Comet Siding Spring’s close flyby of Mars last month dumped several tons of primordial dust into the thin martian atmosphere, likely creating a brief but spectacular meteor shower with thousands of shooting stars had any astronauts been there to see it, scientists said.
An international fleet of five Mars orbiters and two rovers will have ringside seats when a mountain-size comet streaks by on Oct. 19, passing within a scant 87,000 miles of the red planet at a blistering 126,000 mph.