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The article correctly emphasizes the hazard (from collisions) to orbiting spacecraft, and (correctly) says very little about the radiation hazard to us on the ground.

These NaK particles definitely pose a collision risk to spacecraft due to the number of particles, their size and their altitude.

Number: According to the article there are a large number of NaK particles, which are "estimated to be 110,000 to over 115,000 in number".

Size: The largest particles, which are between "roughly 2 inches to 3 inches (5 to 7 centimeters)" in diameter, could really cause damage if they collide with spacecraft. Although the biggest hazard are from smaller particles (less than 1 mm diameter) since they are not tracked by ground radar. The objects that are tracked include relatively large (>10 cm) objects maintained in the US Space Command catalogue and intermediate sized (1 mm to 10 cm) that are sampled by ground telescopes and high-frequency ground radars. (See NASA JSC for more info.) Spacecraft can be manoeuvred out of the path of tracked objects if necessary.

Altitude: The particles orbit at altitudes "between roughly 530 miles (850 kilometer) and 620 miles (1,000 kilometer) altitude". ISS is at an altitude of 400 km for comparison. Most satellites in low earth orbits use altitudes between 700 and 1300 km.

Visit LDEF to see pictures of the results of some meteoroid and orbital debris impacts.

- charboy

The article correctly emphasizes the hazard (from collisions) to orbiting spacecraft, and (correctly) says very little about the radiation hazard to us on the ground.

These NaK particles definitely pose a collision risk to spacecraft due to the number of particles, their size and their altitude.

Number: According to the article there are a large number of NaK particles, which are "estimated to be 110,000 to over 115,000 in number".

Size: The largest particles, which are between "roughly 2 inches to 3 inches (5 to 7 centimeters)" in diameter, could really cause damage if they collide with spacecraft. Although the biggest hazard are from smaller particles (less than 1 mm diameter) since they are not tracked by ground radar. The objects that are tracked include relatively large (>10 cm) objects maintained in the US Space Command catalogue and intermediate sized (1 mm to 10 cm) that are sampled by ground telescopes and high-frequency ground radars. (See NASA JSC for more info.) Spacecraft can be manoeuvred out of the path of tracked objects if necessary.

Altitude: The particles orbit at altitudes "between roughly 530 miles (850 kilometer) and 620 miles (1,000 kilometer) altitude". ISS is at an altitude of 400 km for comparison. Most satellites in low earth orbits use altitudes between 700 and 1300 km.

Visit LDEF to see pictures of the results of some meteoroid and orbital debris impacts.

- charboy

Despite this being /. I decided to perform a bit of research, so here are a few links to pages that I think support my point, that terraforming as far as a more hospitable atmosphere on Mars is possible:

• http://quest.arc.nasa.gov/mars/background/terra2.h tml
• http://ganymede.nmsu.edu/tharriso/ast301/class23.h tml
• http://spacescience.com/headlines/y2000/ast22jun_2 .htm?list
• http://www.users.globalnet.co.uk/~mfogg/zubrin.htm

They may be wrong, I may be wrong, but simply claiming the fact that the current Martian atmosphere is very thin as proof that no sustainable atmosphere is possible on Mars, that does not cut it. I will grant you that a 99% earth-like biosphere is unlikely, but a lot less is needed for it to be of use to a colony. Even a slight increase in temperature and pressure would make it easier to live on Mars, some plants might be able to grow (genetically modified mountain plants), the domes (or whatever it might be) needed for habitation might have to handle a smaller difference in pressure, or the time an astronaut might survive in an accident might increase.

And besides, even if it only lasts a few thousand years, an atmosphere might still prove useful. Not that I think we should do something like this without considering the consequenses, but once we have the technology, the trade-offs and risks might prove to be small enough for us to attempt terraforming Mars.

Which means we only have to wait until December '04.

NASA planning a probe to go and study europa but this list doesn't seem to mention it.

I couldn't RTFA (/.ed) but JIMO includes a study of Europa. Europa lander/driller/submarine missions such as this are in the early conceptual stages.

would be cool for mars to attempt a venus rover despite the obvious challenges

Such as Mars not having intelligent life, much less space technology? :-)

Upfront: I am against manned space flight at the current state of the art.

