More results for the possibility of Life on Mars - Page 16

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Posts: 344

Reply: 301

PostPosted: February 6, 2012 11:00 AM 

The point is, Serpens, that no matter how small the probability is of an ejected rock reaching Mars, taking into account all your factors, if the number of ejected rocks (i.e., the number of trials), is large enough, it will overwhelm that small probability.

To use an analogy, if I buy a ticket for a national lottery, my odds of winning are very low. But if I could somehow buy a ticket every week for the next hundred million years, it would be virtually certain that I would eventually win.

John Henry Dough

Posts: xxx

Reply: 302

PostPosted: February 6, 2012 11:43 AM 

Anyone remember if it was Apollo 12, that the camera was removed from,,,,,after 20 something months on the Moon..removed with large bolt cutters if memory is correct.

Camera returned to earth..sterile environment all the way,,,and a piece of the foam inside contained virus from an assembly worker who had had a bad (sneezing) cold at the time of foam installation....anyway,,the foam was examined and the cold virus in the foam was alive and well.After the almost pure vacuum of space and many months of Luna surface exposure.

This tells us something,,,I am not sure what
Perhaps,,,,Life is tough?.


Posts: 250

Reply: 303

PostPosted: February 6, 2012 1:09 PM 

John, a nice quote of one of my biologists peers says: "It is better to overestimate life then underestimate it!" Wink

John Henry Dough

Posts: xxx

Reply: 304

PostPosted: February 6, 2012 2:39 PM 

But,,,MPJ,,, we live in a water world a sea of atmospheric humidity,,,our bodily requirements is seriously limited,,,our shell is fragile,,
Living Off-world is hampered,the
only weapons we posses are thought and mobility,,,not saying this is nothing rather saying this is a lot,,,sadly I left something out,

Reality,,,,which is Want To and $$$$.
Private Enterprise to Space is being pushed in my country as an excuse to cut NASA to the bone-yard.our president is very space non-friendly.sad but true.perhaps if the MSL
lands safely we will have a moment of popularity or a new pres. might be elected.
I don't know.miracles do happen.
Good to talk to you.
Long-winded today,,,jhd

John Henry Dough

Posts: xxx

Reply: 305

PostPosted: February 6, 2012 3:30 PM 

In total honesty=====as I see it now,,,Man on Mars roughly 2050,,,,or perhaps the Chinkos can be allowed to scare the world enough to
take Space Exploration for real.
Or Not.


Posts: xxx

Reply: 306

PostPosted: February 6, 2012 8:53 PM 

JHD. Re your 302. The contamination was traced to contamination that occurred through poor practice during the investigation of the surveyor camera recovered form the moon.

Despite the scientific pauoff things such as putting a man on the moon or any kind of space exploration is ultimately a status project. Nations with excess wealth can afford status projects. Bankrupt nations cannot. The US is in severe financial trouble and currently the government spends much more than it earns. The national debt as a function of % of GDP is roughly where it stoodafter WW2, bit then again I don't think that the US has ever been out of debt since the civil war.

Europe is a basket case. China has plentiful funds and it is actually quite significant that they are prepared to spend much of this on a status project like returning man to the moon rather than lending to the US or Europe which are seen as poor long term investment risks.

John Henry Dough

Posts: xxx

Reply: 307

PostPosted: February 6, 2012 9:51 PM 

Well I guess I will give(grudgingly)you another ''correct'' for status symbol,,,,,on another subject entirely,,,names,,,,,what do people who hang out on theses forums call themselves??Hard to say what I am asking.
There exist a certain type of people,,They are
the people that belong to usually more than one group on the internet and interact socially as evidenced by these two Red and Blue Mars Forums,,,,and you-name-it dot design dot-com.

It just seems there should be a name for people like us,,who keep this crap flowing day in day out.I have no idea what it could/should be,(my keyboard is smudged on the comma or the period,not shore.which.)
Thoughts,,,you or anybody else?

armchair explorers?
data seekers? suckers? Very Happy
byte eaters?
amateur planetologists?
internet cowboys?
data-miners? hmmmm

must be some good ones out there?


Posts: 344

Reply: 308

PostPosted: February 6, 2012 11:07 PM 

Good news, bad news.


Two ancient oceans 4Byr and 3Byr ago.

Big NASA cuts coming for Mars exploration?

Kevin Author Profile Page

Posts: no

Reply: 309

PostPosted: February 7, 2012 5:21 AM 

Latest studies say Mars has been arid for Billions of years and was only wet for 5000 years. Chances of life on the surface are zilch and below the surface possible but was there enough time for anything to develop in the first place.

On another note ExoMars and the Gas Trace Orbiter are on the back burner again as NASA has had to throw the towel in due to lack of budget. ESA are now looking to the Russians to see if they want to do a joint mission. I really hope Curiosity makes it because that is going to be the last trip to Mars for a while me thinks.

Kevin Author Profile Page

Posts: no

Reply: 310

PostPosted: February 7, 2012 5:24 AM 

Oooops that was supposed to be "arid for millions of years", its this global debt crises I am too used to hearing the word Billions every 5 minutes!


