A Space & astronomy forum. SpaceBanter.com

If this is your first visit, be sure to check out the FAQ by clicking the link above. You may have to register before you can post: click the register link above to proceed. To start viewing messages, select the forum that you want to visit from the selection below.

Go Back   Home » SpaceBanter.com forum » Astronomy and Astrophysics » Research
Site Map Home Authors List Search Today's Posts Mark Forums Read Web Partners

Astronomy and Biology



 
 
Thread Tools Display Modes
  #1  
Old January 7th 18, 03:52 PM posted to sci.astro.research
jacobnavia
external usenet poster
 
Posts: 97
Default Astronomy and Biology

They meet in Mars exploration.

Since quite a time, humans are roving the planet, "looking for life".
Sadly, I think that this is not the case.

Biology has taken the smallest part of exploration, with Geology getting
the headlines. There are no specific sensors looking for life in those
machines (there isn't even a microscope), and all information comes from
side effects of other observations.

Anyway, it is better than nothing of course.

Life has metabolism, and the effects of that metabolism are gases that
are produced as side effects of being alive. Methane is one such a gas.

Methane is detected regularly in Mars and has a seasonal pattern.
Curiosity, the U.S. rover wandering around in Mars, detected a spike in
methane concentration that surpassed greatly the almost inexistent
background concentration of that gas.

Did the rover turn around and return to the hot spot to investigate this
matter?

No. It just went on wandering around.

Two peer reviewed journals publish articles from micro-biologists that
identify fossils in the ground.

Did the rover turn around and investigate what really those things are?

No, it just keep on going, wandering about.

In desperation I wrote in an ISS astronaut's web site a letter to him.

Please Sir, can you tell anybody to turn those rovers around and
investigate that?

Never got any answer.

NASA is driving those rovers, and it is not looking for any life.

A Viking lander engineer remarked that the rock in front of the camera
changed color in spring. Spectral analysis gave similar spectra to
lichens.

Magnetite is found in Mars meteorites, photographs of small worms are
published, etc. Humans have acquired a lot of data, but no conclusions
are drawn.

Life in Mars exists, and it is very similar to earth life.

Is this a new planetary genesis?

Or both Mars and Earth life have a common origin?

We will get an answer to this question when we examine the genetic code
of Mars life. If it is the same code, odds are high that it is a common
origin. If the code used is different, the common origin becomes more
improbable.

Farther away we have the biggest ocean of the solar system in Europa.
Colored, red material is detectable in the surface. We know that life
can thrive in total darkness, as sea floor bacterial communities
testimony here on earth.

In all those places, we could find life as we know it, since the
temperatures are mostly earth like.

Titan, however, is much more a challenge for life. Methane is there in
BIG quantities, and there is a very complex organic chemistry happening
in the atmosphe an orange haze that clouds the whole satellite. There
is a fluid cycle, with lakes of methane and ethane, rivers, rain, etc,
at around -200 Celsius.

That would be life as we do not know it. Water is rock solid at those
temperatures, and methane and ethane are the universal solvents.
Recently, researchers proved that a membrane can be constructed in those
solutions.

Those beings would be radically different from us. Life as we do not
know it.

Farther away we have evidence of molecular clouds with complex organic
compounds. Organic molecules are discovered in huge quantities.

OK.

Microbes.

But aliens? Intelligent beings?

Life can evolve intelligence, symbolic language, and even astronomy. We
are the product of natural evolution.

Physical laws are the same here and elsewhere. There are billions and
billions of planets in our galaxy. Why aren't "they" talking to us?

Where is everybody? said von Neuman.

Well, in any case they do not use radio waves, why should they?
Neutrinos are much better for communications since they aren't deflected
by matter as photons are. But we are unable to listen to anything using
neutrinos, so we do not hear anything.

Scientific work implies a belief. This sounds preposterous but it is at
the base of every scientific observation. You make the hypothesis that
this or that phenomena exist, and you try to figure out and measure the
consequences.

To find something, you have to believe it exists. For instance dark
matter. Many astronomers believe this thing exists and they try (with no
success so far) to measure a consequence of that hypothetical object.

We have to get to the same level when looking for alien life. If you are
convinced that it doesn't exist, you will never find it.

Ads
  #2  
Old January 10th 18, 09:09 PM posted to sci.astro.research
brad
external usenet poster
 
Posts: 100
Default Astronomy and Biology

jacobnavia
They meet in Mars exploration.

Since quite a time, humans are roving the planet, "looking for life".
Sadly, I think that this is not the case.

