I was just wondering if any of you saw the impacts of Shoemaker/Levy-9 on Jupiter? I didn't own a telescope then. In fact I wasn't into observing then. I know I wasted the once-in-a-lifetime-chance to see the impact. But you never do know if it'll happen again.
Yes, two of the impacts occurred early evening on separate evenings here, and we were blessed with clear weather and good seeing. Several had the chance to watch with 12" f/5, 14" f/7 and 16" f/7 dobs, we were timing the impacts down to the second, and had a fine view of the impacts as they rotated into view.
Yes I think it was the most memorable thing I've ever seen. After Luis and Walter Alvarez publicised their theory based on geological evidence it wasn't fully accepted as the fate of the dinosaurs for several years but the SL9 impact:
- made it quite clear this would have been an extinction event on earth;
- finally nailed all arguments about what happened to the dinosaurs.
SL9 was found on a previous orbit in 1993 and was somewhat unremarkable, though the elements in the IAU circular indicated it would make a very close approach to Jupiter the next orbit. It wasn't until it was recovered in 1994 that Brian Marsden issued another circular with some excitement announcing it was going to be a head-on impact.
In this respect my generation were incredibly lucky to have the scientific tools and evidence to assemble "Big History", the astronomical and computing resources to have spotted SL9 previously, then recover it and determine the orbit so accurately not just to know it would impact, but the impact time for each fragment down to the second, and also so many amateurs able to see the impact sites for themselves.
Quite likely we will know well in advance of another - objects the size of SL9 are easily within reach of the professional oservatories and for each object known the professionals do determine its orbit to check for future collisions.
Edited by luxo II, 31 May 2020 - 06:56 AM.