Cost. Manned space missions are an order of magnitude more expensive than unmanned missions. This means that for the price of (God forbid) a manned space mission to Mars, ten or so smaller missions such as stated in the article could have been performed.

Effectiveness. Manned space missions are not as effective as often thought. The extra weight that the Space Shuttle has to carry just to accommodate the astronauts in space already consumes a significant part of its available payload capacity. This is at cost of available room for experimental equipment. Most experiments can be designed such that they can be done by robots.

Danger. Why risk lives?

I know that GWB in his Great Vision would like to see the flag of the U.S.A. proudly wave on Mars. This would cost billions of dollars - if it is possible at all (for starters, two years of accumulated radiation would surely kill the astronauts). And the main reason would be prestige, just like it was for the moon missions, as NASA admits:

"the most persistent justification for the moon race was the matter of prestige" .

NASA's budget is crippled by the costs of the manned space station ISS - which are between 60 and 100 billion dollars. Enough is enough!

...here.
So why isn't there a bit more excitement in this 'brave new age of space exploration' and why won't people use this excitement in JPL, NASA et al. to start their working day a bit earlier, say 5:00 am ?

The security guard that left the light on at least keeps up with the pace.

Fools!

My fusion reactor has been running quite a long time now.

I've even licensed it under the GPL*!

*General Power License

It can just as well be said that the X-43A did not achieve "scramjet powered flight" as the scramjet engine was only operated for about 10 seconds out of the total flight time of several minutes. I'm not an aeronautical engineer, but it seems that NASA just used a different technique to get the aircraft to the speed at which it could ignite the scramjet engine.

A lot of people seem to be forgetting that as of the mid-1970s we knew there was once liquid water on Mars thanks to pictures beamed back by the Viking probes. These images very clearly show channels and streamlined features that would have only been created by liquid water moving on the surface of Mars. (There was also more ambiguous evidence of flowing groundwater, but that doesn't detract from the strength of evidence for other observed features being created by moving surface water.)

The interesting questions were how long the water had water existed on the surface (was the flooding episodic, or was mars generally damp for a long time), when did the climate cease to be able to support widespread liquid water, where did the water go, and was there ever life?

The current probes confirm our earlier analysis: there was once liquid water on the surface of Mars, but this is scarcely news. (It would have been much more surprising if they showed water didn't once exist on Mars.) The probes presently exploring Mars have, however, gone much further than simply confirming the presence of liquid water in the Martian past; they have shown that the water that once flowed there wasn't just temporarily liberated by catastrophic events like meteorite impacts, but had to have remained liquid on the surface for quite some time. Standing bodies of water formed the intruiging geologic formations observed by the Opportunity rover, and have important implications for understanding the ancient Martian climate...in addition to increasing the likelihood that life could have once thrived there.

So if scientists are speaking up more about the possibility that Mars might have harbored, or might still harbor, life, it's probably because we're slowly accumulating a more interesting body of evidence. I don't perceive any big coverup, just many new discoveries.

As for detecting methane in the atmosphere, we've probably never previously detected it because the instrumentation with the resolution needed to detect it hasn't previously been flown to Mars, and it's difficult (but clearly not impossible) to make similar measurements from Earth. The tone of the article suggests that people have been trying to detect methane before this, but have only recently succeeded, which isn't too surprising given the thing that we were trying to detect exists at only about 10.5 parts per billion.

The US has tried to be careful about sterilizing its Mars landers. The Viking landers were very thoroughly sterilized, since their main purpose was to look for signs of life; it was important to eliminate false positive results from terrestrial "hitchhikers". The Pathfinder and MER landers were mainly geology missions and that, combined with the negative Viking results, led to a somewhat lower standard of sterility. (IIRC they went over the exterior of the rover with disinfectants, but did not have to heat sterilize all the internal components.) According to this interview:

http://www.ksc.nasa.gov/nasadirect/elv/merb/theis- ab.htm

"There is a set of international treaties and agreements that regulate the ability of us to take bacteria or organic material or spores to Mars in order to avoid contaminating Mars for future scientific investigations. The Mars Exploration Rover project is what is called a Class B. We're not involved in the search for life and so we have a level of cleanliness that we did when we put the rovers together. If you were a Class A mission looking more directly for life, the requirements would be much more stringent. You would actually have to sterilize the equipment, almost like an operating room, in order to be able to satisfy these agreements."

