Interesting "asteroid" 2010 AL30 close approach. Poss Rocket

[MeteorWayne]

Newly discovered (today) tiny asteroid (11-25 meters) 2009 AL 30 will pass only 0.3 Lunar Distance from earth on Wednesday. It's interesting in that it has an almost perfect 1 year period (366 days so far) although the orbit ranges from 0.7 to 1.3 AU. It's also a low inclination orbit.

Note the size estimate assumes it's a real live asteroid, not a piece of a launch vehicle. If that's the case, it might be brighter than an asteroid, hence smaller than the estimated size

 

[MeteorWayne]

Re: Newly discovered asteroids closely approaching earth.

From spaceweather.com: http://www.spaceweather.com/

CURIOUS FLYBY: A curious object is about to fly past Earth only 130,000 km (0.3 lunar distances) away. Catalogued as a 10m-class asteroid, 2010 AL30 has an orbital period of almost exactly 1 year. This raises the possibility that it might not be a natural object, but rather a piece of some spacecraft from our own planet. At closest approach on Jan. 13th, 2010 AL30 will streak through Orion, Taurus, and Pisces glowing like a 14th magnitude star. Experienced amateur astronomers are encouraged to monitor the flyby: ephemeris.

 

[MeteorWayne]

Re: Newly discovered asteroids closely approaching earth.

Looking at the SBDB page, it kind of looks like, if it is a launcher, it might be for a Venus mission either in 1985,2003, or 2006.

Once the orbit diagram loads, grab the handle on the scroll bar to the right and move it all the way to the bottom (so you are looking at the solar system straight down from above). Then grab the zoom handle to zoom in a little.

You can see it comes very close to intersecting Venus' orbit.

Down at the bottom, I have included the close approach tables, where I got the dates listed above.

So a mission to Venus might leave part of it's launcher in such an orbit. Mars is another possibility (if a second stage added more velocity)

Just spitballin' here....

 

[MeteorWayne]

If I were to take a WAG, I'd suspect something associated with ESA's Venus Express, but that's a VWAG

 

[christcore]

What time can I expect to see this?! I am in the Mountain Time Zone.
Thanks

 

[MeteorWayne]

The period of rapid motion will be after sunrise for the US, but for anywhere, the best time will be closest to dawn. It's quite faint, though...mag +14 or so, so large binocs or a scope will be required.

 

[MeteorWayne]

Observations are coming it at a rapid pace. The JPL sbdb page on this object
http://ssd.jpl.nasa.gov/sbdb.cgi?sstr=2 ... ;cad=1#cad

has already been updated 3 times today with new observations...I've never seen that before except for 2008 TC3.

If you intend to look for it tonight, go to that page, click on the Ephemeris link, BE SURE TO ENTER YOUR CORRECT LAT/LONG, ensure that 399 (earth) is selected as the parent object and 2010 AL30 is the target, and pick a time interval of no more than 30 minutes. For those on the west coast, I might even use 15 minutes. Use a time interval from 2010-01-13 to 2010-01-14 for the US mainland and Hawaii, 2010-01-12 to 2010-01-14 for everyine else. And get out your star charts. Do it right before it gets dark, so the latest data is included.

It is currently in Gemini, but by late morning it will be in Aquarius!!!!

 

[MeteorWayne]

Another huge data dump. When I looked this morning, there were 25 observations, an hour ago 46, now there are 115.
The period has been refined to 366.0950370759343 +/- 0.010041 days,
semimajor axis to 1.001529185877961 +/- 1.8313e-05 AU

MW

 

[MeteorWayne]

Now 152 observations.

Fascinating...for the average close approach or even potentially hazardous asteroid it takes weeks or months or never to get this many observations.

It's still a 2 day arc, though

 

[MeteorWayne]

I should point out that after about 1500 UTC on the 13th, it will be on the sun side from earth, so will no longer be visible.

 

[MeteorWayne]

Now 152 observations.

Fascinating...for the average close approach or even potentially hazardous asteroid it takes weeks or months or never to get this many observations.

