Sent in by William. At https://phys.org/print425205777.html … going back to 2014, when Comet Siding Spring passed within 140,000 miles from Mars, one third of the distance between Earth and the Moon, we learn another factor was at play. The comet deposited a large amount of debris on the Martian surface as spacecraft in the Mars vicinity witnessed the largest meteor shower in recorded history. This sounds like classic Velikovsky – as in Worlds in Collision and a close approach of a comet. Scientists have since found that a very powerful coronal mass ejection launched by the Sun also arrived at Mars just 44 hours prior to the comet – which created significant disturbances in the Martian atmosphere. As such, it complicates an analysis of the data. Hence, we have the sequence of CME followed by the coma of the comet enveloping the Martian atmosphere for several hours. On top of this the meteor shower.