Newly discovered asteroids closely approaching earth.

[MeteorWayne]

<p>Thought I'd create a thread for asteroids that pass within&nbsp;two Lunar Distances (LD) of earth.</p><p>First up is 2009 CC2, a 7-17 meter sized rock that passed within 0.5 lunar distance on February 2nd.</p><p>It is not listed on the JPL Sentry page as a future threat to earth (not that a 12 meter asteroid is a real threat anyhow). There are no virtual impactors listed in the next century.</p><p>MW</p><p>(Edit- I have increased the range to two LD to provide a larger sample size-MW)</p> <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>

 

[michaelmozina]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>Thought I'd create a thread for asteroids that pass within one Lunar Distance (LD) of earth.First up is 2009 CC2, a 7-17 meter sized rock that passed within 0.5 lunar distance on February 2nd.It is not listed on the JPL Sentry page as a future threat to earth (not that a 12 meter asteroid is a real threat anyhow). There are no virtual impactors listed in the next century.MW <br /> Posted by MeteorWayne</DIV></p><p>I guess what I find most disconcerting is the fact that several of these close distance meteors have passed by Earth *before* we even detected them. </p> <div class="Discussion_UserSignature"> It seems to be a natural consequence of our points of view to assume that the whole of space is filled with electrons and flying electric ions of all kinds. - Kristian Birkeland </div>

 

[MeteorWayne]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>I guess what I find most disconcerting is the fact that several of these close distance meteors have passed by Earth *before* we even detected them. <br />Posted by michaelmozina</DIV><br /><br />Yes, but that mostly applies to very small ones like this. In fact it was discovered 2 days after closest approach. That is also because it came out of the sunward direction.</p><p>Larger ones would be discovered before they approach the sun, so we would already have an orbit for them.</p><p>BTW, this asteroid would be big enough (assuming the high end of the size range) to deposit meteorites on the ground, and&nbsp;if it were an iron asteroid, the fragments might even leave small craters. It would break up between 30km (rock) and 7km (iron) above the surface, manly due to it's high speed when it hits the atmosphere (22.7 km/sec)</p><p>This is a rather interesting asteroid; it's in a highly eccentric orbit, with perihelion inside of Venus' orbit (in fact it had a close approach to Venus in November) and aphelion on the outer edge of the main asteroid belt. (0.61 AU / 3.18 AU)</p><p>MW</p> <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>

 

[MeteorWayne]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>I guess what I find most disconcerting is the fact that several of these close distance meteors have passed by Earth *before* we even detected them. <br />Posted by michaelmozina</DIV><br /><br />As an example, 2009 BK58 was discovered 3 days before closest approach, 18-41 m in diamteter. However, if it were an iron asteroid at the high range of the size range, it would be very comparable to Meteor Crater in Arizona in effect. That wouldn't be good if you were too close. For example (remember, this is worst case, Iron, like the Canton Diablo object), if you you were only 2 km away...</p><p>Multistory wall-bearing buildings will collapse.<br /><br />Wood frame buildings will almost completely collapse.<br /><br />Multistory steel-framed office-type buildings will suffer extreme frame distortion, incipient collapse.<br /><br />Highway truss bridges will collapse.<br /><br />Highway girder bridges will collapse.<br /><br />Glass windows will shatter.<br /><br />Cars and trucks will be overturned and displaced, requiring major repairs.<br /><br />Up to 90 percent of trees blown down; remainder stripped of branches and leaves.</p><p>If it makes everyone feel better, this is also not an impact risk for at least the next century or more.</p> <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>

 

