<br /><br /><i>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, whe</font></i> <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>

 

[oscar1]

Round about eight hundred and seventy odd years ago, William the Conqueror was born, i.e. the Englishman of today hadn't as yet formed. Since then we improved quite a bit, technologically that is. Therefore, I'll go to my grave with the fullest confidence that we will blow this 1950-DA thing to bits before it does that to us.

 

[MeteorWayne]

Well let's not get crazy here. The orbit of 1950 DA is known with high precision, but many assumptions are made for this impact (0.33% chance) to occur.<br /> It's 100 orbits + in the future, using estimates for<br />1. Solar Particle Wind (How does it change in centuries?)<br />2. Jupiter's Satellites<br />3 Galactic Wind (How does it change in centuries?)<br />4.Solar Mass loss (How does it change in centuries?)<br />5.Poynting Robertson Drag (what is the precise size, color over the surface and spin rate of the object, will it rotate at the same speed and orientation for centuries?)<br />6. Solar Oblateness (Sun twinkies?)<br />7. Sun barymetric Center relativistic shift<br />8. Only the 61 most perturbing asteroids. (How many have been discovered since 2001?)<br />9. Planetary Mass uncertainty<br />10 Solar Radiation Pressure (How does it change over centuries)<br />11. Yarkofsky effect<br />12 Numerical Integration error.<br /><br />Should any of these parameters shift even within their 1 sigma errors, with 100 orbits to work with, any precision could easily be swamped.<br /><br />Obviously, it makes no difference to any of us alive today, and I would suggest that any object 100 orbits out is well beyond what we can reasonably be able to predict with any precision.<br /><br />The Science paper was more a demonstration of technique and parameters to consider, than a hard prediction, even at the 0.33% odds.<br /><br />As I said, it only considered the 61 most perturbing asteroinds as of 2001.<br />We've discovered thousands since then, which surely shift the effects.<br /><br />Very interesting article, and something for those dozens of generations ahead to look at.<br /><br />I wouldn't tell your great,great,great,great,great,great,great,great,great,great,great,great, great, great, great, great, great, great grandkids to sell the ranch just yet <img src="/images/icons/smile.gif" /><br /><br /><br /><br /> <div class="Discussion_UserSignature"> <p><font color="#000080"><em><font color="#000000">But the Krell forgot one thing John. Monsters. Monsters from the Id.</font></em> </font></p><p><font color="#000080">I really, really, really, really miss the "first unread post" function</font><font color="#000080"> </font></p> </div>

 

[spacester]

You gotta be kidding me.<br /><br />You have the gall to tell everyone else to spell out their TLAs (Three Letter Acronyms) whilst insisting on being less than clear on your usage of units! You follow this with an unapologetic, corrosive defense of the latter when called on it, and display that rudeness in parallel with an inability to extract a TLA definition from the sentence immediately preceding it, which did indeed spell it out!<br /><br /><img src="/images/icons/rolleyes.gif" /><br /><br />Are you even familiar with the concept of contrition? <div class="Discussion_UserSignature"> </div>

 

[silylene old]

<font color="yellow">The orbit of 1950 DA is known with high precision, but many assumptions are made for this impact (0.33% chance) to occur. <br /></font><br /><br />I am glad you enjoyed the <i>Science</i> paper. It's quite good.<br /><br />You are right on all the sources of error in the trajectory calculation (I mentioned that the errors are incompletely known in my previous post). That's why the risk of collision is 1/300, and not higher a higher value - error bars. <br /><br />Given the discussion of the risks of a future asteroid collision, I thought I should make everyone aware of 1950DA. The risk from this one asteroid exceeds (by a significant amount) the cumulative risks of all other known asteroids. The good news is that we have a whole lot of time to prepare for this.<br /><br /><i>Sky and Telescope</i> this month had a very good article about the calculation of risks for potetntial earth-collision asteroids. It also had a good discussion of steps we could take to mitigate the risk, if we have sufficient time to prepare (gravitational tug). From the article's description, it didn't seem particularly difficult to subtly modify the future trajectory from a certain collsion to a miss. With 1950DA, we certainly have the time, if this becomes necessary, to prepare a diversion mission. <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>

 

[spacester]

<img src="/images/icons/rolleyes.gif" /><br /><br />Sir, did you or did you not request a spelling-out of the three letter acronym SOI, when in fact it was right there in front of your nose all the time?<br /><br />Truth or Fact?<br /><br />A simple Yes or No is desired: did you ask for something that already existed?<br /> <div class="Discussion_UserSignature"> </div>

 

[silylene old]

In the field of semiconductors, "SOI" means silicon-on-insulator. The term is very much used. <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>

 

[spacester]

The TLA (no, I'm not gonna write it out again - op. cit. <img src="/images/icons/laugh.gif" /> ) issue is one which I've tracked from my start here. <br /><br />I used to write out every single one of them without fail in my posts and often offered explanatory statements. I had hoped to lead by example but the lesson did not take. So I have relaxed my standards the last two years. There are certain ones in certain subjects that really ought to be known by those interested in the subject - and in my view the task of tracking down the definition is a reasonable "initiation requirement" for the newbie. Certainly SOI as used here is not in common usage (YET! <img src="/images/icons/laugh.gif" /> ), so I spelled it out.<br /><br />I will continue over on the Suggestions forum . . . <br /> <div class="Discussion_UserSignature"> </div>

 

[spacester]

Um actually I spelled it out on the post to introduce the TLA as of 10/07/06 09:37 AM per the html code my browser is getting. Have you still not found it then? <br /> <div class="Discussion_UserSignature"> </div>

 

[oscar1]

You are quite right where a SOI is concerned, and I have one of these bathroom brushes to tackle that Son Of an Itch!

 

[alokmohan]

ANN ARBOR, Mich. -- The first detailed images of a binary asteroid system reveal a bizarre world where the highest points on the surface are actually the lowest, and the two asteroids dance in each other's gravitational pull. <br /><br />A binary asteroid is a system where two asteroids orbit around one another, like a mini Earth-moon system, said Daniel Scheeres, University of Michigan associate professor of aerospace engineering. The new results are scheduled to appear Oct. 12 in the journal Science in a pair of papers by Scheeres and Dr. Steven Ostro of the NASA/Caltech Jet Propulsion Laboratory. <br /><br />The radar images of asteroid KW4 (the official full designation is 66391 1999 KW4) were obtained in May 2001, when the asteroid passed 4.8 million kilometers from Earth. Previously, KW4 was classified as a potentially hazardous asteroid (PHA) because of the proximity of the asteroid's orbit to Earth's orbit. The new observations show that there is no chance of KW4 hitting Earth within at least the next 1,000 years, Scheeres said. <br /><br />"The KW4 results have profound consequences for ideas about mitigation of the asteroid collision hazard," Scheeres said. <br /><br />The observations show that the larger object is spinning in its orbit so fast that it has been flattened into a kind of flying saucer shape, said Scheeres. Because of this, the mountainous region along the center of the asteroid actually forms the lowest part on the asteroid. In fact the asteroid is spinning so fast that the equatorial ridge is very close to lifting off the surface and spinning into space, he said. <br /><br />Another interesting finding is that the two bodies in the asteroid system are orbiting so closely that they are caught in each other's gravitational pull. <br /><br />"They are so close together that when one rotates it affects the other's movements," Scheeres said. <br /><br />Based on the observations, the KW4 binary asteroid appears to have formed either from tidal disruption dur

 

[silylene old]

That is interesting. The full report in <i>Science</i> will be very soon. <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>