Mystery Spheres on Mars Finally Identified

Space.com ^ | 17 March 2004 | Leonard David

[ElkGroveDan]

Scientists have learned the composition of the mysterious sphere-shaped objects scattered across the crater floor at Meridiani Planum, the landing site of the Opportunity Mars rover.

By using a Mössbauer Spectrometer mounted on Opportunity's robot arm, a patch of the tiny spherules -- also called "blueberries," although they aren't blue -- received close examination and have now been identified as hematite.

The spectrometer is designed to study minerals that contain iron, which are common on the Martian surface. Also used to pin down the makeup of the spherules was the rover's Mini-Thermal Emission Spectrometer, a science instrument that can recognize minerals formed in water.

Meridiani: shallow lake?

This new evidence further supports the hypothesis that the hematite mineral was likely formed in a past standing body of water. The Meridiani area, it is thought, was once a shallow lake.

Once Opportunity wheels itself out of its current shallow crater site, scientists expect the hematite-rich spherules to litter the landscape at Meridiani Planum.

Philip Christensen, a Mars Exploration Rover scientist from Arizona State University in Tempe, announced the finding yesterday at the 35th annual Lunar and Planetary Science Conference being held in Houston, Texas.

Formation via precipitation

"This finding further supports the hypothesis that these interesting 'Mars balls' are actually sedimentary concretions, rather than any of the other working hypotheses," said James Garvin, Lead Scientist for Mars Exploration and the Moon at NASA Headquarters in Washington, D.C.

There have been a variety of contending theories for what may have caused the unusual mineralogy at Meridiani, including volcanic causes.

Garvin told SPACE.com that this latest finding strongly supports the view that the rocks in the outcrop at Meridiani have been modified by water -- a determination made already through other research at the site.

"Hematite as a major compositional phase in the spherules supports their formation via precipitation, rather than as impact-related fallout," Garvin said.

"So, the story is getting better... and multiple lines of independent evidence support water-related chemical 'processing' of the rocks," Garvin added. "Now all we have to do is figure out what made the rocks in the first place and how long the water may have been involved in the 'soakings'. What a fun time!"

[XBob]

56 - sorry you are 'slow' tonight. Have some coffee.

I posted, about manganese/iron nodules on our sea bed, and how they are formed, layer on layer, and into little spheres, from minerals precipitating out of the water.

It seems like a likely way of forming similar 'berries' on Mars. And while most 'usable' nodules on Earth are much larger (the size of potatoes), there are many small ones too. And with the Earth seas being around much longer, that could account for the size difference.

Just trying to throw an idea into the 'thinking' pot here for FReepers to 'stew' over, hypothesizing.

[XBob]

56 - In fact, look at the picture of various nodules I posted in #52, the third one down on the right looks almost exactly like the 'Mars berries'.

[general_re]

It seems like a likely way of forming similar 'berries' on Mars.

I had some coffee this morning and realized that this was more or less your point, but thanks for clarifying. Anyway, whenever someone talks about manganese nodules on the ocean bed, I get sidetracked into thinking about Project Jennifer for some reason ;)

[XBob]

I remember that, but forgot about the nodules.

It seems to me there were 3 'glomar' ships built, and several trips (mostly successful finally) to raise the soviet submarine.

They also worked in the South China sea, just off the coast of Vietnam for some reason, which I never heard revealed.

[dr_who_2]

So far as I can make out, there aren't even any cretins, invertebrates, or lawyers on Mars.