TAG: GS 3: SCIENCE AND TECHNOLOGY
THE CONTEXT: NASA has announced the discovery of Gliese 12 b, a potentially habitable exoplanet located 40 light years from Earth.
EXPLANATION:
- This significant finding could provide crucial insights into the habitability of other planets across the galaxy.
Gliese 12 b
- Gliese 12 b is classified as a “super Earth exoplanet,” meaning it is nearly the same size as Earth or slightly smaller.
- It orbits its star, Gliese 12, every 12.8 days.
- The discovery was highlighted by a project assistant professor at the Astrobiology Center in Tokyo, who noted that Gliese 12 b is the nearest transiting, temperate, Earth-size world discovered to date.
- Gliese 12
- The planet orbits a cool red dwarf star named Gliese 12.
- This star is relatively small, being only about 27% of the Sun’s size and having approximately 60% of the Sun’s surface temperature.
- Due to these characteristics, red dwarf stars like Gliese 12 are considered ideal for the detection of Earth-size planets.
- Their smaller sizes and masses result in greater dimming during transits and more pronounced reflex motions, making planets easier to detect.
- While it remains unknown whether Gliese 12 b possesses an atmosphere, it is currently viewed as an “exo-Venus” due to its similar size and the energy it receives from its star.
- Assuming the planet lacks an atmosphere, NASA estimates its surface temperature to be around 107 degrees Fahrenheit.
- Despite this, the proximity to its star and the energy received suggest potential habitability conditions.
Red Dwarf Stars and Earth-Size Planets
- Red dwarf stars are considered key in the search for Earth-size planets.
- Their lower luminosities make it easier to determine if orbiting planets are habitable and capable of having liquid water on their surfaces.
- Gliese 12 b, receiving 1.6 times more energy from its star than Earth does from the Sun, represents a prime candidate for studying these conditions.
Importance of Gliese 12 b
- Gliese 12 b’s proximity to its star, at just 7% of the Earth-Sun distance, makes it an excellent target for studying the retention of atmospheres on Earth-size planets orbiting cool stars.
- Studying such planets is vital for advancing our understanding of planetary habitability across the galaxy.
Future Research and Transmission Spectroscopy
- Researchers plan to use transmission spectroscopy to study Gliese 12 b and similar planets.
- This technique involves observing starlight passing through a planet’s atmosphere during transit to determine its composition.
- A research astrophysicist at NASA’s Goddard Space Flight Center highlighted the need for more examples like Gliese 12 b to better understand the diversity of atmospheres and evolutionary outcomes for these planets.
- Current facilities are capable of studying only a few temperate planets similar to Earth that are both close enough and meet the criteria for such detailed analysis.
SOURCE: https://www.usatoday.com/story/news/nation/2024/05/28/nasa-exoplanet-discovery/73882055007/
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