It's still a 2 day arc, though

To back that up, the only Torino Scale 1 object on the risk list, 2007 VK184 has 101 observations over a 60 day arc

2001 WN5 116 obs over 4710 days (PS -2.13)

1994 WR12 24 obs over 35 days (PS -2.99)

 

[MeteorWayne]

Wow, 5 updates in about 12 hours...unprecedented. Now 168 observations.

 

[a_lost_packet_]

2010 AL30

News Story:

2010 AL30: Asteroid or Space Junk? (Updated)

UPDATE (3:30pm ET): According to NASA's Jet Propulsion Laboratory's Small Body Database, 2010 AL30 has now been classified as an "Apollo" class near-Earth asteroid (NEA) rather than anything manmade. Apollo class asteroids cross the path of the Earth and are confined to an orbit around the sun similar to that of our planet. This classification is named after an asteroid called 1862 Apollo that was discovered in 1932. [Thanks to Charles Bell for notifying me about this development.]


A near-Earth object that could be manmade has just been discovered hurtling toward us. On Wednesday (Jan. 13), an object called 2010 AL30 will fly by Earth at a distance of just 130,000 km (80,000 miles). That's only one-third of the way from here to the moon, ie: very close.

It will miss us, and if it did hit us, it wouldn't do any damage anyway, but I managed to pick up on some chatter between planetary scientists and found out that the "asteroid," or whatever it is, gives us a new standard: a 10-meter-wide asteroid can be detected two days before it potentially hits Earth. A pretty useful warning if you ask me. ...

Question(s):

I'm curious as to how there could be any question regarding this object's origins. I understand the reasoning that because it seems to share a similar orbit, it could possibly be manmade. But, that begs the question, if it had a chance to be manmade, how could it have gotten there in the first place and achieved its own orbit about the Sun?

It was my understanding a certain amount of energy is necessary to move object A from Earth into Earth orbit x. More energy is needed to escape Earth's gravity and establish a new, independent, orbit around the Sun. How is "space junk" able to transition from Earth orbit into a Solar-centric orbit on its own?

Could it somehow be perturbed by other forces, such as the Moon? Other bits of junk? What would cause a bit of space junk to undetectably become free of Earth's orbit which could then give rise to such claims that this could be manmade?

 

[csmyth3025]

2010 AL30

"...The space rock won't hit the Earth, but it will make its closest approach at 7:45 a.m. EST (1245 GMT) [Wednesday] when it comes within 80,000 miles (130,000 km) of our planet. That's nearly one-third the distance between the Earth the moon.

Astronomers announced the discovery of the asteroid, which they named 2010 AL30, on Monday. It is relatively small, about 36 feet (11 meters) wide, NASA researchers said..."

The above quote was taken from Space.com's artilcle about this object posted on their site Tuesday at 5:15 PM.

This article brings to mind several questions which I'm sure have been asked about other similar occurances.

First, this object seems to be about the size of a small house. If, for the sake of argument, it turns out to be a nickle-iron asteroid, what sort of crater (on land) might it produce? I ask this with the thought in mind that Meteor Crater (aka Barringer Crater) in Arizona is believed to have been produced by a nickle-iron asteroid about 50 meters wide. Wikipedia describes Meteor Crater as being about 1200 meters (~4,000 feet) in diameter. If it were to land in a populated area I suspect that it might take out a city block or a sizable piece of a suburban area.

Conversely, if it landed in the ocean might it produce tsunamis? I know these questions are hard to answer because they require a knowledge of the velocity, angle of approach, composition, and place of impact of this asteroid.

My second main question concerns the timeline described in the Space.com article - which is that the discovery of this object was announced on Monday and the closest approach is expected to be Wednesday. Is this typical for objects this size?

I ask these questions not because I believe doomsday is coming anytime soon. I am curious, however, about how large of an object might be able to "sneak up" on us and give us just a couple of days warning.

Chris

 

[MeteorWayne]

Post merged into the existing discussion.

Yes, a day or two lead time is typical for objects this small.

