2020EF and 2020DP4 are moot. The bad boys are out there, lucky if you know ahead of time, nothing you can do about the ones you would know about that are relavant to and in your lifetime anyway.
https://en.wikipedia.org/wiki/Near-Earth_object https://cneos.jpl.nasa.gov/sentry/ https://cneos.jpl.nasa.gov/ca/ https://ssd.jpl.nasa.gov/
