Newly discovered asteroids closely approaching earth.

[silylene]

On 2010 RF12, JPL now listing it as PS = -3.67 cum (2.2% chance of collision!), while NEODyS has removed it from the danger list. It is rare the two simulations disagree to this degree. The object is very small, this may be the reason why (NeoDys figures it would burn up anyways with no damage?).

Nope, here's why, from NEODyS:

"In this page we list all the asteroids for which possible impact solutions, compatible with the existing observations and in a time span from nowadays till 2080, are known, although we are now extending our monitoring to 2090"

All the potential JPL Sentry Impactors are from 2095 to 2110, outside of the NEODyS calculations.

MW

Ah-ha. So it may get re-listed in 10-15 years.

 

[MeteorWayne]

Or sooner if NEODyS extends their temporal range.

Or far more likely with new observations (tonight before close approach) the risk will drop to zero and it will vanish from the risk list.

After this close approach though, it heads between us and the sun, so we need the observations within the next 24 hours or so, and based on the current orbit won't be as close as it was at detection again until the 2095 potential impact.

Since it is moving so fast across the sky tonight, even a few observations will tightly constrain the possible orbit.

It will be moving ~ 30 degrees across the sky in the last hour before CA, or about 2 degrees (4X the diamater of the moon) a minute, or a moon width every 15 seconds! At brighter than mag +15 there should be a wealth of new data.

Otherwise, after 60 days it will drop into the "Not Recently Observed" list in 16th place for 85 years or so

MW

 

[MeteorWayne]

Can't wait to see what the scientifically ignorant Mainstream Media does with this opportunity :lol:
E-mail from NASA...

"NASA Scientists Talk About Asteroids Passing Near Earth Wednesday WASHINGTON -- Two asteroids will pass within the moon's distance from Earth on Wednesday, Sept. 8. NASA scientists will be available for satellite interviews Tuesday, Sept. 7, and Wednesday morning to discuss these near- Earth objects.

The Catalina Sky Survey near Tucson, Ariz., discovered both objects on Sunday, Sept. 5. The Minor Planet Center in Cambridge, Mass., reviewed the observations and determined the preliminary orbits. The center's personnel concluded both objects would pass within the distance of the moon to Earth, approximately 240,000 miles. The asteroids should be visible with moderate-sized amateur telescopes.

Neither asteroid will hit Earth. Asteroid 2010 RX30 is estimated to be approximately 32 to 65 feet in size and will pass within approximately 154,000 miles of Earth at 5:51 a.m. EDT Wednesday. The second object, 2010 RF12, estimated to be 20 to 46 feet in size, will pass within approximately 49,000 miles at 5:12 p.m. EDT.

NASA scientists are available for interviews about the asteroids via NASA Television, Skype or telephone. TV producers can call to schedule afternoon interviews and morning interviews. For NASA TV downlink, schedule and streaming video information, visit:

http://www.nasa.gov/ntv "

 

[MeteorWayne]

SDC finally caught up to their own forum, 43 hours later

SDC Story

"2 Asteroids to Zoom Between Earth and the Moon's Orbit
By Denise Chow
SPACE.com Staff Writer
posted: 08 September 2010
01:42 am ET


Two asteroids will zip close by the Earth Wednesday and may be visible in telescopes as they zip between our planet and the orbit of the moon.

The asteroids, which will not be visible to the naked eye, were discovered Sunday by astronomers with the Catalina Sky Survey near Tucson, Ariz. They are traveling along different orbits that, by coincidence, pass near Earth about 11 hours apart."

Yes, they would be visible from here now in my scope if it wasn't overcast

To get accurate positions, you must use the JPL Small Body Database pages for them I linked to above, then select Ephemerides, enter your position on earth, select a time interval no longer than 15 minutes (since 2010 RF12 will be moving the diameter of the full moon every 15 seconds at close approach) then create it.

MW

 

[MeteorWayne]

Updates from new observations.

2010 RX30, now 77 obs over 2.5398 days.
Close approach this morning was at 247,723 +/- 210 km at 09:51 UT (153,928 +/- 117 miles)
The potential impactors have been reduced to 3 from 2063-2066, with a cumulative PS of -6.29

2010 RF12, now 119 obs over 2.7075 days.
Close approach is still predicted at 21:12 UT tonight at 79,390 +/- 35 km ( 49,331 +/- 22 miles)
Very slight reduction in risk to PS -3.95; still 54 impacts between 2095 and 2110, so little change there as well.