[michaelmozina]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>Yes, but that mostly applies to very small ones like this. In fact it was discovered 2 days after closest approach. That is also because it came out of the sunward direction.Larger ones would be discovered before they approach the sun, so we would already have an orbit for them.BTW, this asteroid would be big enough (assuming the high end of the size range) to deposit meteorites on the ground, and&nbsp;if it were an iron asteroid, the fragments might even leave small craters. It would break up between 30km (rock) and 7km (iron) above the surface, manly due to it's high speed when it hits the atmosphere (22.7 km/sec)This is a rather interesting asteroid; it's in a highly eccentric orbit, with perihelion inside of Venus' orbit (in fact it had a close approach to Venus in November) and aphelion on the outer edge of the main asteroid belt. (0.61 AU / 3.18 AU)MW <br /> Posted by MeteorWayne</DIV></p><p>There's just something rather uncomfortable about knowing that it could have created a small crater in my backyard (yes, I know the odds are astronomically low) *before* we even knew it was there. &nbsp; I hear you on the size issue, and I'm sure this is the single largest factor in them remaining "hidden" for so long.&nbsp;&nbsp; It just always makes me wince a little bit when we discover these things only *after* they have passed by Earth. </p> <div class="Discussion_UserSignature"> It seems to be a natural consequence of our points of view to assume that the whole of space is filled with electrons and flying electric ions of all kinds. - Kristian Birkeland </div>

 

[michaelmozina]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>As an example, 2009 BK58 was discovered 3 days before closest approach, 18-41 m in diamteter. However, if it were an iron asteroid at the high range of the size range, it would be very comparable to Meteor Crater in Arizona in effect. That wouldn't be good if you were too close. For example (remember, this is worst case, Iron, like the Canton Diablo object), if you you were only 2 km away...Multistory wall-bearing buildings will collapse.Wood frame buildings will almost completely collapse.Multistory steel-framed office-type buildings will suffer extreme frame distortion, incipient collapse.Highway truss bridges will collapse.Highway girder bridges will collapse.Glass windows will shatter.Cars and trucks will be overturned and displaced, requiring major repairs.Up to 90 percent of trees blown down; remainder stripped of branches and leaves.If it makes everyone feel better, this is also not an impact risk for at least the next century or more. <br /> Posted by MeteorWayne</DIV></p><p>Having personally stood at the bottom of that particular crater, I can assure you that you aren't making me feel any safer. </p><p>&nbsp;</p> <div class="Discussion_UserSignature"> It seems to be a natural consequence of our points of view to assume that the whole of space is filled with electrons and flying electric ions of all kinds. - Kristian Birkeland </div>

 

[MeteorWayne]

Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>Having personally stood at the bottom of that particular crater, I can assure you that you aren't making me feel any safer. &nbsp; <br />Posted by michaelmozina</DIV><br /><br />Kewl! You got to go inside? I only got to look from the rim. It still was a shock and awe experience. <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>

 

[michaelmozina]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>Kewl! You got to go inside? I only got to look from the rim. It still was a shock and awe experience. <br /> Posted by MeteorWayne</DIV></p><p>I think I was about 12 at the time.&nbsp; As I recall it took over an hour to hike to the bottom and back up. &nbsp; </p> <div class="Discussion_UserSignature"> It seems to be a natural consequence of our points of view to assume that the whole of space is filled with electrons and flying electric ions of all kinds. - Kristian Birkeland </div>

 

[MeteorWayne]

Two new ones to add to the list.
Asteroid 2009 DT 43, between 12 and 27 meters in size, was discovered the day after closest aaproach at 1.0 lunar distance.

Asteroid 2009 DD45, between 21 and 47 meters in diameter, will have a VERY close approach tomorrow of only 0.2 lunar distance. This will be about 71,807 km (44,618 miles), about twice the distance of a geostationary orbit. It was discovered on Feb 27th, about 2 days before closest approach. That was a close one!

Neither is a threat for future earth impact (at least through the next 100 years)

 

[MeteorWayne]

Just to keep the list in one place, 2009 DD45 (21-47 m) passed within 0.2 LD (Lunar Distance) of earth on March 2 (discovered 2/27)
That.s ~ 71,807 km, or 35,786 miles. It was never an impact threat

2009 EJ1 (6-13m) passed even close On Feb 27, ~59,800 km, or 37,200 miles. It was not discovered until March 3rd.
It has a very low possibility of impact beginning in 2036.

