Author Topic: The Labeled Release experiment on the Viking mission  (Read 24338 times)

Offline Dalhousie

  • Senior Member
  • *****
  • Posts: 2749
  • Liked: 753
  • Likes Given: 1119
Re: The Labeled Release experiment on the Viking mission
« Reply #60 on: 11/20/2023 12:28 am »
What is interesting too is Biemann take on the matter - in 1978 and near the end of his life: since he lived long enough to heard about that perchlorate thing : he died in 2016.

https://en.wikipedia.org/wiki/Klaus_Biemann

When he made his conclusions in 1978 he wasn't that far off the mark (with 20/20, 100% hindsight of course !).
I mean, he had the correct intuition: that some solvant inside his instrument ovens had destroyed the organics when actually looking at them - and quite logically brought a negative result.
He just got the "hot solvant" wrong. He suggested it was NASA chemicals used to sterilize the ovens. Not quite: it was from Mars itself: perchlorates...   :o

Biemann himself had a interesting debate with other scientists, related to perchlorates and his instrument. Must have been fascinating to get new results after 30 years (1978 - 2008) but also perhaps a little painful.

https://www.google.com/search?q="klaus+biemann""perchlorates"

[zubenelgenubi: Wow! Very overly-long search thread truncated.]

Rafael Navarro-González and Chris McKay responded to Biemann's comments

https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2011JE003880
Apologies in advance for any lack of civility - it's unintended

Online Emmettvonbrown

  • Full Member
  • **
  • Posts: 211
  • Liked: 105
  • Likes Given: 509
Re: The Labeled Release experiment on the Viking mission
« Reply #61 on: 11/21/2023 04:01 am »
The exchange was nail bitting at times. Not easy perhaps for Biemann, near the end of his life, to reopen the case he thought he had closed in 1978 (NASA solvants). Old wounds.

Offline Eric Hedman

  • Senior Member
  • *****
  • Posts: 2298
  • The birthplace of the solid body electric guitar
  • Liked: 1945
  • Likes Given: 1127
Re: The Labeled Release experiment on the Viking mission
« Reply #62 on: 02/08/2024 07:40 am »
What I have wondered about on recent Mars probes is why don't they put a microscope on board that could see a microbe in the samples collected.  There are desktop electron microscopes available that could do the job.  Do they draw too much power to be carried onboard?  Can they not be miniaturized enough?  Would it be too difficult to prepare a sample for viewing?  I am just curious if anyone knows the answer.

Offline whitelancer64

What I have wondered about on recent Mars probes is why don't they put a microscope on board that could see a microbe in the samples collected.  There are desktop electron microscopes available that could do the job.  Do they draw too much power to be carried onboard?  Can they not be miniaturized enough?  Would it be too difficult to prepare a sample for viewing?  I am just curious if anyone knows the answer.

Several Mars probes have had microscopes. The Phoenix lander had two microscopes, an optical one and an atomic force microscope. Spirit and Opportunity both had microscopic imagers. Curiosity's MAHLI has a maximum resolution of 14 microns per pixel. Perseverance's SHERLOC has a context camera with a maximum resolution of 10 microns per pixel.
« Last Edit: 02/08/2024 03:40 pm by whitelancer64 »
"One bit of advice: it is important to view knowledge as sort of a semantic tree -- make sure you understand the fundamental principles, ie the trunk and big branches, before you get into the leaves/details or there is nothing for them to hang on to." - Elon Musk
"There are lies, damned lies, and launch schedules." - Larry J

Offline Eric Hedman

  • Senior Member
  • *****
  • Posts: 2298
  • The birthplace of the solid body electric guitar
  • Liked: 1945
  • Likes Given: 1127
Re: The Labeled Release experiment on the Viking mission
« Reply #64 on: 02/09/2024 01:08 am »
What I have wondered about on recent Mars probes is why don't they put a microscope on board that could see a microbe in the samples collected.  There are desktop electron microscopes available that could do the job.  Do they draw too much power to be carried onboard?  Can they not be miniaturized enough?  Would it be too difficult to prepare a sample for viewing?  I am just curious if anyone knows the answer.

Several Mars probes have had microscopes. The Phoenix lander had two microscopes, an optical one and an atomic force microscope. Spirit and Opportunity both had microscopic imagers. Curiosity's MAHLI has a maximum resolution of 14 microns per pixel. Perseverance's SHERLOC has a context camera with a maximum resolution of 10 microns per pixel.
Is it safe to assume that none of these have imaged anything that looks like a microbe on Mars?

Offline Dalhousie

  • Senior Member
  • *****
  • Posts: 2749
  • Liked: 753
  • Likes Given: 1119
Re: The Labeled Release experiment on the Viking mission
« Reply #65 on: 02/15/2024 01:38 am »
What I have wondered about on recent Mars probes is why don't they put a microscope on board that could see a microbe in the samples collected.  There are desktop electron microscopes available that could do the job.  Do they draw too much power to be carried onboard?  Can they not be miniaturized enough?  Would it be too difficult to prepare a sample for viewing?  I am just curious if anyone knows the answer.

Several Mars probes have had microscopes. The Phoenix lander had two microscopes, an optical one and an atomic force microscope. Spirit and Opportunity both had microscopic imagers. Curiosity's MAHLI has a maximum resolution of 14 microns per pixel. Perseverance's SHERLOC has a context camera with a maximum resolution of 10 microns per pixel.
Is it safe to assume that none of these have imaged anything that looks like a microbe on Mars?

Bacteria are typically 3-4 microns so these instruments could not resolve them.  Mineralised microbial cells or filaments are larger and could, in principle, be imaged. 
Apologies in advance for any lack of civility - it's unintended

Tags:
 

Advertisement NovaTech
Advertisement Northrop Grumman
Advertisement
Advertisement Margaritaville Beach Resort South Padre Island
Advertisement Brady Kenniston
Advertisement NextSpaceflight
Advertisement Nathan Barker Photography
1