Rosetta, Philae and Comet 67P/Churyumov-Gerasimenko.

[peadar1987]

You say its implausible for life to exist on a comet?

The world was once thought to be flat. They say the water, and life, came to Earth via the comets.

NOTHING is impossible... just some things may be improbable.

They said there was no water on the Moon, apparently, given the last test, there is.

Maybe there is life on the comet. What I'm fairly convinced of is that this "unequivocal evidence" that one utter charlatan crackpot of a "scientist" has found is nothing of the sort.

[vger]

Something I'd be interested to know is: what instruments could unambiguously detect life on a comet?

If you're talking about Star Trek style scanners, you're out of luck. And we've been to nowhere near enough places to have a clue of just how diverse life might be, and whether or not the very building blocks of it could be radically different on other worlds. All we can do now is look for signs of what brought us into being, because life on Earth is currently the only template we have.

But if you wanted a smoking gun, I think the first probe to ever do it was Viking. You take a soil sample, put it into an airtight container with some atmosphere, and then test for changes in its composition. That will tell you with a good amount of certainty if there's any kind of organic synthesis going on (such as breathing). But even then, you've got to repeat that experiment many times before anyone will believe it, because a lot of bad things can happen to a probe before it gets where it needs to in order to conduct those tests. The Viking tests yielded positive results for the presence of microorganisms. The trouble is, some of the tests yielded positive results even AFTER the chamber had been baked to an insanely high temperature that should've been enough to kill anything. So either the test was flawed, or Mars has critters with better heat resistance than anything on Earth.

Edited July 7, 2015 by vger

[Scotius]

That would have to be one incredibly tough kind of life. Imagine it: years of drifting through interplanetary cold, while being blasted by cosmic radiation. Then months being slowly boiled away by the Sun (and being blasted by all kinds of solar radiation). Finding a lifeform able to survive such cycle would be a miracle.

[vger]

That would have to be one incredibly tough kind of life. Imagine it: years of drifting through interplanetary cold, while being blasted by cosmic radiation. Then months being slowly boiled away by the Sun (and being blasted by all kinds of solar radiation). Finding a lifeform able to survive such cycle would be a miracle.

A bigger concern for me isn't whether or not something could withstand the elements. But the amount of ambient energy available on a comet is so ridiculously inconsistent. Near the sun, you have tons of energy. But then you can go hundreds or thousands of years with practically none. That would mean one heck of a hibernation period.

But then, panspermia is a rather popular hypothesis. If life got here via a rogue object of some kind, it would've had to have been capable of dealing with these problems.

Edited July 8, 2015 by vger

[Shpaget]

Sounds like a picnic for tardigrades, the second most awesome species on Earth.

[Camacha]

That would have to be one incredibly tough kind of life. Imagine it: years of drifting through interplanetary cold, while being blasted by cosmic radiation. Then months being slowly boiled away by the Sun (and being blasted by all kinds of solar radiation). Finding a lifeform able to survive such cycle would be a miracle.

We know life that is capable of dealing with the most unlikely of circumstances and that was life that developed under the protection of the atmosphere and magnetosphere. The comet itself might provide protection too, is something is covered, the circumstances might be a lot less hostile already.

We keep being amazed where life pops up on Earth, so I am hesitant to claim circumstances are too extreme for an unknown type of life to exist. I am not even talking about wildly different types of life that might or might not be out there.

[KerbMav]

We keep being amazed where life pops up on Earth,

a planet that harbored life for billions of years.

Once in its history there were the right conditions for life to start, it then adapted to different niches to dwell in (= was subject to mutations that changed its abilities to survive in different environments) and so we find it practically everywhere we look for it.

Not saying that life could never come into existence anywhere else, but I somehow doubt that a comet is the right environment for this to happen.

The Star Trek fan in me on the other hand keeps musing which different forms Life would be able to take - different from our DNA squishy wet cellular based, I mean.

[Camacha]

a planet that harbored life for billions of years.

Once in its history there were the right conditions for life to start, it then adapted to different niches to dwell in (= was subject to mutations that changed its abilities to survive in different environments) and so we find it practically everywhere we look for it.

Not saying that life could never come into existence anywhere else, but I somehow doubt that a comet is the right environment for this to happen.

You seem to assume life would have had to develop there. While that is a possibility, there are a lot of other scenarios on how life might have found a niche on a comet exactly like it does here on Earth.

[Kryten]

Wickramasinghe is a man with no biology credentials, a history of making bizarre and erroneous claims about extraterrestrial life, and who provides no real evidence for this specific claim. It's not worth the time to consider it.

