Chemistry of Life 2 - MT1 - Part 2 Flashcards
When was the solar system formed?
4-6 billion years ago
- life appeared shortly after that
Approx. 3-4 billion years ago Mars had what? (2)
- Geological activity
- volcanoes - A liquid core produced by a magnetic field
What is the biggest mountain on Mars?
Olympus
What can renew in the atmosphere?
Volcanoes
What does the magnetic field provide protection from? (4)
- Solar wind
- Cosmic rays
- High temps
- Large bodies of water
What acts as a warming blanket?
CO2
- earth would be 30deg C cooler if we did not have an atmosphere
What have been found on earth from Mars?
Meteorites
- found over 100
What was the most significant find on Mars?
Allan Hills 84001 (ALH84001)
- determined it was several billion yeas old from radio carbon dating
Lithopanspermia
Is a version of the pansoermia hypothesis in which it is argued that impact expelled rocks from a planets surface serve as transfer vehicles for spreading biological material from one solar system to another
- idea that life travels on rocks
What was interesting about ALH84001? (3)
- Contained organic molecules
- polycyclic hydrocarbons - Magnetite that might have a biogenic origin
- appeared in the magnetite in crystal form (Fe3O4) - Shapes that looked like tiny bacteria
- nanobacteria
Magnetite
Magnetic material that consists of an oxide of iron and is an important form of iron
Why are people not convinced about nanobacteria?
Because they thought that they were too small for anything to live on
What has happened to Mars between then and now? (6)
- Its core solidified
- Geological activity stopped
- Magnetic field weakened
- The solar wind stripped away much of the atmosphere, which was not getting replenished by the volcanoes
- Most of the water was blasted into space by meteor imacts
- The remaining water froze in subsurface layers
- below the surface
What was getting lost when the atmosphere was getting lost?
A lot of water was being lost in the atmosphere and it lead to a decrease in the warming effect of the atmosphere
What are the atmospheric conditions on Mars? (4)
- 1% of earths atmosphere
- 96% CO2
- Traces of CO, O2 and CH4
- Atmosphere is thin
What is the temp like on Mars? (2)
- -90deg C
- Near the equator the temperature can increase to 0 and the ground temperature can increase to 20deg C
What is the geological activity like on Mars?
There is none
What is the radiation like on Mars?
Need some protection against the radiation
What is an example of radiation on Mars?
Cosmic rays
What was the Viking landers (1976) designed to do?
Test for the presence of living processes
- but came up empty
GCMS
The Gas Chromatography-Mass Spectrometry
What was GCMS used for?
Used to separate potential organic molecules in
Labeled Release experiment (4)
- 7 nutrients carried by probes and labelled with 14CO2
- added soil and waited for radioactive CO2 to appear
- found radioactive CO2 released
- couldnt make a claim
What 2 ground observations detected CH4?
- Mars express orbiter
2. Curiosity rover
What are 5 possible sources of martian methane?
- Live origin possible
- Olivene (rock) can mix with water to produce CH4
- Brought in by cosmic dust
- Microbes
- Seasonal aspect
What exits today at the polar caps and in the lower latitudes under the soil surface?
Water ice
What did the pictures from the Mars globe surveyor suggest?
That liquid water still flows periodically on Mars
- this conclusion got disputed
What did the phoenix lander discovered? (3)
- Subsurface water ice
- Snow
- Perchlorate
Perchlorate
A strong oxidant which some organisms can use for energy
The curiosity rover (2012-present)
- Detected traces of CH4
- Lasted longer than any other rover on Mars
What was the goal of ExoMars Trace Gas Orbiter and Lander?
Sensitive detection and mapping of CH4 and other trace gases with an attempt to determined their origin
- had an error in measurement unit navigator system
- thought it had landed and it didnt because it ended up crashing
ExoMars rover
- Will have a large instrument package, including a drill that can go down 2m below the surface (thats where the ice is)
- Will carry large labs that can look for water ice, biosignatures and mineral compositions for the surface
- Scoop up material and bring it back to earth
- Raising the issue for contamination
