Celestia Forums

Has anyone heard anything about 1950DA that may collide with earth on March 16th 2880? There have been som e reports in Swedish news regarding this...

Would be nice to see its orbit in Celestia, has anyone got any data on it?

Keep up the excellent work, Chris et al.

/ Lars

Install this file:

http://www.shatters.net/celestia/files/neo.ssc

to add 1950 DA to the solar system. However, you won't be able to see March 16th, 2880 collision. I just have elliptical elements for the orbit, which aren't at all accurate over such a long time period.

--Chris

My personal guess is that this is a big hoax.
Small bodies have very cahotic orbits, on a so long time scale it can run for more than undreds BILLION of Km, to be sure that one of such body can hit the earth you should have a precision much better than 1/10Million.
Which is unbelivable.
I'd like to read a serious scientific work about that before to belive it.

Chris: Thanks, I'll have a look...

flym: Agreed, and being over 800 yrs dead I won't be that bothered by a crash if it would occur, or I'll at least have a distant view of it from (hopefully) above
Still, this is the best way of viewing it...

Slightly off-topic; Chris, is it or would it be possible to have "time-limited" data segments (for lack of better word) for (mainly) artificial satellites, so that one could view for example how the NEAR probe got from Earth all the way down to Eros, or for all the nice slingshots of Voyager... ? At least for NEAR I believe that there is quite a lot of this data around that would be fun to watch... Maybe in 1.5 or 2.0?

/ Lars

The Science article on the orbital integration of 1950 DA came out today. I have had an opportunity to read the article, and can say that the investigators involved took painstaking care to calculate the future position of the asteroid.

To begin, astrometric positions going back 50 years, in combination with radar astrometry (which is extremely precise) has reduced the errors in the orbital elements significantly. Numerous test particles were then placed in possible current positions for the asteroid (much smaller than a 1 arcsecond spread) and integrated forward. A very large number of effects, many not normally condsidered for orbital integration problems, were incorporated into the simulation. These incluse, galactic tide, error inthe numerical integration, mass loss from the sun, the non-spherical nature of the sun, gravitational effects of all of the planets as well as 61 additional asteroids which DA passes near during the time involved, uncertainty in the masses of the planets and these asteroids as well as the solar radiation pressure and the Yarkovsky effect. Needless to say, these are exhaustive calculations that reveal approximately a 1 in 300 to a 1 in 350 chance of an impact in 2880.

It is far from a hoax, and is a much more robust finding than the rather rushed announcements of impact solutions for 1997 XF11 and 1999 AN10 (which were quickly eliminated by additional observations). This is a very exhaustive work.

I would encourage anyone interested in this problem to look at the Science article. It is a scientific research paper, so some of the material is a little complex, but I think any generally literate individual (anyone who is using Celestia has to be generally literate) can understand the vast majority of what was done and what the findings are.

The part of this that scares me the most is not that a very good impact solution exists for this object, but that we won't be able to difinitively rule out an impact without exstensive physical studies of the asteroid, including more astrometry from the ground, more radar observations, spctral studies of the asteroid and probably most important, a spacecraft mission to determine the rotation direction and surface composition. The spaceccraft data will determine the magnitude of the Yarkovsky Effect on the asteroid, which could potentially push the asteroid such that is just misses the earth. It is likely that we won't know wether an impact will happen in any of our lifetimes....

Hope that this clarifies a bit for everyone. When the asteroid is brighter in the winter, we are planning to observe it as part of our NEA physical studies program here at the University of Western Ontario. This should provide the spectral data necesary to determine the surface composition.

Marshead

Just a question: what's the Mass of this asteroid?