Posts: xxx

Reply: 311

PostPosted: February 7, 2012 6:59 AM 

Barsoomer. Re your 301 a cumulative of the Poisson distribution would be an appropriate methodology. The key point is that the possibility of Earth ejecta reaching Mars is infitesimal while the probability of ejecta from a Mars impact reaching Earth is many orders of magnitude higher. I regret that for some reason you do not seem to be able to understand this.


Posts: xxx

Reply: 312

PostPosted: February 7, 2012 7:15 AM 

Kevin. Beware the popular press. The real paper caveats that the analysis was done on the 600 million year old Heimdal crater ejecta blanket and that sets the time bound for findings. The 600 million year drought is just a nice catchy and totally misleading headline.

Do you really think that the ESA can be funded for Mars missions, regardless of Russian interest?


Posts: 344

Reply: 313

PostPosted: February 7, 2012 11:04 AM 

Serpens. What we have are repeated independent trials. The key point is that the number of trials is enormous. I regret that for some reason you do not seem to be able to understand this.


Posts: xxx

Reply: 314

PostPosted: February 7, 2012 5:02 PM 

Barsoomer. The basic function is conditional. For an element of the event to occur the preceding event must be fulfilled. The number of events is not enormous and the probability of success has a lot of zeros after the decimal point. I do not know how many impacts, of sufficient size to eject material with a kick off velocity sufficient to reach mars orbit, earth has endured since life evolved but it will be limited. The number of trials is relevant but does not domoinate if the probability of success is miniscule in comparison.

Re your comment on venus meteorites on earth, it would be more difficult for venus ejecta to reach earth than earth ejecta to reach mars because the sun's gravitational influence is an inverse square function.


Posts: 344

Reply: 315

PostPosted: February 7, 2012 8:15 PM 

Serpens, the number of events is not the number of impacts---it is the number of rocks released by each impact, summed over all impacts.

Evidently, that number is large enough to dominate the small probability that a rock ejected from Mars will fall on Earth. In fact, for every Mars meteorite that found its way into a collection, I think it likely there were a billion more "born to blush unseen, and waste their sweetness on the desert air." Thus, we can surmise that 10^10 Mars meteorites or more have fallen on Earth.

I think it plausible that the probability of an Earth meteorite making it to Mars might be a few orders of magnitude, say 10^3, less than that of a Mars meteorite making it to Earth. (I disbelieve your claim that the number moving inward is substantially greater than the number moving outward.) That would give an estimate of at least 10^7 Earth meteorites falling on Mars.

Actually, someone has done the math more accurately than you or I:

If you disagree with the analysis in this paper, perhaps you could cite an alternative paper in which equivalent calculations are done in a way that you find acceptable.

John Henry Dough

Posts: xxx

Reply: 316

PostPosted: February 7, 2012 8:40 PM 

Good Work ,,,Barsoomer,,,
ahh,,,Europa,,what lies beneath your icy seas?


Posts: xxx

Reply: 317

PostPosted: February 7, 2012 11:27 PM 

Oh dear Barsoomer. The Journal oc Cosmology lost it's few shreds of credibility with the Hoover fiasco. There are a number of papers that investigate the possibility of ejecta from earth impacts reaching Mars. For example:

In the model described 1000 particles are taken to have achieved sufficient kick off velocity to reach the orbit of Mars. This means that the ejecta that did not achieve this velocity has been culled. It takes a big impact to generate this kick off velocity. I think the model proves my point that most ejecta moves in towards the sun?


Posts: 344

Reply: 318

PostPosted: February 8, 2012 12:11 AM 

Serpens, thanks for that interesting reference.

Let's see, out of 1000 particles in their Monte Carlo simulation, 540 either exited the Solar System or impacted Mars or Jupiter or Saturn, while 326 impacted Venus or Mercury or fell into the Sun. That looks to me like more particles ultimately moved outwards than inwards, notwithstanding the odd remark that followed. Granted more impacted inner planets than outer planets but the difference is less than a single order of magnitude.

The more interesting statistic is that 17 particles out of 1000 in fact impacted Mars. I was under the impression that you were arguing the extreme position that no meteorite from Earth has ever impacted Mars.


Posts: xxx

Reply: 319

PostPosted: February 8, 2012 12:25 AM 

Barsoomer. That was a model where the particles had all been given the extremely high kickoff velocity needed. Just how much ejecta would achieve that is a question. For Mars ejecta that kick off velocity is so much less.

To put it in perspective. It took a massive rocket to launch the apollo payload to the moon. It took the piddling little lunar lander rocket to return the lander to lunar orbit and a somewhat minor burn to have the command module achieve lunar escape velocity and start the infall to Earth, constantly accelerating once it passed the Earth Moon gravitational boundary. The same with ejecta. Lots of initial energy to keep it moving outwards in the gravitational well, but inwards is easy.

Kevin Author Profile Page

Posts: no

Reply: 320

PostPosted: February 8, 2012 4:55 AM 

#312 Serpens yes it can fund it but to what degree is the question and over 200 million Euro has already been spent but help is required to build experiments and launch TGO and then ExoMars. That last bit is scary given Russia's recent failures let alone the landing! The deal is to share the science.

We have AstroFest here in London this weekend so I shall meet with some of the UCL guys that will have worked on this paper and shall discuss! UCL had instruments onboard and full on access to the data.

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