I'm curious about the extent to which the Soviet Mars landers were sterilized. None of them were exactly successful, but a couple made it to the surface and crashed there.

You overlooked this vision with $1B funding increase over 5 years with a complete reorganization of NASA (and $) toward this vision.

Our President "actually proposed spending government money on [this vision] during his term" along with hundreds of other initiatives. Iraq may be important but perhaps we're too focused on it (a tree - a big one, granted) and missing the forest.

As more and more data is showing, it appears Mars once had a much denser atmosphere that probably supported liquid water. There is also evidence that Mars once had an Earth-like dipole magnetic field and magnetosphere which protected the ancient Martian atmosphere from the radiation of the solar winds. Many researches now believe that without a magnetic field the Martian atmosphere was simply eroded away by the solar wind.

I am merely a layman on this subject, but it seems to me that without somehow restarting the Martian dynamo to generate a global magnetic field, the idea of terraforming Mars will always remain science fiction.

With this information, it seems to me that the idea of terraforming Mars is a joke. Am I missing something?

References:
http://science.nasa.gov/headlines/y2001/ast31jan_1 .htm
http://www.pbs.org/wgbh/nova/transcripts/3016_magn etic.html
http://spaceflightnow.com/news/n0012/17marsmagnet/

Perhaps broadband would reduce the need for so much automobile traffic and congestion. With information at your fingertips, many could reduce trips to library, to buy newspapers/magazines, comparative shop online and even telecommute, etc. After telecommuting 1 day/week via broadband on a pilot program for several years, I feel in my case it's a real productivity boon, but perhaps not for all (i.e. new hires) but a privilidge earned over time or as an achievement award..

I think the X-43 is 12-feet-long. This quote:

"The unpiloted 12-foot-long vehicle, part aircraft and part spacecraft, will be dropped from a B-52,aircraft. It will be boosted to nearly 100,000 feet by a rocket..."

from this NASA page is one source.

I think you are underestimating the size of the Pegasus rocket and B-52 bomber. I know I did. A quick google search found a page on the Pegasus rocket: it is 55.4 feet long and about 4 feet in diameter.

He added: "It's difficult to imagine that primordial methane [from geological activity] would continue outgassing for four billion years [the age of Mars]. This looks very intriguing."

Unless they're leaving something out about the fuel they're burning with the hyper-compressed air, this engine would be ultra clean too. Since the fuel is hydrogen (as shown by this NASA diagram), and the combustion agent is the oxygen in the compressed air, then the byproduct would simply be water. There would of course be some heat pollution, which is still actually a potentially serious pollutant, but only when the contrails created from such heat become as numerous as those from today's airliners.

basically the higher you go, the less air there is, and the slower sound travels. So, the mach number, which is the ratio of your speed to the speed of sound, will be higher at high altitudes if the speed is constant.

If you check out this you'll see that at 100,000 feet the speed of sound is 684mph.

The X-15 engine was an XLR-99 single chamber rocket. It produced 60,000 pounds of thrust and it burned 18,000 pounds of liquid oxygen and anhydrous ammonia in 85 seconds. The propellants were fed by a steam driven turbopump; the source of the steam was hydrogen peroxide decomposed by passing through a silver screen catalyst bed.

Nasa has a lot of interesting pictures of the X-43A posted.

Because it's a stupid idea. A 1-km asteroid weighs a few trillion kg. If you get your rocket data from NASA rather than Niven, you can run numbers on your idea instead of saying 'it's simple' out of your ass. If a VASIMR drive can hypothetically get 20 tonnes to Mars in 40 days, how long does it take to move 10^9 tonnes? Think about it. (Put a few dozen engines up there, be creative. Be optimistic about the delta-V required. Any luck moving that rock in less than a century?)

