Animations by
Michael Lentz
Released on October 14, 2014
On October 19, 2014, Mars will receive a first-time visitor from the outer fringes of the solar system. C/2013 A1, better known as Comet Siding Spring, has been traveling toward the inner solar system for millions of years, and will just miss Mars by a distance of 88,000 miles on October 19 (roughly one-third of the distance from the Earth to the Moon). These animations depict the flyby as seen from orbit above Mars, and as seen from the Martian surface. The blue portion of Comet Siding Spring's tail is composed of ionized gas swept away from the Sun by the solar wind. The gray portion is composed of heavier dust particles, which are moving at 33 miles per second relative to Mars.