 

[MeteorWayne]

Re: 2010 AL30

Question(s):

I'm curious as to how there could be any question regarding this object's origins. I understand the reasoning that because it seems to share a similar orbit, it could possibly be manmade. But, that begs the question, if it had a chance to be manmade, how could it have gotten there in the first place and achieved its own orbit about the Sun?

There are a number of launchers for lunar and planetary missions that now orbit the sun. Once they exceed 11.2 km/sec relative to the earth (while launching the spacecraft) , they are no longer directly associated with our planet and take up a solar orbit just like any asteroid. The suspicion it might be manmade , if nothing else, is the almost exact match between the earth's period (~ 365.25 days) and that of this object (366.1008685814365 +/- 0.005163 days). An object launched from earth (already 30 km/sec around the sun) will tend to have an orbit with a period close to that. We have detected 1 or 2 other proable launchers in heliocentric orbit tat were originally logged as asteroids (since the search programs identify objects in the sky, not what they actually are).

It was my understanding a certain amount of energy is necessary to move object A from Earth into Earth orbit x. More energy is needed to escape Earth's gravity and establish a new, independent, orbit around the Sun. How is "space junk" able to transition from Earth orbit into a Solar-centric orbit on its own?

Could it somehow be perturbed by other forces, such as the Moon? Other bits of junk? What would cause a bit of space junk to undetectably become free of Earth's orbit which could then give rise to such claims that this could be manmade?

Certainly they are perterbed, as is everything else in the solar system. The reason they are lost, is because, while we track the spacecraft that are launched, the launch vehicles aren't tracked...they just go on their merry way.

In fact, what we actually do when we launch an interplanetary spacecraft is that we put it into a heliocentric orbit that intersects another body at a future time.

This is the closest approach to any obeject in the solar system until at least 2137 (as far as the search goes)

 

[CalliArcale]

Re: 2010 AL30

Question(s):

I'm curious as to how there could be any question regarding this object's origins. I understand the reasoning that because it seems to share a similar orbit, it could possibly be manmade. But, that begs the question, if it had a chance to be manmade, how could it have gotten there in the first place and achieved its own orbit about the Sun?

It was my understanding a certain amount of energy is necessary to move object A from Earth into Earth orbit x. More energy is needed to escape Earth's gravity and establish a new, independent, orbit around the Sun. How is "space junk" able to transition from Earth orbit into a Solar-centric orbit on its own?

Could it somehow be perturbed by other forces, such as the Moon? Other bits of junk? What would cause a bit of space junk to undetectably become free of Earth's orbit which could then give rise to such claims that this could be manmade?

Well, there are a few things to remember:

1) There are indeed rocket stages which have achieved Earth escape velocity. These would be the upper stages of rockets which launched interplanetary probes. For instance, the Star 48B booster used as the last stage of the rocket delivering New Horizons to its solar escape trajectory is itself on a solar escape trajectory. In fact, the booster passed Jupiter before New Horizons did.

2) It is entirely possible for objects orbiting the Earth to wander away from it. This has in fact been observed; the S-IVB upper stage from Apollo 12 was orbiting the Earth after the Apollo mission, but disappeared a few years later. It reappeared a few years ago, again orbiting the Earth, and was observed to leave the Earth system again by passing through a Lagrange point, which acts as a sort of gravitational keyhole. (The booster was provisionally designated asteroid J002E3 until its identity was deduced.) It requires very little energy to shift between Earth orbit and Solar orbit if you can arrange for your spacecraft to pass through one of these points. This object seems to be too small to be another S-IVB, but there are many other rockets that have been launched high enough to theoretically experience this.

3) Rocket stages are light and irregular, by the standards of asteroids, so they are very vulnerable to forces that can perturb their orbits. Venting of residual propellant early on is an obvious one. Uneven solar heating is another, as is the Moon's gravity. The odds of a spent booster staying where it is put are pretty low.

 

[Woggles]

With all this talk about 2010 AL30

I was wondering if there are spent rocket stages orbiting the sun and if so what is the likelihood of them returning to earth?