Biology has taken the smallest part of exploration, with Geology getting
the headlines. There are no specific sensors looking for life in those
machines (there isn't even a microscope), and all information comes from
side effects of other observations.

I believe there is a specific bio test being performed right now.

Anyway, it is better than nothing of course.

Life has metabolism, and the effects of that metabolism are gases that
are produced as side effects of being alive. Methane is one such a gas.

Methane is detected regularly in Mars and has a seasonal pattern.
Curiosity, the U.S. rover wandering around in Mars, detected a spike in
methane concentration that surpassed greatly the almost inexistent
background concentration of that gas.

There is ample evidence for abiotic methane. This has been suspected
for quite some time. I believe first proposed by Soviet Geologists in
the 1950's. Here's a link to a new open access paper detailing
a process for abiotic methane.
/https://www.nature.com/articles/ncomms14134

  #3  
Old January 12th 18, 10:09 AM posted to sci.astro.research
jacobnavia
external usenet poster
 
Posts: 97
Default Astronomy and Biology

Le 10/01/2018 =C3=A0 22:09, brad a =C3=A9crit=C2=A0:
There is ample evidence for abiotic methane. This has been suspected
for quite some time. I believe first proposed by Soviet Geologists in
the 1950's. Here's a link to a new open access paper detailing
a process for abiotic methane.
/https://www.nature.com/articles/ncomms14134


1) The process of abiotic methane production occurs at great depth and
pressures on earth. Earth has tectonic plate movements, Mars doesn't.
Since in Mars everything is fixed since aeons, this process should have
finished long ago.

2) Why would an abiotic process have seasonal variations?

3) An abiotic process would yield a fixed methane concentration in the
planet, what is not observed.

[[Mod. note -- Volcanos are an abiotic phenomenon which can lots of
methane, with amounts varying across time/space. I (myself) don't know
if we (the scientific community) know enough about Martian "geology"
(areology??) to rule out current (ongoing) subduction and/or volcanism.

Another abiotic process would be solar heating causing underground
deposits to melt/vaporize/sublimate. We'd expect this to vary seasonally.
-- jt]]
  #4  
Old January 12th 18, 10:27 AM posted to sci.astro.research
Steve Willner
external usenet poster
 
Posts: 1,140
Default Astronomy and Biology

In article ,
jacobnavia writes:
There are no specific sensors looking for life in [Mars rovers]
(there isn't even a microscope),


[[Mod. note -- Some experiments specifically designed to look for life
were landed on Mars in 1976. They found some surprising chemistry, but
no unambiguous evidence of life:
https://en.wikipedia.org/wiki/Viking_program

The underlying engineering problem is that while detecting macroscopic
life is fairly easy (take pictures of it), detecting *microscopic* life
requires fairly heavy/bulky equipment which is normally designed to be
operated directly by skilled humans. So doing this by remote control
from 45 light-minutes away (and with zero ability for a human to fix
anything that doesn't work) is hard, i.e., difficult to develop and
make work properly. That difficulty means lots and lots of engineering
person-years to develop the mission, which makes the mission very
expensive (on a scale of planetary-science budgets).

Given a budget of (say) 5e9 {US$,Euro}/year, one could do some very
sophisticated searches for life on Mars. But the actual worldwide budget
for all Martian exploration is well under 0.5e-9 {US$,Euro}/year, so
progress is slow.

And despite what optimists like Zubrin/Musk might say, sending (living)
humans to Mars wouldn't be cheap, either.
-- jt]]

There's no high-magnification microscope, probably because preparing
samples for one would have required complex and heavy
instrumentation. MAHLI has a resolution of around 25 microns
https://msl-scicorner.jpl.nasa.gov/Instruments/MAHLI/
but I don't know how useful it has been in practice.

Life has metabolism, and the effects of that metabolism are gases that
are produced as side effects of being alive. Methane is one such a gas.


I wouldn't mind seeing a chiral labeled release experiment sent to
Mars, but so far it hasn't ranked high enough in the priority lists.

In desperation I wrote in an ISS astronaut's web site a letter to him.


The human spaceflight program is quite separate from the planetary
science program. See nasa.gov for contact addresses for the latter.
Even for human spaceflight, the astronauts do not make policy, though
they certainly influence it.

Where is everybody? said von Neuman.


Fermi. The Fermi Paradox is a good argument against intelligent
extraterrestrial life, though it is far from conclusive.

Well, in any case they do not use radio waves, why should they?
Neutrinos are much better for communications since they aren't deflected
by matter as photons are.


Neutrinos are hard to detect. You might want to compare the
respective energy requiremets.

