chemistry of life part 2

Question 1

why is there optimism about finding extraterrestrial life, even in our solar systems?

Answer 1

Due to the amount of extremophiles living on earth, in conditions of high temperature and high salinity, and inside rocks

Question 2

what is a halophile?

Answer 2

salt loving creature

Question 3

what is a biosignature is what?

Answer 3

any evidence or indication of life, living or dead. it can be chemical or morphological in nature

Question 4

what is the most important biosignature?

Answer 4

Liquid water

Question 5

What are some more complex biosignatures?

Answer 5

carbs, lipids, proteins, nucleic acids.

the more complex biosignature you find the more likely it is to have had biogenic origin

Question 6

What is racemization?

Answer 6

one enantiomer can spontaneously turn into the other one

Question 7

what biosignature is the most relevant to finding/studying alien life?

Answer 7

an atmosphere that is not in chemical equilibrium

Question 8

why is the earths atmosphere not in equilibrium?

Answer 8

due to the presence of life, methane and o2 are waste gases from organisms

Question 9

how might we be able to look for life on mars? (7)

Answer 9

look for waste gasses

methane, o2

but also other ones such as;
formaldehyde and methanol

also might look for
chirality

isotopic ratios found only in life

morphological biosignatures

Question 10

How do we study Mars for evidence of life, present or past? (4)

Answer 10

telescopes

uncrewed probes 
(flybys, orbiters, landers, rovers, sample return missions) 

meteorites from mars

human crewed missions

Question 11

Ancient mars (3-4 billion years ago) had what? (5)

Answer 11

geological activity (volcanoes)

a liquid core that produced a magnetic field

a thick atmosphere of co2 and water vapour that was protected by the magnetic field from solar wind and cosmic rays

higher temperatures

large bodies of water

Question 12

What did Allan Hills find?

Answer 12

ALH 84001 A several billion year old meteorite that had been ejected from mars 16 million years ago and landed on earth 13000 years ago

Question 13

What was interesting about ALH 84001?

Answer 13

organic molecules - polycyclic hydrocarbons

magnetite that might have a biological origin

shapes that look like tiny bacteria

Question 14

What is Panspermia?

Answer 14

life can travel from one plant to another in our solar system

Question 15

What happened to Mars? (4)

Answer 15

The core solidified, geological activity stopped, and the magnetic field weakened

solar wind striped away much of the atmosphere which was no longer replenished by volcanic activity

most of the water was blasted into space from meteor impacts.

the remaining water froze in subsurface layer

Question 16

the study of mars today:

what is the current condition of the atmosphere?

Answer 16

very thin, it is 1% of the earths atmosphere 96% co2 traces of o2 methane and carbon monoxide

Question 17

the study of mars today:

what is the current condition of the temperature?

Answer 17

very cold, but near the equator when sun is around it can be 0 degrees and ground could be up to 20 degrees

Question 18

the study of mars today:

what is the current condition of the geology?

Answer 18

no geological activity

Question 19

the study of mars today:

what is the current condition of the radiation?

Answer 19

it has a lot of radiation

Question 20

What was the purpose of the Viking lander

Answer 20

to look for traces of life, but came up empty.

Question 21

What did the ground based observations, the mars express orbiter and curiosity rover detect in trace amounts on mars? what does this mean?

Answer 21

Methane

possible means that there was life?

methane is a biosignature and there is a variation in the concentration of methane in terms of latitude

Question 22

What are the possible sources of martian methane? (2)

Answer 22

living origin

at high temp and pressure olivine rock and water mixed produced methane

it is very ambiguous sign

Question 23

What are recurring slope linae?

Answer 23

Suggests that liquid water still flows periodically on mars, although this conclusion is disputed, the streaks are dark colourations

Question 24

What did the phoenix lander in 2008 discover? (3)

Answer 24

touched down near the north polar cap

subsurface water ice
snow

perchlorate, a strong oxidant which some organisms can use for energy

Question 25

What did the curiosity rover find?

Answer 25

detected a transient spike in methane

Question 26

What is the Exomars rover ? what will it have/what is its mission?

Answer 26

Will have large instrument package, including a drill that can go 2 meters below the surface

will carry a large lab that can look for water ice, biosignatures and mineral composition of the surface