And please think again about why you're doing it. Why exactly is an asteroid at L4 "a great place to harvest solar power"? (it's not.) What sort of astronomical observatories are you putting there, and why is it better to have a big rocky base than a free-flyer? And, of course, why are "the costs ... very small"??

I'm sorry, I don't want to pick on your post in particular, but there are several posts saying similar things. Any space scheme is practicable when you pull enough technology/economics/orbital mechanics out of your ass. In the real world, EVEN WITH A SPACE ELEVATOR, interplanetary space is distant, hostile, and generally cost-ineffective.

I'm very proud of the things that humans can accomplish in space and on Earth. I hate to see half-baked schemes like yours floated, since I feel like you're 'disappointed' that we don't follow through. Dammit, let's be proud of real ideas like Con-X and LISA (and fund them, Mr. Bush!) instead of moaning about or failure build Mars bases and warp drives.

Because it's a stupid idea. A 1-km asteroid weighs a few trillion kg. If you get your rocket data from NASA rather than Niven, you can run numbers on your idea instead of saying 'it's simple' out of your ass. If a VASIMR drive can hypothetically get 20 tonnes to Mars in 40 days, how long does it take to move 10^9 tonnes? Think about it. (Put a few dozen engines up there, be creative. Be optimistic about the delta-V required. Any luck moving that rock in less than a century?)

And please think again about why you're doing it. Why exactly is an asteroid at L4 "a great place to harvest solar power"? (it's not.) What sort of astronomical observatories are you putting there, and why is it better to have a big rocky base than a free-flyer? And, of course, why are "the costs ... very small"??

I'm sorry, I don't want to pick on your post in particular, but there are several posts saying similar things. Any space scheme is practicable when you pull enough technology/economics/orbital mechanics out of your ass. In the real world, EVEN WITH A SPACE ELEVATOR, interplanetary space is distant, hostile, and generally cost-ineffective.

I'm very proud of the things that humans can accomplish in space and on Earth. I hate to see half-baked schemes like yours floated, since I feel like you're 'disappointed' that we don't follow through. Dammit, let's be proud of real ideas like Con-X and LISA (and fund them, Mr. Bush!) instead of moaning about or failure build Mars bases and warp drives.

The simulator link is incorrect. It points to 2004 YN1. The correct link. For a good view in the simulator, tilt the 3D view to straight down, center on earth and zoom in all the way.

New Scientist has an interesting article in their latest issue.

For a more technical explanation, read the paper presented at the Lunary Planetary Science Conference last week.

Did you try the 250m pixel size link[4.5M image] from the same page?
Incredible resolution!

I was looking at the orbits of Pluto and Neptune on the applet, and noticed that Pluto is shown as inside Neptunes orbit at present and until 2011, but I was under the impression that Pluto was once again the farthest planet, as of 1999, and wouldn't pass in again until 2226. So I'm not sure their orbits are correct....

Who know the /. effect could rip space-time?

It will be the first time I ever saw this.

...which does seem pretty camel-through-eye-of-needle at ranges of tens of millions of km. Venus gets two flybys @3000km and 300km.

This is needed because Earth orbit is about 3x as energetic as Mercury orbit. Messenger needs to dump the other 2/3 of its momentum, and slingshot flybys are far and away the cheapest method for that. This requires eveything to be lined up just so.

It's a pity, really, because I suspect Mercury of harbouring numerous hermeological surprises (as surprising as Valles Marineris on Mars, a 3000km gouge up to 10km deep which was not formed by water, wind or tectonics), and a bugger-the-cost lets-burn-many-tonnes-of-propellant (much to meet Mercury, a little more to kick the probe into orbit around it) approach would get a probe there in only a few months.

We don't have many pictures of it yet, and the aforementioned surprises should stimulate significant scientific progress, most likely by killing off a large percentage of current solar system formation theories.

At least there will still be a probe. With Dubya at the reins, it could have been worse.

...which does seem pretty camel-through-eye-of-needle at ranges of tens of millions of km. Venus gets two flybys @3000km and 300km.

