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Posted by: RNeuhaus Jun 8 2006, 02:57 AM

Most martian visibles clouds only hovers at high altitude. These are found around Olympus, Tharsis mountains, Alba Patera, above the Margaritifer Terra, Meridian Planum and most of South polar region: Planum Australe.

http://www.marstoday.com/news/viewsr.html?pid=20843

Rodolfo

Posted by: climber Jan 17 2008, 01:40 PM

More about clouds, shadows and clouds composition : http://www.spaceflightnow.com/news/n0801/16marsclouds/

Posted by: djellison Jan 17 2008, 02:01 PM

This all seems like ESA 'discovering' something that we already knew, again. (H2O ice at the poles for example). We've seen clouds, no astronaut on mars would be suprised by the, we saw them with MPF, MERA and MERB - not to mention from Earth ground obs, Hubble, and orbit around Mars.

Doug

Posted by: ustrax Jan 17 2008, 02:31 PM

They are not saying that they have 'discovered' anything new Doug...
“This is the first time that carbon dioxide ice clouds on Mars have been imaged and identified from above...”
or...
"“Previously, we had to rely on indirect information – for example, from the SPICAM instrument on board Mars Express - to find out what the clouds are made of. However, it is very difficult to separate the signals coming from the clouds, the atmosphere and the surface.”
or even...
"Even more surprising is the fact that the CO2 ice clouds are made of quite large particles - more than a micron (one thousandth of a millimetre) across"...how would you get this data from MPF, MERs or other present orbiters if not with OMEGA onboard MEx?...
Better read the whole http://www.esa.int/esaCP/SEM1DV3MDAF_index_0.html...

Posted by: djellison Jan 17 2008, 02:44 PM

"Until now, Mars has generally been regarded as a desert world, where a visiting astronaut would be surprised to see clouds scudding across the orange sky"

THAT - is an outright lie. You can't argue it any other way. It's utterly utterly wrong, inexcusable and totally unacceptable. They've written the press piece to make it sound like they've discovered some sort of new phenomenon - and they've have not. They've investigated a known phenomenon and found out new things about it.




Doug

Posted by: ustrax Jan 17 2008, 03:12 PM

Oh...I see...that little creative writing detail...

Posted by: tedstryk Jan 17 2008, 03:12 PM

Very true. Martian clouds, both ordinary and dust clouds, have been known since the 19th century. They have been know to be carbon dioxide (well, most of them are) since Mariner 9 and assumed to be so longer than that. Plus they were clearly photographed from the ground by Pathfinder (the Viking 6 bit lander imaging system made imaging discrete clouds with any certainty impossible). Doug is right here. This is not an error or misinterpretation. The author of the press release is either hopelessly uninformed or a liar. The scientist interviewed, unless he was seriously misquoted or there was some serious language issue, is without question a liar. Shameful, that is all I can say, shameful. The sad thing is when media pick up crap like this and swallow it hook, line, and sinker.

Edit: Yes, I looked it up. Kenneth Herr and George Pimentel published a paper in Science in 1970 reporting the direct detection of carbon dioxide clouds by the infrared spectrometers aboard Mariners 6 and 7. Not to mention Mariner 9, Viking 1 and 2, Mars-3, and Mars 5, which also detected them (possibly later spacecraft as well - I am just listing "first wave" missions. I will also add that Todd Clancy directly detected CO2 clouds from the ground using microwave data.

Posted by: tedstryk Jan 17 2008, 03:47 PM

No, it ISN'T the creative part that is the problem. The fact that there are clouds visible in the Martian sky has been known for over a century, and they have actually been seen scuttling across the sky on a routine basis by Pathfinder and the MERs. The illustration is given to help the public connect with the "discovery." The problem is that there is no new discovery, and the idea that an astronaut would see clouds is in now way revelatory. The idea that OMEGA has changed how we imagine what we would see standing on the Martian surface is at best a horrible miscommunication (although it is difficult to see how), and otherwise is simply a lie. You can defend them all they want, but it is still a lie.

Posted by: centsworth_II Jan 17 2008, 04:07 PM

Ok, guys, if this continues I'm going to have to move this discussion to the
http://www.unmannedspaceflight.com/index.php?showtopic=1777&st=195&start=195 thread.

Posted by: ngunn Jan 17 2008, 04:13 PM

Careful folks! You might put them off making any public announcements . .

Posted by: MarsIsImportant Jan 17 2008, 04:44 PM

Although the clouds are not new, the Shadows caste by them are new. And the shadows could be seen from orbit. So the story is not about clouds, but the intensity of them. They may be stretching things a bit...but calling them liars?

Remember, "Only the Shadow knows!"