 

[MeteorWayne]

Asteroid Near Misses Common

"Two asteroids swooping past Earth Wednesday may have caught the attention of the public, but events like these are not actually rare, NASA scientists say.

"This is the first time we've seen [two] combined within a 24-hour period, but that's probably because we don't know everything that is out there," said Lindley Johnson, program executive of the Near-Earth Object program at NASA headquarters in Washington. ....

In fact, with a rough estimate of 50 million unknown asteroids, a 33-foot-wide (10-meter) near-Earth object could pass harmlessly between Earth and the orbit of the moon every day, Johnson added. Such an asteroid might hit Earth's atmosphere once every 10 years, but because of its small size, it would pose no substantial threat to the people or property below. "

 

[EarthlingX]

Two videos about those two asteroids :

http://www.youtube.com/user/Kowch737 :

Asteroid 2010 RX30
[youtube]http://www.youtube.com/watch?v=sGfGBGzuD84[/youtube]

Asteroid 2010 RF12
[youtube]http://www.youtube.com/watch?v=yTJoY5QTVEM[/youtube]


http://www.planetary.org : Early warning for close approaches of two house-sized asteroids

Sep. 8, 2010 | 11:31 PDT | 18:31 UTC

By Emily Lakdawalla

Most of you have probably heard by now of two small asteroids, both in the neighborhood of 10 meters in diameter, recently discovered on trajectories that pass unusually close to Earth. They were discovered on September 5 by the Catalina Sky Survey, and have since been observed by numerous amateur and professional astronomers. Neither poses any risk to Earth; even if they were on collision courses, which they are not, they would be too small to do much more than spatter a few rocks onto the ground. It'd be a bad day for you if you were underneath that, but these rocks wouldn't do any collateral damage outside their physical impact zone.

I was thinking today about how these early warnings of close approaches are going to be coming more and more frequently as surveys improve. Every time one of these close-approaching bodies is discovered and flagged as a potential hazard, dozens (hundreds?) of willing amateur astronomers go to their scopes and photograph the asteroids against the background of stars to help refine their paths. Every time, greater precision has retired the risk from the asteroid to be pretty much negligible. That makes me wonder how things will unfold the first time we do discover an impactor -- or, I should say, the second, because 2008 TC3 was the first such body observed from space down to the ground. But TC3 was roughly an order of magnitude smaller than RX30 and RF12; the newly discovered things would make much, much bigger sky shows. When will some astronomer, professional or amateur, make that first chilling discovery that something big enough actually to do some damage is going to impact for sure? Tomorrow? Not for a hundred years? How will that unfold?

Here's just one recent amateur view of 2010 RF12, by Ernesto Guido and Giovanni Sostero of Remanzacco Observatory. These things move so very fast that they show up as elongated blips for most observers.

 

[MeteorWayne]

OK, new observations on both asteroids. Refinement in the close approach distances, and big changes in risk,

First the smaller, closer, and riskier asteroid:

2010 RF 12. Now 299 observations over 2.071 days.
Close approach was at 79,382 +/- 17 km, or 49,326 +/- 11 miles.
Risk has increased; it's now in 11th place in risk of those listed in JPL's Sentry with as PS of -3.35 for 40 potential impacts between 2095 and 2110. Almost all the risk is concentrated in the first, at almost exactly midnight UTC Sept 6, 2095 with a 5% (1 in 20) chance of impact.
As an interesting side note silylene, I see NEODyS has added this asteroid back, with 5 impacts between 2095 and 2100; they must have manually forced the calculations beyond the automatic cutoff. PS is -3.38.

2010 RX30. Only one new observation added, but big change in lowering the risk.
Close approach was at 247,764 +/- 168 km, or 153,953 +/- 104 miles.
Risk has plummeted, now PS -8.20 for only two impacts 10 years apart, on Sept 8 2063 and 2073. Almost all the risk is associated with the far more likely first one with a 1 in 11 million chance of impact.
NEODyS has dropped this one from the risk list, probably because of a slightly different orbit precluding
impact.
MW

PS, there are 245 objects on the NEODyS risk list, 299 on JPL's Sentry.