To find something, you have to believe it exists.


Yes, that's why Galileo never found sunspots or the moons of Jupiter:
he had no pre-existing conception that they existed. ... Oh, wait...

For instance dark matter.


No doubt Fritz Zwicky found dark matter only because he believed it
existed and was looking for it.

Actually, the history is the other way around: astronomers were
unwilling to accept dark matter -- despite strong evidence -- until
the evidence became overwhelming.

Many astronomers believe this thing exists and they try (with no
success so far) to measure a consequence of that hypothetical object.


Galaxy cluster velocity dispersions? Galaxy rotation curves?
Microwave background fluctuations? Gravitational lensing? Dwarf
galaxy velocity dispersions?

We have to get to the same level when looking for alien life. If you are
convinced that it doesn't exist, you will never find it.


I don't think anyone -- perhaps barring a few cranks -- is convinced
extraterrestrial life doesn't exist. There are active searches in
progress and more planned for the future. What priority to give
potential searches, in comparison to other projects competing for
funding, is a difficult judgment question.

--
Help keep our newsgroup healthy; please don't feed the trolls.
Steve Willner Phone 617-495-7123
Cambridge, MA 02138 USA
  #5  
Old January 12th 18, 06:00 PM posted to sci.astro.research
Martin Brown[_3_]
external usenet poster
 
Posts: 146
Default Astronomy and Biology

On 12/01/2018 11:27, Steve Willner wrote:
In article ,
jacobnavia writes:
There are no specific sensors looking for life in [Mars rovers]
(there isn't even a microscope),


[[Mod. note -- Some experiments specifically designed to look for life
were landed on Mars in 1976. They found some surprising chemistry, but
no unambiguous evidence of life:
https://en.wikipedia.org/wiki/Viking_program

The underlying engineering problem is that while detecting macroscopic
life is fairly easy (take pictures of it), detecting *microscopic* life
requires fairly heavy/bulky equipment which is normally designed to be
operated directly by skilled humans. So doing this by remote control
from 45 light-minutes away (and with zero ability for a human to fix
anything that doesn't work) is hard, i.e., difficult to develop and
make work properly. That difficulty means lots and lots of engineering
person-years to develop the mission, which makes the mission very
expensive (on a scale of planetary-science budgets).


I thought there was a project underway to send a small stable isotope
mass spectrometer to look for any variation of deltaC13 or deltaS34 in
the rocks that would be indicative of life. Life preferentially
concentrates the lighter isotopes making inorganic materials have a
higher concentration of the heavier isotopes. eg.

https://ntrs.nasa.gov/archive/nasa/c...9890016972.pdf

The challenge is making one that can survive the stresses of launch
without being to heavy and do its own sample prep. Increasing AI power
will make it possible sooner rather than later but I expect there may be
a few disappointments along the way. Mars with its very thin atmosphere
is particularly hard to do a soft landing on.

Some of the historic articles about what the Viking mission achieved
with its mass spectrometers is online at:

http://onlinelibrary.wiley.com/doi/10.1002/jms.396/full

Given a budget of (say) 5e9 {US$,Euro}/year, one could do some very
sophisticated searches for life on Mars. But the actual worldwide budget
for all Martian exploration is well under 0.5e-9 {US$,Euro}/year, so
progress is slow.

And despite what optimists like Zubrin/Musk might say, sending (living)
humans to Mars wouldn't be cheap, either.
-- jt]]


Sending humans to Mars would be more like "Big Brother" with teeth. You
would also have to send a substantial robotic automated medical facility
there to give them rehab when they arrived. Easier, cheaper and much
less risky all around to send smart autonomous robust robotic probes.

Life has metabolism, and the effects of that metabolism are gases that
are produced as side effects of being alive. Methane is one such a gas.


I wouldn't mind seeing a chiral labeled release experiment sent to
Mars, but so far it hasn't ranked high enough in the priority lists.


I think there were plans to send something using stable isotope labelled
likely foods and look for the characteristic signs of life in the waste
gasses. The challenge is as ever in distinguishing between inorganic
peroxide soil reactions and actual life metabolic processes. The idea
was that the observed isotope ratios would be different.

It would be extremely exciting to find independent life evolved anywhere
else in the solar system - although we need to take great care not to
contaminate pristine planetary environments with our own form of life.
ISTR some bacteria on the lunar lander Surveyor 3 that Apollo 12 visited
were still viable after 3 years on the moon.

https://science.nasa.gov/science-new.../ast01sep98_1/

--
Regards,
Martin Brown

  #6  
Old January 16th 18, 10:30 PM posted to sci.astro.research
jacobnavia
external usenet poster
 
Posts: 97
Default Astronomy and Biology

Le 07/01/2018 à 16:52, jacobnavia a écrit :
We have to get to the same level when looking for alien life. If you are
convinced that it doesn't exist, you will never find it.


