Risk from 2029 asteroid now more remote

[drwayne]

Found here:<br /><br />http://www.physorg.com/news6236.html<br /><br />The rogue rock, 2004 MN4, measures 320 metres (1,000 feet) across, making it big enough to wipe out a large city if it ever collided with Earth. <br /><br />Last December, there were a few nail-biting days when NASA calculated, from early optical observations, that the asteroid had a more than one-in-50 chance of hitting Earth on April 13, 2029. <br /><br />In addition, astronomers could not rule out a risk that the rock could in fact hit Earth, its trajectory tweaked by terrestial gravity, when it made another swing around the Sun, this time in 2036. <br /><br />But measurements using Doppler radar at the giant Arecibo telescope in Puerto Rico have progressively fine-tuned the risk, which appears to be receding, said Jon Giorgina of NASA's Jet Propulsion Laboratory (JPL). <br /><br />These calculations show that the previous estimate of the flyby, of a distance of 36,000 kilometers (22,500 miles) from Earth's surface, may be out by some 4,000 kms (2,500 miles), Giorgina told AFP. <br /><br />In 2029, the asteroid will in fact swing by at around 32,000 kilometers (20,000 miles), making it an even narrower shave. <br /><br />More at the link..<br /> <div class="Discussion_UserSignature"> <p>"1) Give no quarter; 2) Take no prisoners; 3) Sink everything."  Admiral Jackie Fisher</p> </div>

 

[shuttle_rtf]

>These calculations show that the previous estimate of the flyby, of a distance of 36,000 kilometers (22,500 miles) from Earth's surface, may be out by some 4,000 kms (2,500 miles), Giorgina told AFP.<br /><br />In 2029, the asteroid will in fact swing by at around 32,000 kilometers (20,000 miles), making it an even narrower shave. <<br /><br />I'm confused, it's going to get CLOSER?

 

[silylene old]

Hmmm.....this report is either so recent that it has not been run through either NEODYS or JPL's computer simulators, or the reporter got it wrong. I suspect the latter.<br /><br />Both NEODYS or JPL continue to have this object as a Torino 1.<br /><br />JPL's update as of Sept 3 gave Apophis [2004 MN4] a 1/5560 chance of hitting the earth in 2036.<br /><br />Both JPL and NEODYS actually increased their odds of a collision slightly a couple of weeks ago based on the most recent Arecibo measurments. I am sure these are the exact same measurements that your reference refers to also. My guess is that your reference is comparing the odds of a collision today to what had been believed around Christmas-time. <b>Actually, the last three measurements on July 8 and Aug 19/20 each successively increased the collision odds.</b><br /><br />For much more detailed references, read here:<br />JPL: http://neo.jpl.nasa.gov/risk/<br />NEODYS: http://newton.dm.unipi.it/cgi-bin/neodys/neoibo?riskpage:0;main<br /><br />And for a interesting chatty discussion among those people who search and model near-earth asteroids and possible collisions, check out this newsletter: http://www.hohmanntransfer.com/news.htm<br />When you get to the newsletter, click on "CRT" on the top left for their consolidated risk tables, where you can find the sequential impact each individual sighting and measurement had on the odds of collision. <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]

The flyby in 2029 will miss. The question is, will it swing around again and hit us in 2036. A few feet difference as it passes the earth in 2029 has a big impact in where the asteroid will be in 2036.<br /><br />My discussion in the above post was about the Torino 1 danger in 2036...which all depends on <i>exactly</i> where the asteroid passes in 2029.<br /><br />As I understand it, the latest observation which had the asteroid pass closer to us in 2029 slightly increased the risk of collision in 2036 (compared to what we knew in July 2005). <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>

 

[nyarlathotep]

Is there any chance this rock would contain large amounts of platinum? <br /><br />Since it's coming so close, I'm wondering, has anyone considered the possibility of deflecting and aerobraking this sucker into orbit?<br /><br />

