ALBUFEIRA

Face à passagem do cometa C/2013 A1 nas proximidades do planeta Marte, se fosse marciano e seguindo a tendência dos últimos cálculos da sua trajectória, começaria desde já a rezar. Na sua viagem de mais de um milhão de anos através do Universo, a distância inicial de passagem do cometa relativamente à superfície de Marte, já evolui de 300.000 km para pouco mais de 100.000 km, dando razão àqueles que falam de uma possível colisão. Mas os cálculos continuam.

A close encounter between Mars and Comet C/2013 A1 (Siding Spring) in 2014 is creating both opportunity and anxiety in scientific circles. Scientists are in the early stages of assembling a comet-watching campaign that uses a spacecraft currently orbiting the Red Planet, as well as rovers on the Martian surface.

Scientists are also investigating what techniques could be used to prevent cometary debris from hitting Mars-orbiting spacecraft as the comet and planet converge.

The Mars-bound comet was discovered by Rob McNaught on Jan. 3 at Siding Spring Observatory in Australia. Scientists estimate that this comet arrived from our solar system’s distant Oort cloud and has been on a more than 1-million-year journey. The comet could contain volatile gases that short-period comets often lack due to their frequent returns to the sun’s neighbourhood.

Scientists expect the comet’s closest approach to Mars to occur on Oct. 19, 2014, at about 11:45 a.m. PDT (18:45 GTM).

At that time, the comet will be on the sunward side of Mars. The comet and its tail should be a stunning sight in the predawn Martian sky just before the closest approach, as well as in the post-dusk sky just after the closest approach.

The latest orbital plot places the comet’s closest approach to Mars a little farther out than previously estimated — at about 73,000 miles (117,000 kilometres) from the surface of the Red Planet.

(retirado de artigo – Leonard David – space.com)