Planetary-Defense Comets

A Jupiter-family comet that began fragmenting in 1995 and has since broken into dozens of pieces — a rare chance to watch a comet disintegrate over successive returns.

A comet captured into orbit around Jupiter that was torn into more than 20 fragments by tidal forces and spectacularly impacted the planet in July 1994 — the first collision of Solar System bodies ever observed.

A long-period comet that made an exceptionally close pass of Mars in October 2014, observed up close by the fleet of Mars orbiters and rovers.