<P> Martian dust is reddish mostly due to the spectral properties of nanophase ferric oxides ( npOx ) that tend to dominate in the visible spectrum . The specific npOx minerals have not been fully constrained , but nanocrystalline red hematite ( α - Fe O ) may be the volumetrically dominant one , at least at the less than 100 μm sampling depth of infrared remote sensors such as the Mars Express OMEGA instrument . The rest of the iron in the dust , perhaps as much as 50 % of the mass , may be in titanium enriched magnetite ( Fe O ) . Magnetite is usually black in colour with a black streak , and does not contribute to the reddish hue of dust . </P>
<P> Martian dust is reddish mostly due to the spectral properties of nanophase ferric oxides ( npOx ) that tend to dominate in the visible spectrum . The specific npOx minerals have not been fully constrained , but nanocrystalline red hematite ( α - Fe O ) may be the volumetrically dominant one , at least at the less than 100 μm sampling depth of infrared remote sensors such as the Mars Express OMEGA instrument . The rest of the iron in the dust , perhaps as much as 50 % of the mass , may be in titanium enriched magnetite ( Fe O ) . Magnetite is usually black in colour with a black streak , and does not contribute to the reddish hue of dust . </P>
where did the iron on mars come from
where did the iron on mars come from
titanium enriched magnetite
titanium enriched magnetite