[MinimumSky5]

I never believed that story at all, because neither Rosetta nor Philae have the instruments needed to check for the presence of life. It would be like claiming that New Horizons had found a planet orbiting in the habitable zone of a star, it can't find the evidence for that, and it has no business looking as that isn't it's scientific objective.

[Camacha]

I never believed that story at all, because neither Rosetta nor Philae have the instruments needed to check for the presence of life. It would be like claiming that New Horizons had found a planet orbiting in the habitable zone of a star, it can't find the evidence for that, and it has no business looking as that isn't it's scientific objective.

Be careful with that kind of science attitude or approach. Quite often major discoveries were made by people going Huh. That's funny. when their experiment went awry and turned out something totally unexpected. It is kind of the Hold my beer! of science discoveries.

[Ralathon]

Be careful with that kind of science attitude or approach. Quite often major discoveries were made by people going Huh. That's funny. when their experiment went awry and turned out something totally unexpected. It is kind of the Hold my beer! of science discoveries.

Except the vast VAST majority of the time the "Huh, that's funny" turns into a "Oh, that makes sense" or "Damn, miscalibrated the sensor" upon closer inspection.

Remain skeptical until there is repeatable evidence from independent sources that cannot be explained with current theories. When we have that you can start getting hyped.

[KerikBalm]

What I'm fairly convinced of is that this "unequivocal evidence" that one utter charlatan crackpot of a "scientist" has found is nothing of the sort.

+1

Sounds like a picnic for tardigrades, the second most awesome species on Earth.

Overhyped... They can be freeze dried... so what? So can seeds.... nobody would suggest if you put plant seeds on that comet, that they'd take root and grow all over the comet.

[KerbMav]

You seem to assume life would have had to develop there. While that is a possibility, there are a lot of other scenarios on how life might have found a niche on a comet exactly like it does here on Earth.

But how did it get up there?

[heng]

There is this idea (not mine, but can't recall source):

Fact:

- Bacterial or fungal spores... these are small enough to be carried by the wind.

- Strong winds/storms can carry these to pretty great heights.

Speculation:

- If a spore gets high enough by some freak weather conditions... (possible)

- If it somehow gets charged... (possible)

- It could get even higher by travelling with the magnetic currents... (unknown)

- If it gets high enough to be affected by solar winds or other influences, it could eventually leave earth's SOI(*).

Remember, there are rocks on earth, which are from Mars. According to scientific consensus. Granted, leaving Mars by a rather more energetic method...

According to this speculation, earth has been leaving a trail of spores in its wake for billions of years... Most stay 'local', i.e. in the solar system. And only few survive, but some may find conditions to thrive. Extremophiles can endure unbelievably hostile environments.

--

(*) yes, yes, i know. you know what i mean

Edited July 9, 2015 by heng
frigging grammar/spelling typos *scowl*

[lajoswinkler]

There is this idea (not mine, but can't recall source):

Fact:

- Bacterial or fungal spores... these are small enough to be carried by the wind.

- Strong winds/storms can carry these to pretty great heights.

Speculation:

- If a spore gets high enough by some freak weather conditions... (possible)

- If it somehow gets charged... (possible)

- It could get even higher by travelling with the magnetic currents... (unknown)

- If it gets high enough to be affected by solar winds or other influences, it could eventually leave earth's SOI(*).

Remember, there are rocks on earth, which are from Mars. According to scientific consensus. Granted, leaving Mars by a rather more energetic method...

According to this speculation, earth has been leaving a trail of spores in its wake for billions of years... Most stay 'local', i.e. in the solar system. And only few survive, but some may find conditions to thrive. Extremophiles can endure unbelievably hostile environments.

--

(*) yes, yes, i know. you know what i mean

That spore would be killed by the ionizing rays before it gets into interplanetary space. Even if it would survive it, it would take eons until it reaches another planet like Mars. It would impact it at enormous speeds and get turned to plasma.

Therefore in reality, there is zero chance of success for these scenarios.

There are chances of living/dormant stuff being transported inside porous rocks blasted by some impact into space above second cosmic speed, but chances of initial survival are incredibly small (even considering great number microbes fight with). Surviving eons in space and then reentry (where, Venus? LOL) ...

[YNM]

Why we're talking about whether life can survive on a comet when we even haven't figured out the comet inside-out, detailed to the last speckle of dust ? I won't say that extraterrestrial planet can hold life if they're blazing hot or so. Only when they're good enough you'll start to investigate how we can know whether life is there. Same for comets, KBOs, moons, asteroids, planets... Theories Hypothess stays as hypotheses, and when they have little merrit yet pushed over it sometimes deserves to be added called conspiracy theory. Those that can be proven over and over becomes conclusion theories, and that doesn't mean it shouldn't be tested again !

