The London Scale of Extraterrestrial-Life Discovery

Discovery of extra-terrestrial life: assessment by scales of its importance and associated risks | Philosophical Transactions of the Royal Society of London A: Mathematical, Physical and Engineering Sciences proposes a "London Scale" in analogy with the Rio Scale.

Type of Life	(5) completely alien life form (4) likely to be non-terrestrial, but some uncertainty remains (3) life definitely, but a previously unknown variant of terrestrial life (in structure or composition) (e.g. if DNA is present, different amino acids are used) (2) terrestrial-type life form, but some uncertainty remains (1) possible signature of life, but indirect information only (e.g. volatile, trace)
Nature of the Evidence	(6) complex life (high level of organization) (5) simple life (low level of organization) (4) extant life with suspended functioning (like a spore) (3) uncertain whether living or not (like a virus) (2) fossilized life or remnants of life forms (1) biomarkers (indirect evidence, like volatiles, metabolites, biochemical signatures, etc.)
Method of Discovery	(5) by analysing the result of a sample return mission (origin of the sample is well known) (4) by analysing something found on Earth's surface or in the atmosphere (e.g. meteorite and atmospheric sample) (3) by a manned mission, in situ, on another celestial body (2) by a surface robot, in situ, on another celestial body (1) by remote sensing from the surface of the Earth or from satellites, flybys, etc.
Distance	(4) zero distance (on Earth) (3) inside the orbit of Jupiter (in situ research more easily possible) (2) on or outside the orbit of Jupiter, but in the Solar System (in situ research possible, but difficult) (1) beyond the Solar System (in situ research impossible)
Reliability	(5) certain or highly reliable (4) probably real (3) testable, needs further evidence (2) controversial, but not rejectable (1) probably not real (0) obviously fake or fraudulent

Scores

Quality	Score
Type
Nature
Method
Distance
Total

Overall	Score
Quality
Reliability
Total Score

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