This is needed because Earth orbit is about 3x as energetic as Mercury orbit. Messenger needs to dump the other 2/3 of its momentum, and slingshot flybys are far and away the cheapest method for that. This requires eveything to be lined up just so.

It's a pity, really, because I suspect Mercury of harbouring numerous hermeological surprises (as surprising as Valles Marineris on Mars, a 3000km gouge up to 10km deep which was not formed by water, wind or tectonics), and a bugger-the-cost lets-burn-many-tonnes-of-propellant (much to meet Mercury, a little more to kick the probe into orbit around it) approach would get a probe there in only a few months.

We don't have many pictures of it yet, and the aforementioned surprises should stimulate significant scientific progress, most likely by killing off a large percentage of current solar system formation theories.

At least there will still be a probe. With Dubya at the reins, it could have been worse.

...which does seem pretty camel-through-eye-of-needle at ranges of tens of millions of km. Venus gets two flybys @3000km and 300km.

This is needed because Earth orbit is about 3x as energetic as Mercury orbit. Messenger needs to dump the other 2/3 of its momentum, and slingshot flybys are far and away the cheapest method for that. This requires eveything to be lined up just so.

It's a pity, really, because I suspect Mercury of harbouring numerous hermeological surprises (as surprising as Valles Marineris on Mars, a 3000km gouge up to 10km deep which was not formed by water, wind or tectonics), and a bugger-the-cost lets-burn-many-tonnes-of-propellant (much to meet Mercury, a little more to kick the probe into orbit around it) approach would get a probe there in only a few months.

We don't have many pictures of it yet, and the aforementioned surprises should stimulate significant scientific progress, most likely by killing off a large percentage of current solar system formation theories.

At least there will still be a probe. With Dubya at the reins, it could have been worse.

Here's a nicer image of the cyclone.

Here's a picture of the old B-52B (foreground) and their new B-52H (background) from the "50th Anniversary of the B-52" event a couple years ago. I personally like the old-fashioned 1950's "Right Stuff" look of the older one more than the hospital-white new one.

Wow. Lot's more NASA B-52 pics

Here's a picture of the old B-52B (foreground) and their new B-52H (background) from the "50th Anniversary of the B-52" event a couple years ago. I personally like the old-fashioned 1950's "Right Stuff" look of the older one more than the hospital-white new one.

Wow. Lot's more NASA B-52 pics

The unofficial manned air speed record is Mach 6.7 which was attained by the X-15 according to this X-15 fact sheet.

Slight off-topic, but why do I have to go to Jet Propulsion Laboratory to find out about the Mars rovers, and then I have to go to National Aeronautics and Space Administration to find out about fancy new jet engines?!

Is it a cunning plan to out-fox those secret stealing ruskies?

Slight off-topic, but why do I have to go to Jet Propulsion Laboratory to find out about the Mars rovers, and then I have to go to National Aeronautics and Space Administration to find out about fancy new jet engines?!

Is it a cunning plan to out-fox those secret stealing ruskies?

From that, I got 5.868 billion for Human Space Flight out of 15.690 billion budget for 2004. I checked this some months ago, and it took a bit of finding again. I remembered "5 billion and something out of 15 billion and something" for next year, which is why I called it "Roughly" above.

Your figures are obviously later than mine (and they break down into more detail - thanks for the link). I note that the 2004/05 estimates for the Space Station are up from 1.2 billion to 1.7, the Shuttle is up from 3.301 to 3.968. Total Human Space Flight (including Ops Support, Payload and ELV support is up to 6.1 billion.

You can add in X-37, OSP, PAD and DART, for an extra 550 million, taking Manned Space Flight Ops and research to 6.65 billion out of 15.469 billion. Not really a majority of their resources - the 7.7 billion figure that you mention includes general (unmanned) launcher research and engineering and Robot systems research (which you really can't put down against the Manned Space Flight side of the ledger :-). )

Solar Systems exploration weighs in at 1.3 billion, Mars Exploration at 570 million, Astronomy at 877 million. Including other Space Science programmes, Space Science is just over 4 billion. Earth Science is at 1.5 billion, Biological and Physical research at a hair under 1 billion, Aeronautics also at a shade under 1 billion. Total Science expenditure is totalled as 7.66 billion.

