Celestia Forums

I have tried to display the asteroid 2005 YU 55 as it is shown in the graphic at Space.com:

http://www.space.com/13512-huge-space-r ... aphic.html

but cannot get the orbits to align in the same way as they are shown in the graphic with the time in Celestia set to 2011Nov 8 20:53.23 UTC. The add-on I am using for the asteroid is either from Owen McQueen or Arlene Ducou, downloaded from the Celestia Motherload; I am not sure which add-on actually contained 2005 YU 55. Is the data wrong for this add - on? I am not even an amateur astronomer so I do not know how to use any coordinates, just trying to line things up manually, so it is very possible I am doing something wrong. I uploaded a screen shot of the closest I could come to matching the graphic.

Also, the exact location of the asteroid seems to be incorrect for the add-on.

The best way to add this (or other) asteroid is to use
mpcorb2ssc.exe
http://fisica.cab.cnea.gov.ar/estadisti ... n/celestia

and asteroid database
MPCORB.DAT
http://www.minorplanetcenter.net/iau/MPCORB.html


Put MPCORB.DAT into folder where is mpcorb2ssc.exe and run EXE
type 1 then name K05Y55U

Here is result:

Thanks for the reply.

I used your resource and even though now, the position of the asteroid seems closer in accuracy, there seems to be a problem with the orbit... or again, it could be my mistake. As I said earlier, I am not even an amateur astronomer and my tech aptitude is probably much lower than many of those who post here.

Attached is a screen shot from of the 2005YU55 earth flyby using the script generated by MPCORB2SSC 1.1 with MPCORB.DAT. I also removed all the previous asteroid files from Celestia I used in the previous screenshot.

Thanks for the resource.

I made a short video showing the flyby: 2005 YU55 visits Earth

Closest approach happens at 23:40 UT as seen from somewhere in the surface of Earth facing the asteroid (I just "went to" the surface and checked the distance). It seems pretty close to what the observatories said.

The weird thing when seeing in Celestia following Earth, is that the asteroid does not seem to move in the direction of it's orbit! This confused me at first, but it is of course because the Earth is moving too. If you back up a little and follow the Sun instead, you will see both Earth and asteroid, each moving along their orbits, and passing by.

I just made another video showing the flyby in a reference frame following the Sun: another view of the flyby of 2005 YU55 (this one shows the time, which I cut out in the previous one).

Thanks for using my script!

Guillermo

abramson wrote:Thanks for using my script!

Guillermo

So we thanks for mpcorb2ssc.exe

Adam