spacetoday.net: Comet flyby created Martian meteor shower

Posted: Sun, Nov 9, 2014, 7:39 PM ET (0039 GMT)
Comet Siding Spring flies past Mars (NASA illus.)

The closely flyby of a comet to Mars last month created an "impressive" meteor shower in the planet's atmosphere, according to data from several spacecraft in the vicinity of the planet. Comet C/2013 A1 Siding Spring passed less than 140,000 kilometers of the Red Planet on Oct. 19, and dust from the comet impacted the Martian atmosphere. Scientists examining data from Martian orbiters, placed on the other side of the planet from the comet during the time of closest approach, said the dust created "significant temporary changes" to the planet's upper atmosphere, including a temporary, but strong, layer of ions in the Martian ionosphere. Images of the comet's nucleus taken by the Mars Reconnaissance Orbiter spacecraft showed it to be less than two kilometers across, smaller than expected.