Source: DownToEarth

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Context

• Astronomers have identified a potentially habitable exoplanet, Gliese 12 b, situated approximately 40 light-years from Earth.

Details

• Initial Identification: NASA’s Transiting Exoplanet Survey Satellite (TESS) identified Gliese 12 b as a potential planet candidate.
• Validation: The European Space Agency’s CHaracterising ExOPlanet Satellite (CHEOPS) confirmed its status as an exoplanet.

Physical Characteristics

• Surface Temperature: Gliese 12 b has an average surface temperature of 42 degrees Celsius, which, while warmer than Earth's average of 15 degrees Celsius, is lower than most discovered exoplanets.
• Size: The planet is similar in size to Venus and slightly smaller than Earth.
• Orbital Details: It orbits an M dwarf star, Gliese 12, every 12.8 days. This star hosts seven planets, three of which are in the habitable zone where liquid water could exist.

Star Characteristics

• Type: Gliese 12 is an M dwarf star, known for being low-mass.
• Metallicity: The star is metal-poor, suggesting it might have weaker magnetic fields and more volcanism than Earth.
• Magnetic Activity: The star’s low magnetic activity implies a higher likelihood that Gliese 12 b could retain an atmosphere.

Scientific Significance

• Proximity: Gliese 12 b is one of the closest potentially habitable exoplanets discovered, making it a prime candidate for further study.
• Comparison to Earth and Venus: Studying this exoplanet could provide insights into the divergent evolutionary paths of Earth and Venus, particularly concerning water retention and greenhouse effects.

Future Research

• Atmospheric Analysis: Determining whether Gliese 12 b has an atmosphere and its composition is critical for assessing its habitability.
• Temperature Suitability: While 42 degrees Celsius is warm for humans, it could be suitable for other forms of life.
• Potential Greenhouse Effect: Investigations will seek to determine if the planet experiences a runaway greenhouse effect similar to Venus.
• James Webb Space Telescope (JWST): Gliese 12 b is a potential target for the JWST, which could detect atmospheric features. The research team is yet to submit a proposal for this target.

Sources:

DownToEarth

PRACTICE QUESTION Q.  Which of the following methods is commonly used to detect exoplanets? A) Direct imaging B) Radial velocity method C) Transit method D) All of the above Answer: D)