NASA Discovers Potentially Habitable Exoplanet K2-18 b

NASA’s James Webb Space Telescope has made a groundbreaking discovery. The telescope detected an exoplanet named K2-18 b, located approximately 124 light years from Earth. This planet is larger than Earth and lies within the habitable zone of its star, K2-18. The habitable zone is a region where conditions may support liquid water, a vital ingredient for life as we know it.

Characteristics of K2-18 b

K2-18 b has a radius 2.6 times that of Earth and a mass 8.6 times greater. Its size raises questions about its habitability. Scientists believe it might possess a hydrogen-rich atmosphere. This atmosphere includes gases such as methane and carbon dioxide, which are often linked to biological processes.

Atmospheric Analysis

The James Webb Space Telescope conducted detailed analyses of K2-18 b’s atmosphere. Initial findings suggested the presence of dimethyl sulfide (DMS). On Earth, DMS is primarily produced by marine phytoplankton. The detection of DMS could indicate biological activity, heightening the possibility of life on K2-18 b.

Hycean Exoplanets

K2-18 b is classified as a ‘Hycean exoplanet.’ This term refers to planets that are likely covered by oceans and possess hydrogen-rich atmospheres. Researchers are now considering these larger worlds as potential habitats for life, expanding the search beyond smaller, rocky planets.

Research Significance

The research team, led by astronomer Nikku Madhusudhan from the University of Cambridge, emphasised the importance of diverse habitable environments. Traditional searches for extraterrestrial life have primarily focused on Earth-like planets. The discovery of K2-18 b puts stress on the need to explore how larger exoplanets might support life.

Future Investigations

NASA has committed observational time to further investigate K2-18 b. The Webb telescope dedicated eight hours to confirm the presence of DMS in the planet’s atmosphere. The ultimate goal of this research is to identify life on a habitable exoplanet, which could reshape our understanding of our place in the universe.

Challenges of Habitability

Despite the promising signs, K2-18 b’s large size poses challenges for habitability. The planet may have a high-pressure ice mantle or excessively hot oceans. These factors could render it inhospitable to life as we know it.

The Search for Life

The ongoing investigations into K2-18 b highlight a very important moment in the search for extraterrestrial life. The findings may offer crucial vital information about how life could exist in environments previously considered unsuitable.

Conclusion

The discovery of K2-18 b opens new avenues for astronomical research. It challenges existing paradigms about where life might thrive in the universe.

Questions for UPSC:

1. Critically analyse the significance of detecting dimethyl sulfide in the atmosphere of K2-18 b.
2. Explain the concept of Hycean exoplanets and their relevance in the search for extraterrestrial life.
3. What are the implications of discovering life on an exoplanet like K2-18 b? Comment on the potential impact on human understanding of life in the universe.
4. What factors determine the habitability of an exoplanet? Discuss with suitable examples.

Answer Hints:

1. Critically analyse the significance of detecting dimethyl sulfide in the atmosphere of K2-18 b.

1. DMS is primarily produced by biological processes on Earth, mainly by marine phytoplankton.
2. The detection of DMS suggests potential biological activity on K2-18 b.
3. It raises the possibility of life existing in environments previously considered uninhabitable.
4. Finding DMS could indicate a complex ecosystem, enhancing the significance of K2-18 b as a target for further study.
5. This discovery challenges traditional views on where life can exist, expanding the search for extraterrestrial life.

2. Explain the concept of Hycean exoplanets and their relevance in the search for extraterrestrial life.

1. Hycean exoplanets are characterized by being covered in oceans and having hydrogen-rich atmospheres.
2. They may offer conditions suitable for life, similar to Earth, but in a different form.
3. K2-18 b is a prime example of a Hycean exoplanet, expanding the criteria for habitability.
4. Research on these planets can reveal diverse environments where life might exist, beyond rocky planets.
5. Hycean worlds could host unique biological processes, providing vital information about life’s adaptability.

3. What are the implications of discovering life on an exoplanet like K2-18 b? Comment on the potential impact on human understanding of life in the universe.

1. Discovery of life would validate theories about life’s existence beyond Earth.
2. It could reshape our understanding of biology and the conditions necessary for life.
3. The finding would prompt a reevaluation of the search for life in diverse environments.
4. It may lead to technological advancements in space exploration and astrobiology.
5. Such a discovery could encourage philosophical and existential discussions about humanity’s place in the universe.

4. What factors determine the habitability of an exoplanet? Discuss with suitable examples.

1. Distance from the star (habitable zone) is crucial for maintaining liquid water, as seen with K2-18 b.
2. Atmospheric composition affects temperature and pressure; a hydrogen-rich atmosphere may support life.
3. Planet size and mass influence gravity and geological activity, impacting habitability.
4. Presence of water is essential; planets like K2-18 b may have oceans beneath their atmospheres.
5. Examples like Mars and Venus illustrate how varying conditions can lead to different habitability outcomes.