Posted by: ustrax Jan 17 2008, 05:22 PM

Man...I'm not defending anyone, I hope an institution like ESA can do that for itself...sounds to me that everyone can defend them all they want...do you think that this release has come out of some sort of secret room where those evil ESArians want to fool the world trying to convince us that THEY discovered clouds on Mars?
At least I didn't get that idea...and I think who wrote the release was far from thinking that it might get this reaction...
btw...I'm with MarsIsImportant here, that's the important issue here...height, thickness, particles' size and composition, if not I must agree with centsworthII and move this posts...

Posted by: tedstryk Jan 17 2008, 05:41 PM

I never suggested an evil ESA conspiracy, nor do I make a habit of doing so. Martian cloud shadows are also nothing new. This is exciting new data, but the Mariner and Viking infrared instruments, MOLA in passive mode, Phobos-2, and plenty of other groudbased and spacebased datasets provide valuable information on this. OMEGA data is excellent and is no doubt greatly enhancing our understanding of Martian clouds. Still, the idea that it has caused some radical shift in how we perceive them is simply untrue, and I can't see this being an accident.

Posted by: djellison Jan 17 2008, 06:26 PM

That's about the full story there Ted. It's the total lack of acknowledgement of previous science, pretending that no one has studied this before. They're doing good science, that I am sure of. They're doing an utterly dreadful job of communicating that science. I would rather a press release like this didn't exist at all - as a European, and thus someone who's paid for that release to be written, it's embarrassing. Either the writer has never ever heard of google, or they are intentionally sexing it up. Both are frankly, not good enough. Plenty of scientists and engineers from the past couple of decades have worked long hours and dedicated their careers to doing Mars science - they would have every right to feel put out and somewhat insulted byt the lack of acknowledgement of their work with this announcement.

Doug

Posted by: peter59 Jan 17 2008, 08:04 PM

"Until now, Mars has generally been regarded as a desert world, where a visiting astronaut would be surprised to see clouds scudding across the orange sky. However, new results show that the arid planet possesses high-level clouds that are sufficiently dense to cast a shadow on the surface."

This is ESA's megalomany.

And surprise, martian sea of clouds 30 years ago.

Posted by: ngunn Jan 17 2008, 08:43 PM

Somebody got their facts wrong, no doubt about that. But is this really the main news? Surely that's the images themselves and what those can tell us about Martian clouds? We should maybe think about how we look too. After all we're quick enough to complain when the rest of the media focus on a problem or failure rather that the magnificent achievements of space exploration. Agreed, errors should be noted, but that can be done in a friendly way. You all have had more dealings with ESA than I have and may have good reasons that I don't know about for being more vehement, or inferring particular motives, but it makes me a bit uncomfortable I have to say.

Posted by: nprev Jan 18 2008, 12:30 AM

I think that's an accurate analysis; a mixture of both, probably. However, it should not be forgotten that it took NASA literally decades to learn how to "market" its discoveries (and don't ever think that's not necessary; recall the fact that people were calling TV stations and complaining that live moonwalk coverage was interrupting ancient reruns of I Love Lucy)--and they still have a long way to go.

ESA's trying, they just really screwed this up, and the writer of this release should be, at the very least, disciplined.

Just to be clear: I am not defending this article, nor these tactics; scientific accuracy and objectivity are of course paramount, now and forever. To me, this looks like one of the initial points on a very steep learning curve.

Posted by: tedstryk Jan 18 2008, 02:00 AM

I would agree with this on a lot of their PR. This simply goes beyond that. The repeated emphasis of first direct detection, coupled with the idea that it changes the way we perceive the Martian surface is either a work of pure idiocy or a lie. Given how much of it comes from one of the scientists, I have difficulty believing it is pure ignorance. I think it is willful.

Posted by: MarsIsImportant Jan 18 2008, 02:50 AM

Quoted directly from the second paragraph of the ESA article:

"Mars is not entirely a haven for Sun worshippers. Clouds of water ice particles do occur, for example on the flanks of the giant Martian volcanoes. "

This is before they get into the details of the story.

I hate to be put in the position of defending them, but the critics here are going too far. The ESA does acknowledge previous evidence of clouds. They have acknowledged other people's work related to the subject. What they have pointing out is that these particular clouds were found near the equator in an area where clouds of this type should not be expected. I think people have misinterpreted it as if they stated it was a unique discovery on Mars as a whole. My quote clearly shows that they did not say that.

Yet, They did not go out of their way to give specific references. When something is generally considered to be the norm in a particular field of study, specific references are generally not needed. Everybody knows that clouds have been seen on Mars many times before. That is kind of the point of not making the specific references. Perhaps they should have been more clear.