 

[spacefire]

I wonder..is there a way to soft-land an asteroid? <div class="Discussion_UserSignature"> <p>http://asteroid-invasion.blogspot.com</p><p>http://www.solvengineer.com/asteroid-invasion.html </p><p> </p> </div>

 

[silylene old]

I doubt Apopsis contains much Pt, as I have not heard that it is a Fe/Ni type. Most likely, it is mostly rock as most asteroids seem to be.<br /><br />There are two opportunities in 2013 and 2021 when it passes about 0.1 a.u. from earth which might be good times for a probe to rendezvous with it and drop a transmitter onto its suface.<br /><br />Conceivably, a small rocket engine (ion rocket engine?) could be landed onto the asteroid in 2013 or 2021 and be used to give a tiny push at the right times to bring Apopsis "home" on 2029. However, it is almost certainly too massive to successfully aerobrake into orbit around Earth. And this would be an extreme risk, since just the slightest miscalculation in rocket braking a decade earlier could plow it right into earth (it would impact eastern Asia or the western Pacific).<br /><br />Apopsis perhaps could be re-directed to impact the moon in 2029. The moon isn't at all far away from intersecting Apopsis' path in 2029. My proposed collision would make a huge visible smack and would be very interesting scientifically to observe. We would learn a tremendous amount about impact collisions.<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>

 

[silylene old]

NEAR already soft landed on Eros. Google it, the pictures are amazing. <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>

 

[spacefire]

no, I meant softland the asteroid On Earth! <div class="Discussion_UserSignature"> <p>http://asteroid-invasion.blogspot.com</p><p>http://www.solvengineer.com/asteroid-invasion.html </p><p> </p> </div>

 

[silylene old]

<i>The key question is whether Apophis' 2029 trajectory will go through a roughly 2,000-foot-wide region called a "keyhole," says astronomer Clark Chapman of Southwest Research Institute in Boulder, Colo. If it does, its course would be deflected to make an impact with Earth in 2036 very likely, he says.</i><br /><br />http://www.indystar.com/apps/pbcs.dll/article?AID=/20050830/LIVING/508300341/1007 <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]

Some more interesting discussion:<br />http://www.spaceref.com/news/viewsr.html?pid=17771<br /><br /><i>Now, the real issue has become whether Apophis will pass by through the "keyhole" in 2029 that would lead to its resonant return, and Earth impact, on April 13, 2036. (G. Valsecchi explained the technical details of keyholes in his ACM talk.) The 1-in-8000 chance of impact is an unusually high probability for a 300+ meter sized object to strike the Earth in the near future. Thus it ranks at "1" on the Torino Scale, and will likely remain at that level, or even rise to "2" before the next opportunity to observe it happens about 7 years from now. (There is the possibility that radar observations will be successful early next year, but they may serve only to raise the probability of impact by narrowing the uncertainty while still including the 2036 keyhole.) <br /><br />While much refinement in Apophis' orbit is expected by 2013, there remains an inherent uncertainty due to the unpredictable behavior of the Yarkovsky Effect -- an acceleration of an asteroid due to the asymmetry of solar radiation absorbed from the Sun and re-radiated on the afternoon hemisphere of a rotating body. That uncertainty will eventually be resolved during Apophis' close pass in 2021, but that might be cutting it close (if Apophis is actually on an impact trajectory) to mount a reliable deflection mission. These scenarios, being evaluated by JPL, will presumably be addressed in NASA's response to Schweickart's letter. But it already seems to Chesley that a transponder mission to Apophis will not be required prior to the expected orbital improvements in 2013. An issue that has come up in the past was the effect of perturbations by other asteroids. While it is clear that such perturbations are important for NEA's that penetrate the main asteroid belt, Chesley now concludes that for Apophis (an Aten class asteroid), this</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>

 

[silylene old]

Here are the danger zones on Earth, if Apophis collides: <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>