Edited July 9, 2015 by YNM
Correcting - thanks lajoswinkler

[peadar1987]

That spore would be killed by the ionizing rays before it gets into interplanetary space. Even if it would survive it, it would take eons until it reaches another planet like Mars. It would impact it at enormous speeds and get turned to plasma.

Actually, small enough objects don't generally experience significant heating on reentering an atmosphere, as they shed speed a lot more easily than larger, more massive ones, and end up at subsonic speeds very high in the atmosphere: http://www.thenakedscientists.com/HTML/questions/question/3007/

The ionising radiation problem is probably more of a severe one.

[lajoswinkler]

Why we're talking about whether life can survive on a comet when we even haven't figured out the comet inside-out, detailed to the last speckle of dust ? I won't say that extraterrestrial planet can hold life if they're blazing hot or so. Only when they're good enough you'll start to investigate how we can know whether life is there. Same for comets, KBOs, moons, asteroids, planets... Theories stays as theories, and when they have little merrit it sometimes deserves to be added the word "conspiracy". Those that can be proven over and over becomes conclusion, and that doesn't mean it shouldn't be tested again !

You mean hypotheses. These are not theories. Theories have evidence.

Actually, small enough objects don't generally experience significant heating on reentering an atmosphere, as they shed speed a lot more easily than larger, more massive ones, and end up at subsonic speeds very high in the atmosphere: http://www.thenakedscientists.com/HTML/questions/question/3007/

The ionising radiation problem is probably more of a severe one.

Still, for a naked spore any reentry or collision with surface will be lethal.

[Camacha]

Except the vast VAST majority of the time the "Huh, that's funny" turns into a "Oh, that makes sense" or "Damn, miscalibrated the sensor" upon closer inspection.

Remain skeptical until there is repeatable evidence from independent sources that cannot be explained with current theories. When we have that you can start getting hyped.

Oh, yes, I am certainly for being sceptical. Any scientist worth his salt should be. That, however, does not mean you should ignore anomalies until they become overwhelming.

Mind you, I will repeat this over and over, I do think this guy has rather wild theories and I have serious doubts about what he says, but dismissing new and seemingly odd ideas too easily is a mistake we have made too often before. Odd ideas are often ridiculed, but not a problem. Ideas without proof are, but unfortunately, good hints or even evidence it often ignored because it does not fit with the current sciencific understanding.

I am not promoting this guy's ideas in any way, shape or form, I am promoting a healthy open scientific mind along with just the right dose of scepsis.

Therefore in reality, there is zero chance of success for these scenarios.

Absolute statements require absolute proof. Considering a lot of proper, non tinfoil hat scientists consider panspermia to be a viable theory, your statement seems to be erroneous.

[lajoswinkler]

Absolute statements require absolute proof. Considering a lot of proper, non tinfoil hat scientists consider panspermia to be a viable theory, your statement seems to be erroneous.

You did not read the conversation properly. Conditions were established.

[Camacha]

You did not read the conversation properly. Conditions were established.

You mean landing on Venus and such? They are probably plenty of ways how it could not work, you only need one that does. No chance seems to be out of the question.

[lajoswinkler]

If a naked spore somehow survives eons (it will not survive, case closed!), and impacts an atmosphere or surface at interplanetary transfer speeds, it will get destroyed.

This is not quantum mechanics so you can use probabilities. It will get destroyed, but it will be dead long ago because nothing can last that long naked, exposed to space.

[Camacha]

If a naked spore somehow survives eons (it will not survive, case closed!), and impacts an atmosphere or surface at interplanetary transfer speeds, it will get destroyed.

This is not quantum mechanics so you can use probabilities. It will get destroyed, but it will be dead long ago because nothing can last that long naked, exposed to space.

You might want to read up on panspermia, since you seem to be misjudging some probabilties and possibilities. People much more adept than you and I have looked into this and, until now, have found no reason to believe it is not reasonably possible (though different experts will of course have different opinions). That does not mean it has happened, it simply means it still on the table.

The numbers involved are quite mind-boggling indeed, I can imagine you have trouble wrapping your head around those.

[pincushionman]

Anyone else read the possible very exciting news today? Evidence of life inside the comet. Please read!!

We've been talking about this for the last five pages, but has anyone actually posted a link to where this was even discussed? The links in majorjim's posts go to a Twitter link with a video about an update from LCC. Is the discussion of life in that video somewhere? All the this talk about "this <various description> scientist" seems to say it's someone else entirely.