I hear that. I've made a garden from Piedmont gray clay (like red clay but lacking in iron). 200 million years of NOT MUCH HAPPENING leached most the nutrients out of the native soil. And it's a natural pH 4.5 as well.

But I'll bet Mars doesn't have mosquitos, ticks, Japanese beetles, squirrels, or deer.

Sign me up.

Daisy World, here we come!

On a world with a probable history of a magma ocean and with well differentiated crust, mantle and core, one problem I've thought of won't be a problem.

Heavy metals.

Would the heavy metal content of a chondritic soil or more specifically a carbonaceous chondrite soil cause problems?

In California, there's serpentinite and related terrains formed of up-thrust mangled bits of upper mantle. Lots of plants DO NOT like to grow there. They have decidedly special biomes growing on them. CChondrite soils would be worse!

I don't know much about heavy-metal content of chondrites. Do you have references?

Although the Mar's convective mantle engine appears to be inactive nowadays, it may have been more active earlier. And certainly Mars has been hot and is differentiated.

--Bill

Full inline quote removed - Admin.

An Undifferentiated Chondrite would have much more heavy metal content. All those Siderophile and chalcophile elements are concentrated in the core of the Earth.

Also, look at the fundamental differences of Earth and Mars. However you look at the situation, the bulk density is different, the chemical activity is different. Mars is made of different stuff then Earth is, and then it evolved different again. Never make the mistake of assuming that Mars is "like Earth"...

That's sort of a matter of degree, isn't it, Nick? In the great range of like to unlike, Mars is far more like Earth than it is, say, like Jupiter. Or Neptune. Or even Titan.

-the other Doug

Just saw this article in the Telegraph:



But as I understood the press telecon, they've found certain trace elements, not all the nutrients necessary for growing plants (i.e., NPK). Seems like the press is being "led down the garden path" by these press conferences.

Major elements and trace elements (in order), required for plant growth:

C. HOPKNS CaFe Mg B Mn CuZn ClMo

("C. Hopkins Cafe, managed by mine cousin Clomo.")

It will be really interesting to see the quantitification of trace elements detected (I assume in ppm).

And if there are heavy metals? No problem. Just plant ferns just before your martian bean crop as in this article/video.
(Bad luck that most ferns are acid-loving, but maidenhair ferns like pH 7-8)

-Mike

The bizarre flora of long isolated New Caledonia is a fascinating example of long term adaptation to soils rich in often nasty heavy metals and other baddies.

p

...cool mnemonic, Mike!

This whole spin-up is a bit unfortunate, though; expecting to be bombarded with questions from my co-workers tomorrow (been gone for the last 2 weeks attending a class). After all, plants have been grown in lunar soil, but that does not imply that life arose on the Moon, merely that terrestrial life needs certain stuff to exist & the Moon happens to have it. Big difference.

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Did they deliver at the weekend a sample to the optical microscope or to the Wet Chemistry Laboratory? if not,when do they plan to do this?

There is a dark image here, but by adjusting brightness and contrast, I think I can just see some material in the 2nd WCL cell:
http://phoenix.lpl.arizona.edu/images/gallery/lg_10401.jpg

I guess the RAC view is better :-)

http://phoenix.lpl.arizona.edu/images/gallery/lg_10339.jpg

There seems to be some stuff at least on the side of the collector, but I wonder if it's enough.

I presume this is from the soil/ice interface layer?

"
July 7, 2008 -- NASA's Phoenix Mars Lander used its Robotic Arm to deliver a second sample of soil for analysis by the spacecraft's wet chemistry laboratory, data received from Phoenix on Sunday night confirmed. "


http://phoenix.lpl.arizona.edu/07_07_pr.php

Some tidbits from the July 1st entry of Dr Tom Pike's diary for the BBC News website :

and

Before touchdown, Dr. Quinn was quoted in an article at the SETI site :


So,
If the alkaline pH supports the "superoxides in soil" Viking explanation, why were teran gardeners encouraged to have high hopes for martian asparagus ? Anyone care to enlighten us ?

I'd guess that the alkaline soil is one piece of evidence in favour of the superoxide idea, but there are a lot more to be found before it's proven- such as the superoxides themselves! Over simplified reporting, although i may be judging prematurely, having not read the thing..

Edit: now I've read it I think its less oversimplification, more two tentative interpretations on preliminary results, as always more data needed!

Perhaps because it's easier to sell a Mars program as a "search for life" rather than as a "search for superoxides"?

Unless you show that the latter "get your laundry superbright!! "


It's tough waiting for data.