2009 EW (14-31m) will pass 0.9 LD from earth of March 6th, discovered on March 2nd. It has a low risk of impact beginning in 2063.

2009 EH1 (7-16m) will pass within 1.6 LD on March 6th, it was discovered March 3rd. it has a very low risk of impact beginning in 2048
MW

 

[MeteorWayne]

On a related note, 2004 XY130 (# 3329 discovered Dec 1-15 2004) was one of the highest risk asteroids for an earth impact (in fact it was scheduled for April 18th this year!) has been removed from the list of potential impactors. It was recovered last year and preliminaryily designated 2008 SM 127 (another busy half month). Once it's orbit was refined, it was realized that it was 2004 XY 130, and the 4 year observational arc showed there is no longer any impact risk with earth (at least for the next 100 years).
It was removed from the impact risk list on October 29th. And it's a good thing, since it is quite large, about 500 meters.
Here's it's revised SSB database page:

http://ssd.jpl.nasa.gov/sbdb.cgi?sstr=2 ... ;cad=0#orb

The next asteroid with a non-zero impact risk is 2004 FU 162 (# 4095 or so for that half month!! ) with a possibilty of hitting the atmosphere on March 31. It's orbit is VERY poorly known with only 4 observations over a 45 minute period. It most likely will be on the other side of the solar system at that time. It's not a threat though, only about 6 meters in size.

 

[MeteorWayne]

Just to keep the list in one place, 2009 DD45 (21-47 m) passed within 0.2 LD (Lunar Distance) of earth on March 2 (discovered 2/27)
That.s ~ 71,807 km, or 35,786 miles. It was never an impact threat

2009 EJ1 (6-13m) passed even close On Feb 27, ~59,800 km, or 37,200 miles. It was not discovered until March 3rd.
It has a very low possibility of impact beginning in 2036.

3/15 update: there are 9 very low impact possibilities from 2036-2086

2009 EW (14-31m) will pass 0.9 LD from earth of March 6th, discovered on March 2nd. It has a low risk of impact beginning in 2063.

3/15 update, there is now only 1 very very low impact risk in 2075

2009 EH1 (7-16m) will pass within 1.6 LD on March 6th, it was discovered March 3rd. it has a very low risk of impact beginning in 2048

3/15 update, there are now 2 very very very low risk impacts, one in 2060, and one in 2094

MW

 

[MeteorWayne]

Asteroid 2009 DO111 will pass within 1.2 lunar distance on March 20. It's between 76 and 170 meters in diameter, and currently has 25 low probability possible impacts between 2068 and 2108. It's got a fairly long observational arc (21 days, from Feb 22 through now) so it may take a little while to fall off the risk chart. It's in a low inclination orbit from just outside that of Venus, to just inside that of Mars.

Edit: 3/17 update, the number of possible impacts is down to 17 between the same years mentioned above

Edit 3/20 Update, number of impacts down to 6, the earliest in 2091

 

[MeteorWayne]

Looks like a data dump just happened. 2 close approaches, and a few more on the risk page, all in the 2009 F series (March 16-31)

Both the close approaches are small asteroids.

First, a VERY close approach from 13-29 meter 2009 FH in a few hours; 0.2 LD, about 85,000 km. No future impact risk.

On the 20th, 2009 FK (which has a very very very low risk of future impact) 6-14 meters in size passes by at the moon's distance (1.0 LD)

 

[eosophobiac]

MW,
What about the one that was very prominent in the news not too long ago - Apophis, I think? Are there any updates to that one? Is it still predicted to be a close call? (I think the last I heard/read, it would be close but no impact.)

And thanks for this thread - it's very interesting!

