The planetary-defense tag has the current (my) awkwardly-written description.
related to the defense of a planet from a major destructive event such as an impact, or searches for or studies of objects (e.g. asteroids, comets or other near earth objects) that potentially pose such a planetary threat
In order to improve this it would be good to better define "defense".
- What are all the activities related to defending planets against impacts from things like asteroids or comets? Are they only things like "identification", "tracking", and "deflection" or are there others?
- What are all the threats that can potentially be foreseen for which a defense might exist currently or in the foreseeable future? Are they only impacts of near Earth (or other planet) asteroids, or do comets or other near Earth objects count? Anything else?
- Including links to relevant Q&A here and in Astronomy SE is great.
- planetary-protection is something different.