Just tuned in to the NASA webcast. They have started the Q & A after the presentation. I'm in a rush as I have to start work but from the first Qs looks like they have found C Carbonate. Possibly around 7 to 8% according to prelim analysis. Possible P Silicates found in trace amounts. Boyton - if organics there then not v much.

Suggestive of past interaction with water. How does this square with perchorate findings (little or no water)?

This data is enough to 'start rewriting the book of Martian geochem'.

Annoying but I've got to go...... but sounds like exciting stuff. I'm sure we'll be having a full discussion on this and Emily and AJS Rayl from Planetary Society will keep us up to date........

Actually, Hugh, you've captured nearly all the news from this press briefing! The neatest bit I heard was the presentation of the MET team showing evidence for high-altitude snow falling -- they said they'll keep watching to see if any of it reaches the ground.

--Emily

Release: JPL Phoenix Mission News: NASA Mars Lander Sees Falling Snow, Soil Data Suggest Liquid Past (September 29)

My own inept live transcript -- with connection glitches -- begins at BAUT Forum article in topic Phoenix on Mars: Extended Mission

Virga!!

I missed the conference sadly. Was there a not as to what kind of snow (Water vs Dry Ice)?

[edit: seeing the link above, one seems left at the assumption of water ice snow, without such being explicitly stated.]



-- Pertinax

"For nearly three months after landing, the sun never went below the horizon at our landing site," said Barry Goldstein, JPL Phoenix project manager. "Now it is gone for more than four hours each night, and the output from our solar panels is dropping each week. Before the end of October, there won't be enough energy to keep using the robotic arm."

Wow, I guess we will have to swallow hard and admit that all good things do indeed come to an end. Phoenix is one of the few "intermediate" lifetime explorers we have been following. There were some probes with very short (and planned to be so) lifetimes, such as the Huygens probe. And we have been spoiled with our hardy friends farther south on Mars, as well as such veterans as Cassini and the Voyagers. In this case, I find myself thinking, "Phoenix, we hardly knew ye!"

Reading the prior discussions hypothesizing about someday finding Phoenix encased in ice reminded me of the final act of Steven Spielberg's "A.I.", when the robots in the far future find our hero in the frozen ocean off of what was once New York. (Hope I didn't spoil the movie for anyone!)

Can't find the reference now, but I saw it described yesterday as "diamond dust" -

"Diamond dust - This is the name given to the sparkling clouds of tiny ice crystals that appear to fall out of a cloudless sky. The ice crystals can disappear before they reach the ground through a process called sublimation."

Mmh, does the calcium carbonate either rule out the 'acid water ancient Mars' picture or the 'Mars was wet but not anymore' picture?

They also talked about the possibility of a wet ground when the martian axis was more tilted towards the Sun. But Phoenix is actually at a quite high latitude. How may the Phoenix findings extrapolate to the meridional Northern Plains, with warmer temperatures, if there's any ice under the soil?

For example:
http://marsoweb.nas.nasa.gov/HiRISE/hirise...SP_002439_2265/

Edit: I totally forgot about this... this has been one of my favourite HiRISE images since the beggining of the mission:

http://marsoweb.nas.nasa.gov/HiRISE/hirise...RA_000856_2265/

Back then I even cropped this section because there was a bright spot that really looked like exposed ice. It even could make sense after seeing Holy Cow:

Well.. the article says "NASA's Phoenix Mars Lander has detected snow falling from Martian clouds."
so not from a cloudless sky. It seems to be real snow.

So the soil is now bone dry but has minerals in it that must have formed in the presence of water? Interesting. I'd got the impression that the warming due to mars axial tilt was to slow for the ice to melt , it would simply sublimate and re-condense somewhere else without ever reaching the liquid phase. Is this evidence against that, or could there have been melting from volcanic or impact heat that lasted long enough to leave this impression? There is a large crater just down the plain. How long does the observed amount of calcium carbonate take to form? Mars throws us more mysteries....

No information asked or volunteered about nitrogen content in the soil. Since nitrogen seems to be essential for habitability on Earth, why does no one mention this issue? Has TEGA detected any nitrogen?

For some reason a couple of the neat graphics they showed at the briefing haven't made it to the mission websites yet, but I got them from the PIO office and they're in my update now. Falling snow!

--Emily

All..

today's (September 29th, 08) Phoenix press conference can be seen here
http://www.space-multimedia.nl.eu.org/inde...13&Itemid=1

Craig

They note that Phoenix is on a reasonably recent ejecta layer and that the ground is bone dry. (We really need a new word to describe just how dry this is). So the carbonates and clays were almost certainly excavated from the crater and the discovery would seem to be a strong indicator of a warmer wetter far past, but little to do with the current environment in this area, or the salty, acid sulphate environment seen elsewhere.

I'm not sure what the fuss is concerning the high altitude snow. As the temperature drops the vapour must freeze out. Snow, both water and CO2 has been referenced numerous times in analysis of both poles. Interesting in that the LIDAR got such compelling images but surely the 'diamond dust effect' or snow was an expected outcome? I also thought that the Atacama perchlorates were thought to have been formed as aerosols so again no real surprises?

The big surprise is no organics or superoxides. Since organics should be falling from space on a fairly regular basis where are they? I just get the feeling that any real info is being held back for conference papers and learned contributions to Nature, and I look forward to those with great anticipation. The briefing did not in fact say very much at all.

*cough*cough*
Aussie, I really don't think that the Phoenix team is known for 'holding information back'.
As demonstrated recently, they are VERY open when it comes to data and their scientific process.
If they had something important to tell us, they'd say so.

Also, I think that the 'fuss over snow' is justified.
They know that something like "it's snowing on Mars" is media and public outreach gold.
Are you going to get any attention if you just say "we found calcium carbonate".
A snow report is a hook to hang the rest of your science on.

Great and open outreach!

Astro0

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