Exoplanets

7.

Habitability and Astrobiology

7.1.

Habitable Zone Concept

7.1.1.

Classical Habitable Zone Definition

7.1.1.1.

Liquid Water Stability

7.1.1.2.

Stellar Luminosity Dependence

7.1.1.3.

Inner and Outer Boundaries

7.1.2.

Habitable Zones Around Different Stars

7.1.2.1.

Main Sequence Star Types

7.1.2.2.

M Dwarf Considerations

7.1.2.3.

Evolved Star Phases

7.1.2.4.

Binary Star Systems

7.1.3.

Extended Habitability Concepts

7.1.3.1.

Subsurface Habitability

7.1.3.2.

Atmospheric Greenhouse Effects

7.1.3.3.

7.1.3.4.

Galactic Habitable Zone

7.2.

Planetary Habitability Factors

7.2.1.

Atmospheric Requirements

7.2.1.1.

Atmospheric Retention

7.2.1.2.

Greenhouse Gas Regulation

7.2.1.3.

Oxygen and Ozone

7.2.1.4.

Atmospheric Pressure

7.2.2.

Magnetic Field Protection

7.2.2.1.

Dynamo Generation

7.2.2.2.

Stellar Wind Shielding

7.2.2.3.

Atmospheric Loss Prevention

7.2.3.

Geological Activity

7.2.3.1.

Plate Tectonics

7.2.3.2.

Volcanic Outgassing

7.2.3.3.

7.2.3.4.

Surface Renewal

7.2.4.

Orbital and Rotational Factors

7.2.4.1.

Orbital Stability

7.2.4.2.

Eccentricity Effects

7.2.4.3.

Obliquity Variations

7.2.4.4.

Tidal Locking Considerations

7.3.

Biosignature Detection

7.3.1.

Atmospheric Biosignatures

7.3.1.1.

Oxygen and Ozone

7.3.1.2.

7.3.1.3.

7.3.1.4.

7.3.1.5.

Dimethyl Sulfide

7.3.2.

Biosignature Combinations

7.3.2.1.

Disequilibrium Chemistry

7.3.2.2.

Contextual Analysis

7.3.2.3.

Seasonal Variations

7.3.3.

False Positive Scenarios

7.3.3.1.

Abiotic Oxygen Production

7.3.3.2.

Geological Methane Sources

7.3.3.3.

Photochemical Processes

7.3.4.

Surface Biosignatures

7.3.4.1.

Vegetation Red Edge

7.3.4.2.

Seasonal Color Changes

7.3.4.3.

Polarization Signatures

7.3.5.

Technosignatures

7.3.5.1.

Artificial Light

7.3.5.2.

Industrial Pollutants

7.3.5.3.

7.3.5.4.

7.4.

Notable Potentially Habitable Worlds

7.4.1.

Proxima Centauri b

7.4.1.1.

Discovery and Confirmation

7.4.1.2.

Habitability Assessment

7.4.1.3.

Atmospheric Modeling

7.4.1.4.

Observational Prospects

7.4.2.

TRAPPIST-1 System

7.4.2.1.

System Architecture

7.4.2.2.

Multiple Habitable Zone Planets

7.4.2.3.

Atmospheric Characterization Efforts

7.4.2.4.

Tidal Locking Implications

7.4.3.

7.4.3.1.

Recent Discovery

7.4.3.2.

Habitable Zone Location

7.4.3.3.

Follow-up Potential

7.4.4.

7.4.4.1.

Atmospheric Water Detection

7.4.4.2.

Habitability Debate

7.4.4.3.

Sub-Neptune Challenges

Previous

6. Planet Formation and Evolution

Go to top

Next

8. Future Directions and Emerging Frontiers