 

[silylene]

OK, new observations on both asteroids. Refinement in the close approach distances, and big changes in risk,

First the smaller, closer, and riskier asteroid:

2010 RF 12. ....at almost exactly midnight UTC Sept 6, 2095 with a 5% (1 in 20) chance of impact.....
As an interesting side note silylene, I see NEODyS has added this asteroid back, with 5 impacts between 2095 and 2100; they must have manually forced the calculations beyond the automatic cutoff. PS is -3.38.
MW

Good thing this is a very small asteroid!

 

[MeteorWayne]

A few new observations included today

2010 RF12, now 311 observations in 3.0701 days. Close approach was 79,383 +/- 15 km, or 49,326 +/- 9 miles.
Risk updates: Palermo Scale: JPL -3.29, NEODyS -3.31 (the difference is caused by NEODyS rejecting 3 of the 313 obs as outliers, JPL Sentry, only 2). Sentry 35 impacts 2095-2110 (10 2095-2100), NEODys 9 from 2095-2100. Almost all of the risk is for the first listed virtual impactor on 2095-09-05.99 (Midnight UTC Sept 5/6, 2095)
If the PS risk goes below -3.00, I will start a dedicated thread, and copy all the posts on this object to it.

2010 RX30, now 87 obs over 2.9582 days. CA was 247,653 +/- 97 km, or 153,885 +/- 61 miles. JPL Sentry has PS -7.87, now 3 potential impactors from 2063-2103.

MW

 

[MeteorWayne]

A few new obs on 2010 RF12, some minor changes...

316 obs over 3.1110 days. CA was 79,382.4 km +/-15 km, or 49,325 +/- 9 miles.

PS went down, back to -3.31 (Sentry) with now 33 potential impacts between 2095 and 2110. Still, all front end loaded to the 2095 VI.

No new obs on 2010 RX30.

 

[MeteorWayne]

Few more obs of 2010 RX30, now 91 obs over 2.9582 days.
New CA distance 247,644 +/- 96 km, or 153,879 +/- 60 miles.
New PS -7.46 for 2063 impact, cumulative PS -7.43 for 3 VI's between 2063 and 2103.

Also two new small asteroids with CA distance of 2.2 LD, both discovered after the close approach.

2010 RM82; CA 9/10, discovered 9/12, 19-43 meters diameter

2010 RS80; CA 9/9, discovered 9/11, 14-31 meters diameter.

 

[MeteorWayne]

Well, we can pretty much put both of the close approach asteroids in the rear view mirror. Both 2010 RF12, and 201RX30 are now too close to the sun to be observed for at least the next 60 days, and after that will be too far away to be spotted given their tiny dimensions (and therefore faintness). So in the beginning of November, barring any prediscovery images (unlikely) or any obs from two weeks ago that haven't been reported (possible) they will fall off the Sentry "Recently Observed Objects" to the "Objects Not Recently Observed" where they will reside for a long time.

2010 RF12 will move into the 11th riskiest asteroid (ranked by Palermo Scale), and 2010 RX 30 will be no higher than 240th place

MW

 

[csmyth3025]

Just out of curiosity, does anyone know how big of a bang a ~10 meter meterorite (let's say nickle-iron, for the sake of argument) would make? These sizes are what they are estimated to be in space. How much of their mass is ablated by the atmosphere? I know these questions depend on their composition, velocity and angle of entry. I'm wondering if they would make a crater at all - just a ball park estimate.

Chris

 

[EarthlingX]

Perhaps this can be of help, from the Relativity Calculator thread :

impact.ese.ic.ac.uk : Earth Impact Effects Program


Results for 10m, 15km/s, iron, 1km away, 45º angle, hitting sedimentary rock

Energy:
Energy before atmospheric entry: 4.71 x 1014 Joules = 112.57 KiloTons TNT
The average interval between impacts of this size somewhere on Earth is 24.7 years

Atmospheric Entry:
The projectile begins to breakup at an altitude of 11400 meters = 37500 ft
The projectile bursts into a cloud of fragments at an altitude of 6090 meters = 20000 ft
The residual velocity of the projectile fragments after the burst is 5.9 km/s = 3.66 miles/s
The energy of the airburst is 3.98 x 1014 Joules = 0.95 x 10-1 MegaTons.
Large fragments strike the surface and may create a crater strewn field. A more careful treatment of atmospheric entry is required to accurately estimate the size-frequency distribution of meteoroid fragments and predict the number and size of craters formed.

 

[csmyth3025]

Thanks Earthlingx for the info and the link.

