2022-02-13, 01:56 PM
Phil, I know you already know this but for those that don't, Horizons has made it much easier today to hunt down that sort of information. Go to https://ssd.jpl.nasa.gov/tools/sbdb_lookup.html#/ then put in the rock designation or number and scroll down and click "show" on the Close Approach Data. You can now look far back as well as at future dates for not only our home planet but the Moon, other planets and several of the larger asteroids. I've used stand-alone specialty software to do that for years but now find it easier to let Horizons show me the work they have already done.
You can even get data for recent discoveries, even though they may have only 1 day arcs with reasonably low uncertainty with a couple dozen observations. I'm not sure why JPL calls 4-8 days reasonably low uncertainty!
Take the small rock 2022 CJ5 that scrapped my horizon a couple days ago just 31,221Km from my yard. Punch it in at Horizons to see that it had a similar close approach almost exactly 12 years ago. Cool stuff!
You can even get data for recent discoveries, even though they may have only 1 day arcs with reasonably low uncertainty with a couple dozen observations. I'm not sure why JPL calls 4-8 days reasonably low uncertainty!
Take the small rock 2022 CJ5 that scrapped my horizon a couple days ago just 31,221Km from my yard. Punch it in at Horizons to see that it had a similar close approach almost exactly 12 years ago. Cool stuff!