You could well argue that manned flight gets more than unmanned flight - it does cost more. There's more to the science than the launcher and probe costs, though, and the largest chunk of NASAs budget goes to science.

You don't have to guess at my meaning for Quote: Not to mention that the program of Lunar Base plus Manned Mars program will be unlikely to be anywhere near one thousand times the price of Spirit and Opportunity, and I didn't mean that it would be a lot more. The bit in my post breaking down the trillion dollar claim (which is far better done at The Space Reviewbreaks it down far better. The estimated price in using the 1989 price (inflation adjusted for 2004 dollars) for a Mars mission is $276 billion (including development of a new manned launcher of noticeably greater capacity than the Saturn V). Using ISRU techniques and lesser launchers, and benefiting from improvements in the launcher field, this figure could be drastically reduced. The moon missions and Lunar Base (including operating costs and support over 20 years) should also be far less than the (inflation adjusted) $336 billion for the gold plated solution of the SEI).

So your contention that "It can't possibly be less [than 1000 times the price of Spirit and Opportunity, i.e. $820 billion]" puzzles me. If the gold-plated solution for everything comes in at about $500 billion (over 30 years), and we're planning on using more intelligent, far cheaper approaches, why do you feel that this cheaper solution has to be more than $820 billion?

Untrue. Roughly one third of NASAs budget (5 billion of 15 billion) is devoted to manned space flight.

Untrue. In 2004, NASA claimed expenses of 7.7 billion for manned spaceflight. And of the remainder, some of it (1.5 billion+) is research for more manned spaceflight. And some money goes to non-spaceflight activities.

So manned flight not only takes the a majority of their resources, but more pertinently, it gets much much more than unmanned flight.

Not to mention that the program of Lunar Base plus Manned Mars program will be unlikely to be anywhere near one thousand times the price of Spirit and Opportunity.

It can't possibly be less, so I guess you're saying it'll be a lot more. Could be.

I'm going to reorder this a bit in the reply.

robots don't [do these things]:

sleep: false. The Mars Exploration Rovers shutdown each night. Go read the MER website. Each day, they have wake up music that they play when they get the rovers going again.

age: false. The MERs (and other probes) degrade once at Mars at rates far faster than people do. The MERs were expected to last 90 days, but may last longer. Additionally, if the probes don't "age" then where are Viking 1, Viking 2, and Pathfinder?

necessarily have to invest many unproductive months in a return trip to Earth: they do if you want a sample return! Otherwise mostly true. There are plenty of people that are willing to go one way. I'm sure that you could recruit right here on /. if you provided a net connection and didn't mind the whining: "I'm last post again!"

require air or water or food: This is true. However, a person requires ~5 kg of food, water, O2, etc. per day. IIRC, it's something on the order of $100k/lbs to Mars (assuming that the EELV isn't less expensive than the Shuttle per pound). That means $1.1 million per day per person. With 10 people, that puts it at $11 million per day. With a mission time of 2 1/2 years, that gives us $10 billion. Assuming we get economies of scale out of this at all, it will be much less. It's also a trivial fraction of your $900 billion.

miss their families (or vice versa): this is completely true. However, betcha there are still people willing to make the trip.

suffer from nervous breakdowns: could have sworn Spirit had something not unlike this. ;)

become crippled from years of low-G: Do believe that galileo, the probe, had a mild problem here too with its antenna. Generally though, you are more correct than not.

inspire public outcry when they are casually abandoned in deep space after a particuarly nasty technical glitch: personally, I think this is more the media declaring something an outcry than really is. The people that do make the outcry then are often the people that bemoan the spending in the first place. Note, the families of the Columbia astronauts are fully supportive of going forward with more missions, iirc.