Paul

 

[Solifugae]

If, for the sake of argument, it turns out to be a nickle-iron asteroid, what sort of crater (on land) might it produce?

I'm not sure of the asteroid's speed, but assuming a typical 17km/s and other typical specifics (such as impact angle), your hypothetical gets this:

Distance from Impact: 1.00 km = 0.62 miles
Projectile Diameter: 11.00 m = 36.08 ft = 0.01 miles
Projectile Density: 8000 kg/m3
Impact Velocity: 17.00 km/s = 10.56 miles/s
Impact Angle: 45 degrees
Target Density: 2500 kg/m3
Target Type: Sedimentary Rock

Energy before atmospheric entry: 8.06 x 1014 Joules = 192.46 KiloTons TNT
The average interval between impacts of this size somewhere on Earth is 30.9 years

The projectile begins to breakup at an altitude of 13700 meters = 44800 ft
The projectile bursts into a cloud of fragments at an altitude of 7180 meters = 23500 ft
The residual velocity of the projectile fragments after the burst is 7.28 km/s = 4.52 miles/s
The energy of the airburst is 6.58 x 1014 Joules = 0.16 x 10^0 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.

So the result is a 160 Kiloton airburst at just over 7km. Airblast is not noticeable (The overpressure is less than 1 Pa)

Using porous rock instead of iron, it bursts at 36.4km with 140 Kilotons of energy. Neither scenario is dangerous, and if I remember correctly, last year, an asteroid of similar size exploded over Indonesia. It would be more of a scientific interest than a danger, even if iron.

The initial estimate included the possibility that it was 25m. An iron asteroid of this size is tended to where it can strike the ground and create a significant crater.

 

[CalliArcale]

Re: With all this talk about 2010 AL30

I was wondering if there are spent rocket stages orbiting the sun and if so what is the likelihood of them returning to earth?

Paul

There are definitely spent rocket stages out there. Apollo 12's S-IVB returned to the Earth system, but did not impact the Earth, and eventually left again. These objects are not tracked -- indeed, because of their small size, they are virtually impossible to track. So they're pretty much lost. This makes it hard to estimate the risk any will return to the Earth, but if they do, odds are they'll be totally harmless. They have very little mass, and at the speed they'd be entering, they'd burn up pretty well.

 

[CalliArcale]

This blog posting has an interesting idea. Though the author initially leans towards the idea that it is natural, he ran the numbers and found that it is remarkably (almost eerily) consistent with the Fregat upper stage used to launch Venus Express in November 2005.

Close Asteroid Encounter Tomorrow

 

[MeteorWayne]

I suggested that 2 days ago (though without as rigorous a proof)

 

[a_lost_packet_]

Re: 2010 AL30

Thanks for the answers MW and Calli!

I just didn't consider that we're not only filling our sky with space-junk but, littering the rest of the solar system as well.

Thanks for stories about specific pieces of refuse, Calli. You know, really, there are stories there... A piece of man-made material goes off on its own adventure, unlamented by its creators? Sort of captivating, in a heart-on-your-sleeve way.

Is there a special catalog prefix or a reference for these bits and pieces of space junk that are blazing their own trail around our solar system? I'd like to find out more about these accidental explorers.

 

[CalliArcale]

Sorry, MW; I sometimes suffer from reading comprehension fail.

ALP: As far as I know, there is no special prefix affixed to these. In fact, if positively identified, they shouldn't qualify for an asteroid designation at all. And nobody tracks them out there. It's not like low Earth orbit, where US Space Command tracks everything they can (though not with sufficient resolution to accurately predict collisions). Even what is believed to be the Apollo 12 S-IVB is once again lost. An orbit has been computed for it, and I'm sure people will try to observe it the next time it is close enough to be seen. But for the most part, these things are lost.

I'd love it if there were a catalog of them all, but I've yet to find such a beast.

 

[MeteorWayne]

Not really, a_l_p. Once they are lost, we only learn about them again when they are found by the existing asteroid search programs, where they are given the temproray yyyy-halfmonth/order designation. If someone does the calculations we can ID them, but AFAIK, they will always carry the small solar system body designation.