 

[MeteorWayne]

Yeah, I know Apophis is a real news maker, but it is not the highest risk object. It is however the largest, and soonest object. We won't know more abouit it for another 2 years or so, until it comes close enough for radar observations. It is likely that such observations will refine the orbit somewhat, but probabably not enough to totally eliminate an impact risk in 2036.

The impact potential for Apophis is in 2036.

2007 VK 184 actually has 10 times the impact risk, but doesn't begin until 2048. It is the only object with a "1" rating on the Torino scale, Apophis is a zero.

There are two other objects with higher impact probabilities; 1999 RQ36 and 2001 WN5, but they are not a threat until long after we are worm food, 2133-2199.

Wayne

 

[porkchopsnapplesauce]

What sort of Orbits are these asteroids on? Are they in a similar orbit as the earth, or do they move in towards the sun and fling back out towards the gas giants? I am guessing they are all different, but am curious if their orbits give us some info about their history

 

[MeteorWayne]

There's a wide variety. I always look them up when I post about them and comment on the interesting ones. Some come from the asteroid belt and the perihelion of their orbit still resides there. Others are in much more circular orbits. As with most stuff in the solar system, most of them travel around the sun the same direction that we do, in low inclination orbits. That's a good thing, should there ever be an impact, since it keeps the collision speeds down which greatly reduces the enrgy of the impact.
Bottom line, there's many different orbits, but most are similar to 98% of the objects in the solar system. There was one (I think in this thread) that went around the sun in the opposite direction, which suggests a possible cometary origin.

 

[eosophobiac]

snippet:

The impact potential for Apophis is in 2036.

Wayne

2036???? I guess it's been changed - or I fell asleep!!! I thought it had been estimated for potential impact in 2039, which isn't really a huge difference, but .......

Not like I'm a 'Chicken Little' or anything, :lol: but I'll definitely keep checking back!

 

[MeteorWayne]

2036 is correct. There is a close approach in 2029, close enough to earth that it our gravity will change it's orbit. If it passes through a very small (few hundred meter sized) window or as it's called a "keyhole" in 2029, then it will make an impact in 2036 possible.

 

[michaelmozina]

I guess what I find most disconcerting about these close approaches is that 18 of the 20 asteroids have names suggesting they were only found *this year*.

 

[MeteorWayne]

But again, look at the stats. Most of those are VERY small, too small to be a threat to earth. We are discovering more and smaller asteroids at an astounding rate.

 

[michaelmozina]

But again, look at the stats. Most of those are VERY small, too small to be a threat to earth. We are discovering more and smaller asteroids at an astounding rate.

I guess if you look at it that way.....

 

[asterannie]

I am a novice here, so please be kind! I have second hand knowlege (from a friend of someone who is very high up in the chain of command at the VLA (Very Large Array), that 2009 FD, which just zipped by at 1.6 LD (.00416795 AU) will return in early May (10th ish) at .1 LD which would indicate a VERY near miss. She mentioned that they have an agreement with the government to not annouce these very close flybys until after they occurr because it would incite panic.

Can anyone comment on this? I looked on Spaceweather and the JPL Small Body Database and can't find something that looks that close...

 

[silylene]

I am a novice here, so please be kind! I have second hand knowlege (from a friend of someone who is very high up in the chain of command at the VLA (Very Large Array), that 2009 FD, which just zipped by at 1.6 LD (.00416795 AU) will return in early May (10th ish) at .1 LD which would indicate a VERY near miss. She mentioned that they have an agreement with the government to not annouce these very close flybys until after they occurr because it would incite panic.

Can anyone comment on this? I looked on Spaceweather and the JPL Small Body Database and can't find something that looks that close...

I checked and I don't see 2009FD making another close approach until the year 2069, when it will come close to both the earth and the moon on March 28/29: http://ssd.jpl.nasa.gov/sbdb.cgi?sstr=2009 FD;orb=1;cov=0;log=0;cad=1#cad

On 8 May 2009, 2009FD is actually somewhat close to Venus.