Now, pay close attention to the difference between $820 million and $900 billion. That's the difference between the (known) cost of two unmanned Mars missions and the (estimated) cost of Bush's manned one. It implies that, to get a better "ROI" from manned flight, your Young Pioneers with their rock hammers and their can-do attitudes will have to be one thousand times more productive than robots,

Let's assume that $900 billion is an accurate measurement of the cost and break it down.

Generally, the Mars mission profiles have had about 10 people on them. That means, per person, we're down to $90 billion each. Still 200 times the cost of one of the MERs.

IIRC, the number of days on Mars for the astronauts is about a Martian year (687 earth days or 670 martian sols). That gives us a per day cost of productive $134 million per person. The MERs projected cost per day is $5 million if it were to only last 90 days or half that if they last 180. That means that an astronaut would be 27-54 times as costly. That means that they would have to be that much more productive, ja?

Now that brings us to productivity. An astronaut would be able to do what the MERs have done in 80 days in at most a single day ! Go back and read EXACTLY what the MERS have done. Read exactly how far they've traveled. For robots, its an extremely impressive accomplishment. For a human being, I'd have his or her ass canned if that's all they'd done in a day! Good field geologists are enormously productive and on Mars they'd have easily collected said rocks, examined them in the same

What, you mean like this?

I'm all for a mission to Mars. First, build a Space Elevator, then....

Yer what??

"Flamebait is a message posted to an Internet discussion group, such as a newsgroup or a mailing list, with the intent of provoking an angry response (a "flame")." - http://en.wikipedia.org/wiki/Flamebait

I'll admit that I can barely restrain myself from posting an angry response, but not to the post, which is well thought out and informative, and properly backed up with links to a serious article, and a relevant image.

..First I should note that if microbes exist then they should leave a trail... And that trail may be as big as to be visible from above: Life on Mars: Giant Fossils http://www.resa.net/nasa/mars_life_gifossil.htm

This isn't even slightly contentious. Bacteria do exist in huge colonies. Their secretions or their dead bodies can build up into huge structures, in much the same way that small creatures produce coral reefs. Huge fossil bacterial mounds are so common that there is a name for them, stromatolites. They can be seen from above, often from a great height. Anyone following the link would have discovered this. If Mars has followed a similar evolutionary path, stromatolites should be even more visible there than on Earth, because there has been little recent biological activity there that might cover them up or recycle them into something else like there has been on Earth.

Second there's the chemistry of rocks. The more deep we study them, the better we get into their evolution. In some cases the "phases" or "cycles" of processes around certain minerals can be done only with the help of microorganisms.

Again a perfectly valid point, in an informative post by a person who seems to have a good professional grasp of his subject.

..

http://cydonia.ksu.ru/parafossil/parafossilA.png

Is that a fossil? Well that thing has many things that point to organics. ...

and the writer goes on to point out those things. But he admits the object could be a tiny lump of stone that just happens to be nearly symmetrical, and just happens to have the other characteristics mentioned. On its own it is not conclusive.

But the worst this something has is the fact that is laying there lonely and unique. ..So until someone gets a better enhancement of that (there are six frames of that rock) or we find something similar, it will remain something.

But compare it e.g. to the dark object on the right hand side in http://marsrovers.jpl.nasa.gov/gallery/press/oppor tunity/20040323a/Dells_C-B058R1_br.jpg

- and spot the similarities. Two specimens of the same fossil species? It's hard to be sure because the parafossilA.png object is well eroded, but there's a definite similarity in shape. And there is a very large number of other fossil candidates in the Nasa images. Nothing is laying there "lonely and unique".

The planet is quite dead and you don't need microscopes to be sure of that.

Now I would say that really is contentious. But it's hardly flamebait in the context of this site, because it agrees with the scientific consensus.

I already commented on this over here but hey...

I'm a space nut so you can guess where I'm going with this.

Aerogel is a really cool substance. It's glass foam that's very very light and it's an excellent insulator. I don't know about it's radiation blocking properties though.

