This handout artist's concept provided by NASA/JPL shows the Comet Siding Spring approaching Mars, shown with NASAs orbiters preparing to make science observations of this unique encounter. A pristine distant comet created a once-in-eight-million-year fireworks show on Mars and no humans were there to witness it. But new NASA data from satellites circling Mars released Friday shows that on Oct. 19 when Comet Siding Spring skimmed the red planet, tons of comet dust bombarded the Martian sky with thousands of fireballs an hour. It warped the Martian atmosphere leaving all sorts of metals and an eerie yellow afterglow. (AP Photo/NASA/JPL)
WASHINGTON – A pristine distant comet created a once-in-8-million-year fireworks show above Mars last month. But no one got to see it live.