The answers I got weren't really satisfying.

Why can't that dammed rover turn around and look if there is anything
breathing in the soil?

I said:

To find something, you have to believe it exists.


Steve answered:

Yes, that's why Galileo never found sunspots or the moons of Jupiter:
he had no pre-existing conception that they existed. ... Oh, wait...

Look, he did not look away when they appeared before his eyes. The
problem with Mars life is that we do not look for it and our rover goes
on. No further investigation is needed, humans look away.

In another post, Brad answered:

There is ample evidence for abiotic methane. This has been suspected
for quite some time. I believe first proposed by Soviet Geologists in
the 1950's. Here's a link to a new open access paper detailing
a process for abiotic methane.
/https://www.nature.com/articles/ncomms14134

Of course, it could be abiotic methane. But isn't worth investigating that?

Why would abiotic methane, produced at great depths and temperatures
here on earth as that paper explains, have a seasonal appearence? In
spring... that looks suspicious to me.

If it is abiotic it would be at least an answer. But it is not deemed
necessary just to investigate!

We just look away.

  #7  
Old January 17th 18, 02:06 PM posted to sci.astro.research
brad
external usenet poster
 
Posts: 100
Default Astronomy and Biology

[[Mod. note -- This article arrived in my moderation inbox with the
quoting a little bit confused. I have fixed this up by hand editing.
I apologise if I've mistakenly misattributed anyone's words to someone
else.
-- jt]]

jacobnavia wrote:
The answers I got weren't really satisfying.

In another post, Brad answered:

There is ample evidence for abiotic methane. This has been suspected
for quite some time. I believe first proposed by Soviet Geologists in
the 1950's. Here's a link to a new open access paper detailing
a process for abiotic methane.
/https://www.nature.com/articles/ncomms14134

Of course, it could be abiotic methane. But isn't worth investigating that?

Why would abiotic methane, produced at great depths and temperatures
here on earth as that paper explains, have a seasonal appearence? In
spring... that looks suspicious to me.

If it is abiotic it would be at least an answer. But it is not deemed
necessary just to investigate!

We just look away.


I guess my response is obscure. So I'll elucidate. The Curiosity rover is
designed to look for signs of life. Specifically methane. Your post seemed
to imply that biogenic methane was the only type. So I offered a link to
a paper on abiogenesis.

So why is it relevant? Because ultra mafics on earth are deep but,
on Mars they are on the surface. Basalt. As evidenced by only shield
volcanoes on Mars. The surface of mars is basalt, whereas, basalt
underlies oceans or continents on earth. So it seemed reasonable
to look for near surface processes near volcanoes on Mars, and where
any exposed carbonates may be present. An impact crater near a
volcanic province. That's where it is.

ie: look for water, basalt, some source of carbon and assume shallow
genesis.

Serpentinization (water reacting with basalt) releases (at low ~100C
temp)H2 which in turn reacts with CO2 associated with hydrothermal
intrusions associated with volcanism.

In any endeavor one must first develop a plan of action. Then that
plan must be followed.
Any deviation obscures the results and adds chaos more than any
perceived temporary gain. That rover carries instrumentation to do
exactly what you want. My opinion, let them follow their plan.

My understanding is the 2020 rover will have the instrumentation
to detect the C12/C13 ratio in the methane to give a more definitive
answer to the type being released. See here.
http://exploration.esa.int/mars/46038-methane-on-mars/

Sorry for my original disjointed post.

Brad
  #8  
Old January 17th 18, 09:59 PM posted to sci.astro.research
Steve Willner
external usenet poster
 
Posts: 1,140
Default Astronomy and Biology

In article ,
Martin Brown writes:
I thought there was a project underway to send a small stable isotope
mass spectrometer to look for any variation of deltaC13 or deltaS34 in
the rocks that would be indicative of life. Life preferentially
concentrates the lighter isotopes making inorganic materials have a
higher concentration of the heavier isotopes. eg.

https://ntrs.nasa.gov/archive/nasa/c...9890016972.pdf


Distinguishing between life and abiotic chemistry is the reason for
doing _chiral_ labeled release. Life should prefer one enantiomer
over the other, while abiotic processes should show little or no
preference.