If this carbon foam is of comparable weight as aerogel (negligible), it's perfect for space use. The lighter the better since it costs $thousands/kilo to get stuff off the ground. If it blocks radiation, fantastic. Water and metal are the big rad blockers now but they're heavy. If it can act as a good insulator too, you're golden. If not, a sandwich of aerogel and carbon nanofoam could act as a heat trapper so you don't freeze and a radiation blocker so you don't get zapped. And all for practicaly no weight. Shazam!

http://antwrp.gsfc.nasa.gov/apod/astropix.html

What could be better than a page where you learn a little tidbit about the universe every day and usually see a new pretty picture?

The Astronomy Picture of the Day has been my default Home Page since I started checking it in 1995.

I used to feel the same way; my home page was about:blank for years. Now my home page is Astronomy Picture of the Day. I'm interested in astronomy and this page is different every day. That makes it a double bonus: I don't get bored with my home page, and I want to visit APOD anyway -- this way I don't forget.

Short answer, temperature. It's way, way, way too warm for any liquid like N2 or methane or ammonia to form as a liquid. And it's always been too warm. So the probability that the rock formations occured from any of those liquids is precisely zero.

Secondly, H2O2 is highly unstable, it quickly decomposes into plain-old H2O and O2 in sunlight and/or temperatures above freezing. Both conditions exist and have existed on Mars for billions of years so there is zero probability that H2O2 had anything to do with it.

2. How much, if any, of the present evidence could be explained by flows of liquid CO2, nitrogen, methane, ammonia, or some other liquid?

Zero evidences for all of those substances. Again, its far, far, far too warm. First, carbon dioxide does not exist in liquid form at atmospheric pressure at any temperature. It requires a temperature of 20 degress Celsius and a pressure of 30 atmospheres to form. Mars has never had such conditions so there is again, zero chance liquid CO2 had anything to do with Mars' sedimentary rocks.

The other compounds on your list require extremely cold temperatures to form into liquids. Far, far colder than it EVER gets on Mars for most of them. It also requires a much higher atmospheric pressure than Mars had for most it's existence. Finally, there isn't sufficient quantities of some of these compounds to form rivers, lakes or oceans, nor is there any evidence of that there ever was enough.
Here's the list of temperatures:

• Nitrogen == -196 degrees Celsius @ 1 atmosphere of pressure
• Methane == -162 degrees Celsius @ 1 atmosphere of pressure
• Ammonia == -33 degrees Celsius @ 1 atmosphere of pressure
  It gets cold enough on Mars for this, but there is very, very little amounts of it.

Which evidence, if any, points most strongly to the presence of large amounts of H2O as the liquid in question? I know there are currently thought to be large, polar caps of solid H2O, but how much of the current evidence precludes the existence of large seas of some other liquid in the distant geological past?

A great source of new information about our universe and also a great source of potential desktop pictures.
http://antwrp.gsfc.nasa.gov/apod/astropix.html

>>The engineers don't assemble the shuttle in space, so that shouldn't be an issue.

But during maintenance, the Orbiter, isn't always in a dorsal-up position during maintenance. As illustrated here.

There is no up.

wbs.

Modern journalists are talking about the fossil crinoid stem. If some more of these turn up, it will be pretty exciting!

Dunno. Yes, the heatshield is much farther away (it is barely visible in the pan to which you refer, at about 120 degrees, as a blotch on the horizon). Maybe something was flung off during the bouncing, or maybe it is some other, smaller part that is shed during the landing sequence?

Alternatively, maybe it is a piece of light-coloured bedrock flung out of either "Eagle Crater" (the one Opportunity just drove out of) or the big one in the horizon in the distance, as ejecta. That can travel a long way. It would tend to stay put and stick out as wind stripped away the surrounding sediments. Regardless, I'll bet it will probably be a weighpoint on the traverse towards the big crater, and we will know more about it soon enough.

Ah, I checked one of the earlier panoramas in that direction, taken while Opportunity was still in the Eagle crater, but high enough on the rim to peek over the edge:

pan of Opportunity horizon

This one is in color, and the caption identifies that feature as a rock. It looks plausible. The caption says: "This rock is about 40 centimeters (16 inches) across and 50 meters (164 feet) from the rover's position." It is closer than that now, judging by the change in perspective between this image and the new one.