At https://phys.org/print410012455.html … an asteroid orbiting the 'wrong way' around the Sun has been risking a collision it would seem, but somehow they always miss each other (or that is what we are being told as the asteroid has just got to be millions of years of age). The asteroid has a retrograde orbit around the sun and shares its orbital space with Jupiter – a rather large object to repeatedly miss. It emerges that Halley's Comet also has a retrograde orbit. Is does this imply it is a chip off the old block?
The story is also at https://tallbloke.wordpress.com/2017/03/30/wrong-way-asteroid-plays-chic… … and the comments are worth browsing. Old Brew says Jupiter's 'gravity' deflects the asteroid at each pass so as to allow them to continue passing each other safely. He asks, this doesn't appear to be the way gravity is supposed to work. A bright spark chips in with a two word comment, 'dark gravity'. A touch of humour but are we to add dark gravity to dark matter and dark energy?