Anybody know when or why 'stereoisomers' became 'enantiomers'?

--
Help keep our newsgroup healthy; please don't feed the trolls.
Steve Willner Phone 617-495-7123
Cambridge, MA 02138 USA
  #9  
Old January 21st 18, 03:43 PM posted to sci.astro.research
Martin Brown[_3_]
external usenet poster
 
Posts: 146
Default Astronomy and Biology

[[Mod. note -- My apologies for the delay in processing this article;
which arrived in my moderation inbox on 2018-01-19. -- jt]]

On 17/01/2018 22:59, Steve Willner wrote:
In article ,
Martin Brown writes:
I thought there was a project underway to send a small stable isotope
mass spectrometer to look for any variation of deltaC13 or deltaS34 in
the rocks that would be indicative of life. Life preferentially
concentrates the lighter isotopes making inorganic materials have a
higher concentration of the heavier isotopes. eg.

https://ntrs.nasa.gov/archive/nasa/c...9890016972.pdf


Distinguishing between life and abiotic chemistry is the reason for
doing _chiral_ labeled release. Life should prefer one enantiomer
over the other, while abiotic processes should show little or no
preference.


Not sure you need to use chiral labelled reagents.

You could feed the critters a racemic mixture and then measure any
change in the angle of rotation of plane polarised light if there was
any difference in the rate of reaction for the two forms.

I suspect there may well be some abiotic reactions on clay surfaces that
do show a preference for handedness if that is how life got started.

Anybody know when or why 'stereoisomers' became 'enantiomers'?

They were called D and L optical isomers first because of the effect
their solutions had on rotating plane polarised light. Essentially
materials with the same chemistry but different effect on light.

Some crystals, sugars and naturally occurring amino acids solutions
first observed to do this in 1813 by Biot and explained in 1874 by Hoff
as being due to an asymmetric tetrahedral carbon atom in the molecule.

I think the preferred names are down to IUPAC.

Enantiomers are strictly non superposable mirror images of each other
whilst (dia)stereoisomers can include other things as well.

http://goldbook.iupac.org/html/D/D01679.html

Still chiral molecules but not related as exact mirror images.

--
Regards,
Martin Brown
  #10  
Old January 28th 18, 10:48 AM posted to sci.astro.research
Steve Willner
external usenet poster
 
Posts: 1,140
Default Astronomy and Biology

[I thought I'd replied before, but it seems not to have gotten
through. Apologies if it shows up twice.]

[[Mod. note -- I don't recall seeing it. -- jt]]

In article ,
Martin Brown writes:
Not sure you need to use chiral labelled reagents.

You could feed the critters a racemic mixture and then measure any
change in the angle of rotation of plane polarised light if there was
any difference in the rate of reaction for the two forms.


Sorry, but I can't visualize how that would work. What would be
needed to prepare the sample? Viking had a labeled release
experiment (which showed positive results based on pre-flight
criteria), and a similar experiment with chiral reagents should be
only a little more complex.

I suspect there may well be some abiotic reactions on clay surfaces that
do show a preference for handedness if that is how life got started.


Have those been seen anywhere?

I think the preferred names are down to IUPAC.

Enantiomers are strictly non superposable mirror images of each other
whilst (dia)stereoisomers can include other things as well.
http://goldbook.iupac.org/html/D/D01679.html
Still chiral molecules but not related as exact mirror images.


Thanks! As far as I can tell, "stereoisomers" is the general term,
which includes both enantiomers and diastereoisomers. The latter
have more than one stereocenter and are mirror images in some but not
all. I've learned something.

--
Help keep our newsgroup healthy; please don't feed the trolls.
Steve Willner Phone 617-495-7123
Cambridge, MA 02138 USA
 




Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
REAL ALCHEMY Within BIOLOGY [email protected] Astronomy Misc 13 January 6th 08 06:06 AM
Algebraic Statistics and Computational Biology Karen Li Astronomy Misc 0 October 25th 07 04:57 AM
New 'superlens' will revolutionize astronomy, medicine, biology. Robert Clark Astronomy Misc 4 March 3rd 07 09:06 PM
ALCHEMY For BIOLOGY [email protected] Astronomy Misc 1 November 21st 06 01:35 AM
alien biology Zdenek Jizba Astronomy Misc 7 October 18th 05 12:43 AM


All times are GMT +1. The time now is 10:38 AM.


Powered by vBulletin® Version 3.6.4
Copyright ©2000 - 2018, Jelsoft Enterprises Ltd.
Copyright ©2004-2018 SpaceBanter.com.
The comments are property of their posters.