biosignatures (week 6)

Question 1

what are organics

Answer 1

have carbon or hydrogen as part of their structure

Question 2

what mission helped to find biosignatures

Answer 2

• NASA viking mission of 1976
• 2 orbiters and 2 landers, where experiments were conducted on atmopsheric and soil composition, meteorology and seismology
• ## look for evidence of microbial life in martian soil

Question 3

what experiments were done with the viking landers

Answer 3

• labelled release of carbon- positive
• gas exchange
• pyrolytic release
• GC-MS instrument to measure organics in Martian soil
• NO ORGANICS FOUND!!

Question 4

why was the labelled release experiment conducted positive

Answer 4

• robotic arm used in 2008 to find this out
• salt perchlorate destroys organics- the carbon based nutrients reacted to produce CO2
• ## GC-MS negative as native organics destroyed upon heating

Question 5

were organics ever found on mars

Answer 5

• nasa curiosity found organics in the soil
• ## in 2013 methane was detected in situ on mars (shown that this was seasonal and localised in 2018)

Question 6

where did the methane on mars come from

Answer 6

• interaction between subsurface rocks and liquid water
• microbial life—> methanogens