> While more research is needed, the proposed timeline suggests that asteroids — including NEOs that pose a potential threat to Earth — may have much greater longevity than previously estimated.
The phrasing here is a little confusing. Is it just new that NEOs can be this old? What was the thinking before? That no asteroids could be that old? Or that no asteroids that old would ever come near Earth (if so, why)?
Am I missing some information (e.g. said meteorite was in some sort of unstable orb around Earth / the Sun for a long time)?
I believe the common thinking is that the giant gravity wells of Jupiter, Saturn, and the Sun are often considered a shield for the inner Solar System planets. Thus, given enough time (10 million years per the article) these wells attract and destroy a vast majority of free rocks, preventing them from threatening Earth.
But (my conjecture) if there's far more random junk flying around out there, that's going to force a re-think of how we guarantee the safety of space travel past the Moon.
The phrasing here is a little confusing. Is it just new that NEOs can be this old? What was the thinking before? That no asteroids could be that old? Or that no asteroids that old would ever come near Earth (if so, why)?
Am I missing some information (e.g. said meteorite was in some sort of unstable orb around Earth / the Sun for a long time)?