I noticed that a 40 meter nickle-iron meteorite traveling at 20km/sec would take out New York, Newark and a good part of Yonkers. Given the rather chaotic evacuation of New Orleans, I wonder how much lead time we would need to project the site of impact for such an object and implement an evacuation.

Chris

 

[MeteorWayne]

Consider the lead time could be zero...

"Also two new small asteroids with CA distance of 2.2 LD, both discovered after the close approach.

2010 RM82; CA 9/10, discovered 9/12, 19-43 meters diameter

2010 RS80; CA 9/9, discovered 9/11, 14-31 meters diameter.

 

[csmyth3025]

Considering the (remote) possibility that something like this could slip by unnoticed, I hope the military types have the good sense to make sure it's not a nuclear strike before they start pushing any buttons. I suppose they could tell pretty quickly by the radiation signature (or lack thereof).

Chris

 

[marsbug]

I don't suppose anyone has heard of any spectrometry observations being done of these two asteroids? It would be nice to have a classification to go with the designations.

 

[MeteorWayne]

Not yet.

 

[MeteorWayne]

Newly discovered tiny asteroid (9-19 meter dia) 2010 SK13 passed within 0.7 Lunar Distance about an hour ago. It was discovered on the 28th, and is on the risk page with a very low (cumulative PS -6.10) chance of 3 possible impacts from 2080-2084.

 

[centsworth_II]

Hey, you guys are asleep at the switch! :lol:

"...object RT9B991... may come very close to Earth in the next days."

I had to read about it HERE!

 

[EarthlingX]

Re: Newly Discovered PHA's

http://www.universetoday.com : Breaking News: Small NEO Could Pass Within 60,000 km of Earth on Tuesday

Oct 10th, 2010

by Nancy Atkinson

A small asteroid will likely pass very close to Earth this week Tuesday. Astronomers are still tracking the object, now designated as 2010 TD54, and various estimates say it could possibly come within anywhere from 52,000 km (33,000 miles) to 64,000 km (40,000 miles) on October 12, with closest approach at approximately 11:14 UT. Information on the IAU Minor Planet Center website lists the object as coming with 0.0003 AU. The size of the object has not been determined, but estimates say it is likely smaller than 10 meters. We’ll provide an update as soon as more information is available.

UPDATE: Don Yeomans, Manager of NASA’s Near-Earth Object Program Office replied to an inquiry about the object and said the newly discovered NEO 2010 TD54 is approximately 5-10 meters in size, and is now predicted to pass about 46,000 km from Earth’s surface at about 07:25 EDT (11:25 UT) on Tuesday, Oct 12, 2010. It was discovered by Catalina Sky Survey on Saturday morning.

“Only 1 in a million chance of an impact,” Yeomans said, “and even if it does impact, it is not large enough to make it through the Earth’s atmosphere to cause ground damage.”

Sources: IAU Minor Planet Center, Unmanned Spaceflight, Yahoo News Groups

 

[MeteorWayne]

Since it is not yet on the Sentry risk page, I moved the last post the Newly Discovered Close Approach thread.

Information on 2010 TD54; based on 30 obs over 2 day arc.

Close Approach Oct 12, 10:51 UTC. Nominal distance 51,856 km (32,222 mi). Minimum distance 51,542 km (32,026 miles)
Estimated size 4.6-10 meters diameter. (H=28.8)

Discovered Oct 10 09:20 UT by the Mt Lemmon Survey (Part of the 3 station Catalina Survey), which gets most of the tiny ones...

It seems the orbit will be changed in the future with close approaches to Venus (JPL Sentry, Nov 9 this year), and from NEODyS, 4 Vesta in 2029 and Mars in 2030, so it is not an impact risk for earth despite this very close approach.

 

[frodo1008]

What is very scary to me at least is that even a very small asteroid (say 40 meters in diameter) has the potential of destroying a major city anywhere on the Earth. I wonder if all the cost conscious people that keep space spending to a minimum, realize that such an event could do literally dozens of $trillions of dollar worth of damage. To say nothing of literally millions killed and injured!

The costs of just one such an instance would be magnitudes larger that all of the costs of all of the space programs of mankind since the beginning of mankind itself!

Yet we just roll along doing nothing. Are we really no smarter than the dinosaurs were???

Heck, their would be plenty of funding for our very real "WAR" with a very violent and uncaring universe if we would just stop fighting useless wars among ourselves!!

When we finally lose that war (and at the rate we are going, we will lose sooner or later) , it will be a really, really big loss! :x :x :x