Scientists have found evidence why some planets are shrinking (GS Paper 3, Science and Technology)
Why in news?
- Recently, the using data from NASA's retired Kepler Space Telescope have found evidence suggesting why some exoplanets are shrinking in size.
- Exoplanets are planetary bodies that have been discovered outside the solar system. So far, over 5000 exoplanets have been detected.
Details:
- The research indicates that the cores of certain sub-Neptune planets may be pushing their atmospheres away, leading to a reduction in planet size.
- The universe is home to an array of exoplanets, ranging from small, rocky worlds to massive gas giants. However, astronomers have identified a puzzling scarcity of planets with diameters between 1.5 and 2 times that of Earth, creating a "size gap" between rocky super-Earths and gaseous sub-Neptunes.
- This study suggests that this gap is not coincidental but rather the result of atmospheric loss in less massive sub-Neptunes.
Key Highlights:
- Researchers propose that if a sub-Neptune lacks sufficient mass, its gravitational pull may be too weak to retain its atmosphere, causing it to diminish to super-Earth size.
- Two primary mechanisms are thought to drive this atmospheric loss: core-powered mass loss and photoevaporation. The new evidence supports the former, where radiation from a planet's hot core gradually forces the atmosphere outwards.
- Conversely, photoevaporation occurs when a star's intense radiation strips away a planet's atmosphere, likened to a hairdryer melting an ice cube.
- While photoevaporation is believed to happen within the first 100 million years of a planet's existence, core-powered mass loss likely occurs around the 1 billion-year mark.
Observations made:
- To investigate these theories, they examined data from the K2 mission, focusing on the relatively young star clusters Praesepe and Hyades.
- Their findings showed that nearly all stars in these clusters still possess sub-Neptune planets, suggesting that their atmospheres have not been eroded by photoevaporation. This observation points to core-powered mass loss as the more plausible explanation for the observed size gap.
Way Forward:
- The study's implications extend beyond solving a cosmic puzzle; understanding the evolution of exoplanet atmospheres can provide insights into the potential habitability of distant worlds.
- The research is ongoing, and future studies will further test these theories.
UP, Bihar replace Kerala as top contributor of workforce to GCC countries
(GS Paper 3, Economy)
Why in news?
- There has been a significant pattern shift in migration of Indian workers to the six Gulf Cooperation Council (GCC) countries; Bahrain, Kuwait, Oman, Qatar, Saudi Arabia, and the United Arab Emirates with Kerala, typically the biggest contributor of blue-collar workers, seeing a 90 per cent drop.
- The vacuum so caused has been filled by Uttar Pradesh and Bihar, which have emerged as top contributors, shows a study by UAE-based organisation, Huntr.
Migration pattern:
- Overall, there has been a 50 per cent increase in migration of blue-collar Indian workers to the GCC countries in first seven months of 2023.
- The top five states by the number of workers sent to GCC, according to the Huntr study, have been Uttar Pradesh, Bihar, Kerala, West Bengal, and Tamil Nadu.
- The preferred destinations for labour migration remain Saudi Arabia, the UAE, Qatar, Kuwait, and Oman.
Profile of the migrating workforce:
- The workforce migrating to the GCC countries are typically aged 20-40 years, in the prime of their working age.
- The migrating workforce has been traditionally dominated by men, but there is a substantial increase in participation of women, especially in sectors such as hospitality.
- The migrant workers’ qualifications and educational backgrounds differ while there also are individuals with skills tailored for specific job roles, according to the study.
- Most of the migrant workers belong to low-income families with an aspiration to improve their financial situation with jobs in Dubai.
Challenges & Way Forward:
- The blue-collar workers often grapple with challenges such as financial and contractual issues, which collaborative efforts between India and the UAE are diligently addressing to ensure fair recruitment practices.
- Concurrently, the UAE government's initiatives enhance the legal rights and working conditions of blue-collar workers, while skill enhancement and career growth are actively supported through partnerships between Huntr and non-profit organisations.