I didn't interpret the article as apparently many others did. Perhaps it did gloss over a few important points. But it certainly did not ignore them as some indicate.

Posted by: tedstryk Jan 18 2008, 03:00 AM

In reality, the criticism is not at all over the top. Equatorial clouds on Mars, but have been routinely known and photographed from the ground since the early twentieth century. For example there are images depicting them in E. C. Slipher's Photographic Survey of the Brighter Planets. Carbon Dioxide clouds, not just water ice clouds, and certainly not just topography related clouds, have been studied extensively by previous spacecraft.

Posted by: MarsIsImportant Jan 18 2008, 03:12 AM

Yes, but the point of the article was that before when these clouds were spotted, it was mostly assumed that they were CO2 clouds. The study confirms that they are CO2. It pointed out the problems with previous attempts at confirming that the clouds were CO2.

Granted, the article could have been written much better than it was. But much of the criticism is way over the top.

Posted by: tedstryk Jan 18 2008, 03:30 AM

I understand what they are trying to say. But the idea that all previous detections were indirect simply is untrue.

Posted by: ElkGroveDan Jan 18 2008, 04:00 AM

I think this brings us full circle back to the http://www.unmannedspaceflight.com/index.php?showtopic=1777thread. As we all recall Ted began it back in Nov., 2005 with a joke about their impending "major discovery announcement."

If only Ted had inserted the line "Mars has clouds" we would have smiled just the same back then, but here we are today facing that very announcement.

Good call Ted.

Posted by: n1ckdrake Jan 18 2008, 06:33 AM

The criticism over this ESA news release is entirely justified.
Ice Clouds over Mars - http://apod.nasa.gov/apod/ap971013.html
Clouds over 'Endurance' on Sol 290 - http://www.jpl.nasa.gov/missions/mer/images.cfm?id=1403

Posted by: edstrick Jan 18 2008, 08:09 AM

“This is the first time that carbon dioxide ice clouds on Mars have been imaged and identified from above...”

Viking orbiters specifically detected very high altitude clouds that occurred in a recurring patch over mid-southern latitudes at one time of year. They were sharp textured and clumpy, casting <as I recall> distinct shadows that confirmed their height, and generally appeared way different from the water ice diffuse clouds and hazes. Atmosphere temperature data <very limted remote sensing 15 micrometer channel data and occultation profiles> suggested CO2 ice temps could be reached in that area at that season and elevation.

What is new here, and is a VERY significant improvement in previous science is the ability of a near infrared imaging spectrometer to clearly image and obtain identifying spectra on such clouds. The Press Release, however is cooked-up hype to to with some impressively good, but INCREMENTAL science.

Posted by: MarsIsImportant Jan 18 2008, 09:51 AM

The article is simply not well written. Because of that, it is easily misinterpreted. That misinterpretation is not necessarily the readers fault. That goes back to the fact the article is not up to standard. That is a fair criticism. I did not want to defend the article at all because of that fact. Yet the criticisms here went far beyond that fair one.

You quote them saying CO2 clouds detected from above and IDENTIFIED. That's the problem. The article itself says that these type of clouds have been seen before. People have been giving all sorts of examples of various clouds being identified from above. So you say they lied.

But in context, it is clear to me that the writer meant 'confirmed'. There is a big but subtle difference. They were able to confirm it because of the new infrared imaging spectrometer and the large size of the particles within the cloud. They could separate the CO2 atmosphere from the CO2 ice in the clouds. Before, we couldn't be sure of that distinction; now we can. That means confirmation.

I don't remember them actually using that word 'confirmation' but that is what they meant. So the article is not well written. I wasn't trying to defend the article in of itself. It was clearly inaccurate in a number of ways. I was simply showing how criticism here has taken it a little too far in characterizing them (as in the ESA) as liars...or they are grossly ignorant. I don't think that is the case. The writer missed some of the subtleties in English and it came across as a pure 'puff piece'. That is still not excusable for a writer, but it is a far cry from calling the whole organization liars.

Edit: Another unfair criticism is that people have been giving examples where the clouds were thought to be water based clouds. That's not what the article was about. The article is talking about CO2 ice cloud detection at the equator (when they meant confirmation). It has been known for a while that CO2 ice clouds must form at NIGHT at the poles. This article points out a CO2 ice cloud at the equator during the day. Yet, people here keep giving examples of detections that claim water ice clouds, not CO2. That's not a fair criticism against the article. Yet, the article opened itself up to such criticism because it mentions previous water cloud detections near the beginning. That could also be easily misinterpreted itself. Many people have claimed in the past that these clouds were CO2, not water. This science confirms the clouds are CO2. ...I can relate to the confusion the article caused.

