Asteroid 2000 YA...A question.

I'd gone by and checked Spaceweater, and noticed 2000 YA as one we have passing close (in cosmic terms) around Christmas. What got my curiosity to check further was the fact it was highlighted, yet outside the 1 LD that I notice they usually highlight one. This is by no means meant to be a "Watch out, doom is coming!" type thread. I had gone looking at the JPL database to see if I could see anything unusual that would explain the highlight though. I found this:

2011-Dec-18 00:00 0.06557130563679 -13.7708744 -0.36758
2011-Dec-19 00:00 0.05764056537943 -13.6900388 -1.25648
2011-Dec-20 00:00 0.04975801953204 -13.6027874 -2.42696
2011-Dec-21 00:00 0.04192999556562 -13.4987798 -4.03397
2011-Dec-22 00:00 0.03417190781705 -13.3548464 -6.37037
2011-Dec-23 00:00 0.02652131350735 -13.1104486 -10.05891
2011-Dec-24 00:00 0.01908114776717 -12.5685784 -16.66260
2011-Dec-25 00:00 0.01221028647675 -10.8499152 -31.10317
2011-Dec-26 00:00 0.00760919562476 -3.3423063 -69.73484
2011-Dec-27 00:00 0.00950203453553 8.5771040 -56.86656
2011-Dec-28 00:00 0.01568969164021 12.0099370 -33.96692
2011-Dec-29 00:00 0.02292729352425 12.8927871 -24.67052
2011-Dec-30 00:00 0.03048227714789 13.2277558 -19.88819
2011-Dec-31 00:00 0.03817492770316 13.3980630 -17.00686
2012-Jan-01 00:00 0.04594530607208 13.5061048 -15.08555

I wonder if someone might be able to explain the last column there. The first is date/time group, second is observable range (It never comes terribly close even if the orbit diagram does look interesting) but the last is Plane Angle.

I've looked at a bunch of these since Elenin became a topic of real interest a couple months back, and I'm sure there is some reasonable explanation, but I've yet to see another run of angle numbers jump so dramatically. I'm used to seeing a smooth, logical progression in one direct or the other and slowly working up and down the numbers over time.

Why would this one jump that way? I'd thought about distance...again, this never gets all that close and it made a closer pass shortly after it was discovered that didn't show jumping numbers like that?

I'm just curious and looking to understand. Thanks!



Notation: I wanted to come back and add this was set for Geocentric Center (Code 500) for Earth as the observation point:

Ephemeris Type: OBSERVER
Target Body: Asteroid (2000 YA)
Observer Location: Geocentric [500]
Time Span: Start=2011-10-01, Stop=2012-01-01, Step=1 d
Table Settings: QUANTITIES=20,28
Display/Output: default (formatted HTML)

It occurred to me that without that minor detail, a simple setting mistake like a specific observatory for observor point, would explain a wild fluctuation. That wasn't the case. The numbers prior to this (As the date range up there shows I copied the block out of) was the normal, slow and steady progression moving toward crossing the plane into negative numbers....Until where I started the above block. Even Elenin (It's still in there...) shows a steady progression right through it's Earth pass for plane angle. Oh well... Maybe a glitch in the data set?

..check this coordinates RA 0h 03m 47.03s - DEC 5 40`53.57" on Google sky , there is a big red X ?!?!?!, the same as to the guy who put a video with the possible impact zone on earth!!!(with an big red X).....wtf is going on , who is playng with the google ????! , and why??

The truth is we're all gonna die!!!!!

and dont lie every guy that makes these threads is hoping for that.

BIG DOOM / SLAP UP THE FACE.

/badboy

Yea edit -- Someone tell me off.


2nd edit - took the prick part out, that wasn,t fair.

I'm not exactly sure how you got to what you are showing, (link would help), but I got a smooth progression here on the more accurate Horizons web interface.

When I hit the JPL close-approach data link by the orbital diagram we all know and love I got it's close approach parameters every approach, meaning one reading for the year of each close approach, but I clearly see the dates on your visual so you got me.

Originally posted by Illustronic
I'm not exactly sure how you got to what you are showing, (link would help), but I got a smooth progression here on the more accurate Horizons web interface.

When I hit the JPL close-approach data link by the orbital diagram we all know and love I got it's close approach parameters every approach, meaning one reading for the year of each close approach, but I clearly see the dates on your visual so you got me.

That is odd.... That is why I came back to add the settings details to my original post. Those are the settings as entered into the JPL Horizons Database and the late Dec 2011 Ephemeris numbers that it generated for me. It still is as of now, though I Scrapbooked the page just for future reference in case it's a glitch that gets corrected. That is why I came by here to ask. I figure there are people browsing these forums that have spent years looking at these kinds of data sets, not the mere months I've played with learning about it. The display strikes me as odd, nothing beyond that.

By the way...I've been playing with the Orbit diagram to get the best view and it looks like this comes from slightly below Earth and passes to a position above us right around it's pass date. Unfortunately, that leaves me more confused, not less as to the number progression. Perhaps I'm just badly misunderstanding what "Orbital Plane" is on the horizons ephemeris displays..In which case I'm anxious to hear that as well, should that be the explanation. Oh well... Nothing ventured, nothing learned.

Originally posted by Wrabbit2000
By the way...I've been playing with the Orbit diagram to get the best view and it looks like this comes from slightly below Earth and passes to a position above us right around it's pass date. Unfortunately, that leaves me more confused, not less as to the number progression. Perhaps I'm just badly misunderstanding what "Orbital Plane" is on the horizons ephemeris displays..In which case I'm anxious to hear that as well, should that be the explanation. Oh well... Nothing ventured, nothing learned.

The plane angle is the angle between the observer (in this case, your settings make that the center of the Earth) and the plane of the object's orbit. At the point of closest approach to the Earth, the plane angle is going to be at a maximum (or minimum, depending on if the object approaches from above or below the Earth's orbital plane).

Plug in some of the other near-earth objects. You'll find that surrounding whatever the date of closest approach, the plane angle rapidly increases (or decreases), then does the oposite.

reply to post by nataylor

I went back and looked at other objects like Elenin, Apophis and some random ones of the long NEO chart JPL/NASA maintain and you're right in that I saw a bit of variation on most, but a fairly minor one compared to this. Oh well, what you're saying makes sense, there must just be a quirk of the angles and trajectories involved here I'm not seeing. Math at that level isn't just a weak point, it isn't something I do at all.

To Charter: Actually, no, I don't have doom in mind for making the thread at all. This was another that could come right into the atmosphere for all I'd care and at only 80 meters? Heck, it might actually leave something large enough to bounce off a tin roof by the time it got to the ground..lol. One of these days though, the track might actually show a problem and it never hurts to know what a big variation means on a harmless example, right?

Originally posted by sabalsis1972
..check this coordinates RA 0h 03m 47.03s - DEC 5 40`53.57" on Google sky , there is a big red X ?!?!?!, the same as to the guy who put a video with the possible impact zone on earth!!!(with an big red X).....wtf is going on , who is playng with the google ????! , and why??

oh nooooooooossss

not with the Google Earth X.jpg plssssss

that is only showing you the icon image file is not found