Mars Rocks Went to Comet 67P.

European Space Agency’s Rosetta spacecraft took this photo of  comet 67P. Image source with details:  imagearchives.esac.esa.int/picture.php?/8974/search/128 (archived in this album: imagearchives.esac.esa.int/index.php?/category/64)
Red box contains an apparent layer on Comet 67P. Such a layer is often found on Earth and on Mars. Many of such layers have been found on Comet 67P (see http://wretchfossil.blogspot.tw/2015/05/many-mars-rocks-found-on-presolar-comet.html). Such layers show Comet 67P originated from Mars and was not presolar (presolar: before the sun), for the following reasons:
1. The space is nearly vacuum. 
2. There is no magnetism/volcano/river/ocean/lake on the comet. 
3. Therefore, the comet cannot form numerous layers by itself. Such layers      should have been formed somewhere else.
4. In our solar system only Mars has the features of Comet 67P, which has ice, organics and layers of “rock”, but no magnetic fields (note 1). So, such layers should have come from Mars instead of other planets or moons or asteroids.  
5. Mars did not exist before the sun was formed.

Note 1: In our solar system, only Mars and Venus have no active magnetism. All other planets, all the moons and asteroids in our solar system have magnetic fields. Ref.: www.reddit.com/r/askscience/comments/1yehec/do_all_the_pl… 
and sunearthday.nasa.gov/2010/getinvolved/aa_wu_magneticmoons…