Mars Red-Faced Without Water
The Martians are singing How dry I am. Scientists have a new explanation for how Mars turned red without water: it’s just dry dust tumbling in the wind. This new hypothesis was announced by Live Science, Science Daily, New Scientist, and Space.com, based on a presentation at the European Planetary Science Congress last week.1
This has been dubbed a “surprising” new theory. Why? Because for many years scientists thought that water was required to rust the iron in the rocks. Lab experiments at the Aarhus Mars Simulation Laboratory in Denmark have shown that quartz grains mixed with magnetite in a tumbler turn red in a few months as the surfaces wear down and oxygen atoms bind to the magnetite, forming reddish hematite. Because hematite is deep red in color, it doesn’t take much of it to color the dust red. These experiments do not rule out water on Mars; they just remove water as a requirement for staining the surface red.
If this is the source of the redness on Mars, it has implications for the age of the surface. Space.com said, “since the process can occur relatively quickly, it could be that the thin red layer of dust on Mars is somewhat new.” How new? Jonathan Merrison said “millions of years instead of billions of years.” His experiments, though, reduced the sand grains to dust in just seven months, and they turned red quickly when magnetite was added.
1. Merrison, Gunnlaugsson, Jensen and Nornberg, “Mineral alteration induced by sand transport; a source for the reddish colour of Martian dust,” Icarus (in press, published online 9/12/2009), doi:10.1016/j.icarus.2009.09.004.
The moyboys should be red-faced (moyboys: those recklessly spouting claims about “millions of years, billions of years”). Not only does this potentially undermine the astrobiologists’ hopes for water on Mars, it casts doubt on whether the surface is really billions of years old. Remember, even 100 million years is a tiny fraction of the assumed age of the solar system (A.S.S.). What color was Mars before? Yellow? Green? Purple? Why are we seeing the tail-end of a rapid process if Mars dried up billions of years ago and its sand grains have been tumbling around for eons? The truth is, they just don’t know. They weren’t there. The fact that a hypothesis this radical can upset everything previously believed about a planet should give one pause before accepting the next moyboy pronouncement on faith.