biosignatures
Signs of life
Biosignatures are detectable indicators of life, past or present.
The term appears most often in astrobiology, where scientists search for biosignatures on other planets or moons—chemical compounds, atmospheric gases, or physical structures that suggest biological activity.
On Earth, fossils and certain mineral deposits count as biosignatures of ancient life.
The rover analyzed Martian soil samples for biosignatures.
Worlds orbiting other stars
- spectroscopyStudy of light-matter interaction
- astrochemistryStudy of cosmic substances
- extremophilesOrganisms surviving extreme conditions
- habitable zoneRegion allowing liquid water
SETI · Kepler · James Webb · Mars · Europa · Enceladus · Titan · panspermia
Organic compounds forming proteins
- nucleotidesDNA and RNA subunits
- DNAHereditary code molecule
- RNAGene expression molecule
- proteinsAmino acid polymers
enzymes · lipids · chlorophyll · biomolecules · organic molecules · peptides · carbohydrates · ATP
Layered sedimentary bacterial structures
- microfossilsMinute preserved organism remains
- fossilsPreserved ancient organism traces
- amberHardened ancient tree secretion
- trace fossilsPreserved signs of activity
petrification · morphology · paleontology · sediments · preservation · carbon isotopes · ancient life · Precambrian
Simplest alkane fuel
- oxygenElement eight, colorless gas
- ozoneTriatomic oxygen allotrope
- carbon dioxideRespiration byproduct, photosynthesis fuel
- phosphinePH₃ gas compound
water vapor · nitrous oxide · ammonia · hydrogen sulfide · disequilibrium · atmospheric gases · greenhouse gases · aerosols
Study of light-matter interaction
- telescopeInstrument magnifying faraway objects
- spectrometerMeasures electromagnetic radiation properties
- mass spectrometryMeasures ionic weight ratios
- chromatographyTechnique separating mixtures by differential migration
microscopy · remote sensing · sensors · calibration · resolution · signal-to-noise · false positives · baseline
exoplanets
Worlds orbiting other stars
- spectroscopyStudy of light-matter interaction
- astrochemistryStudy of cosmic substances
- extremophilesOrganisms surviving extreme conditions
habitable zone · SETI · Kepler · James Webb · Mars · Europa · Enceladus · Titan · panspermia · Drake equation
amino acids
Organic compounds forming proteins
- nucleotidesDNA and RNA subunits
- DNAHereditary code molecule
- RNAGene expression molecule
proteins · enzymes · lipids · chlorophyll · biomolecules · organic molecules · peptides · carbohydrates · ATP · cofactors
stromatolites
Layered sedimentary bacterial structures
- microfossilsMinute preserved organism remains
- fossilsPreserved ancient organism traces
- amberHardened ancient tree secretion
trace fossils · petrification · morphology · paleontology · sediments · preservation · carbon isotopes · ancient life · Precambrian
methane
Simplest alkane fuel
- oxygenElement eight, colorless gas
- ozoneTriatomic oxygen allotrope
- carbon dioxideRespiration byproduct, photosynthesis fuel
phosphine · water vapor · nitrous oxide · ammonia · hydrogen sulfide · disequilibrium · atmospheric gases · greenhouse gases · aerosols · outgassing
spectroscopy
Study of light-matter interaction
- telescopeInstrument magnifying faraway objects
- spectrometerMeasures electromagnetic radiation properties
- mass spectrometryMeasures ionic weight ratios
chromatography · microscopy · remote sensing · sensors · calibration · resolution · signal-to-noise · false positives · baseline · interferometry