Posted by: djellison Jan 18 2008, 10:48 AM

It also says that an astronaut would have been surprised to see them. It infers that clouds were not known to exist.

Doug

Posted by: MarsIsImportant Jan 18 2008, 10:54 AM

I agree. The article seems to contradict itself in some spots. It was not well written. So I understand why there was so much confusion.

Posted by: Doc Jan 18 2008, 11:03 AM

This article seems to have been written by a seriously misinformed writer.
And I can't shake the feeling that ESA is trying to take all the credit for being 'martian clouds revolutionists'. Come to think of it, how can the knowledge of shadow-producing clouds be considered valuable to planetary climatology?

Posted by: tedstryk Jan 18 2008, 12:12 PM

The thing that really concerns me is the quoted material from one of the OMEGA scientists, who seems just as out of line as the writer. One can only hope he is seriously misquoted.

CO2 Clouds have been directly detected before from above. It started with Mariner 6 and 7. The supposed subtle difference doesn't exist. OMEGA has done superb work at refining our knowledge of this work, but this is not revolutionary. The measured size is well within the range accepted since the 1970s. MGS TES indicated particles <=1.5 microns.

Posted by: Aussie Jan 19 2008, 09:22 PM

Hey, lets be fair guys. We have seen lots of journalistic licence and inaccuracies in JPL site updates and the Levin 'water puddle report' was released in a highly respected publication (to the subsequent chagrin of the editors). Before pointing fingers it is useful to see what the researchers really said and read the paper. http://www.agu.org/pubs/crossref/2007/2007JE002944.shtml

Hmm, submitted on 23 May 2007 and published on 13 November 2007. But the 'extravagant' claim hit the ESA site on 16th January 2008. Looks like a rush of blood to the head by the journalists to me so perhaps we could now ease up and give the researchers the credit they deserve for some of the findings.

Posted by: centsworth_II Jan 20 2008, 06:46 AM

From the abstract: "This paper presents the first unambiguous observation of CO2 ice clouds on Mars."

Is this a lie? Have the Journal editors goofed by publishing it?

Posted by: Aussie Jan 20 2008, 10:03 AM

Yeah I am probably out of date. But the last article I saw for Mars Global Surveyor (JOURNAL OF GEOPHYSICAL RESEARCH, VOL. 112) indicated that while Mars equatorial mesospheric clouds had been detected using TES/MOC, The lack of detectable infrared radiances at MEM cloud heights precluded distinction of water versus CO2 ice. The authors also noted Mars Express observations pointing to CO2 clouds. A few Mariner 6 and 7 infrared spectrometer (IRS) limb scans showed a reflection spike attributed to CO2 clouds at around 25 km altitude with a low upper atmosphere temperature. But Viking data could not confirm the low temperatures and re-evaluation of data in the mid 90s attributed the results to either H2O ice contaminated CO2 clouds or surface CO2 ice deposits with H2O ice contamination. An ambiguous result.

The abstract noted that CO2 ice is known to appear as clouds and they are not claiming to have discovered clouds on Mars, or even to be the first to identify CO2 clouds. But the first unambiguous observation of CO2 ice clouds? Since this is the author's opinion it is quite reasonable to present it in the paper and it could well be an accurate statement.

Posted by: peter59 Jan 20 2008, 11:13 AM

Abstract (1998).
http://adsabs.harvard.edu/abs/1998GeoRL..25..489C
"We argue that the blue wave clouds imaged from the Pathfinder lander 35-100 minutes prior to sunrise on Sol 39 are evidence of such CO2 ice formation within the 60-100 km altitude region; and that the 4.3 micrometer CO2 lines of solar scattered flux, in Mariner 6 and 7 infrared limb spectra of Mars are a direct spectral identification of CO2 ice cloud formation in the dayside Mars mesosphere."

Posted by: MarsIsImportant Jan 20 2008, 03:15 PM

"...Pathfinder lander 35-100 minutes prior to sunrise on Sol 39..." does not sound like a day time observation from above. So there is a difference in the data sets. And the Mariner 6 and 7 data was specifically addressed by the paper, so we don't need to go into that again.

Posted by: tedstryk Jan 21 2008, 01:08 AM

That is such a nuanced difference, given that CO2 clouds were known, and the size measured by Mars Express was well within the upper limits. The Pathfinder data is also very relevant. The team indicates that they have found an unexpected phenomenon, not simply a phenomenon not yet observed in the day. At any rate, this discussion is becoming a moronic and a waste of time.

Posted by: ElkGroveDan Jan 21 2008, 01:58 AM

I was just thinking the same thing