29 December 2024

• Science: NASA's Parker Solar Probe completed its closest-ever approach to the Sun on 24 December 2024, passing within 6.1 million km at a record speed of 692,000 km/h.
• Defence: The Indian Navy's Air Independent Propulsion (AIP) upgrade programme for Scorpene-class submarines progressed, with a 2,867 crore rupee contract advancing.
• International: The H-1B visa programme debate intensified in the US following policy proposals to raise or cap skilled worker quotas.
• Environment: A report on Olive Ridley turtle nesting at Gahirmatha, Odisha, noted a record pre-season aggregation.

GS area: Science and Technology

NASA's Parker Solar Probe completed its 22nd perihelion pass on 24 December 2024, achieving the closest approach to the Sun in human history.

• Distance: 6.1 million km from the Sun's surface (photosphere). For context, Mercury, the innermost planet, orbits at about 57.9 million km.
• Speed: 692,000 km/h (about 430,000 miles per hour), the fastest speed ever achieved by a human-made object.
• Launch: Launched 12 August 2018 from Cape Canaveral, Florida, aboard a Delta IV Heavy rocket.
• Mission objectives:
  • Understand why the solar corona (outer atmosphere) is hotter than the visible surface (photosphere). The corona reaches millions of degrees, while the photosphere is about 5,500 degrees Celsius.
  • Study the origin and acceleration of the solar wind (stream of charged particles from the Sun).
  • Investigate solar energetic particle events that pose radiation risks to satellites and astronauts.
• Heat shield: An 11.4-cm carbon-carbon composite heat shield (called the Thermal Protection System) keeps instruments below 29 degrees Celsius despite temperatures exceeding 1,400 degrees Celsius on the shield's outer surface.
• Gravity assist: The probe uses Venus flybys to gradually tighten its orbit around the Sun.
• Significance for India: Solar particle events affect ISRO's satellite operations and Gaganyaan. Indian space weather forecasting capabilities are being developed under ISRO's Aditya-L1 mission (launched September 2023).

Static linkage: Science and technology (space science, solar physics, NASA, Aditya-L1).

GS area: Defence, Science and Technology

The Indian Navy's programme to upgrade Scorpene-class submarines with Air Independent Propulsion (AIP) technology moved forward in December 2024.

• AIP definition: Air Independent Propulsion allows a submarine to power its electric motors without surfacing to recharge batteries. Conventional diesel-electric submarines must snorkel (raise a mast to the surface) to run diesel generators and recharge.
• Technology types: Proton Exchange Membrane (PEM) fuel cells (used by Germany's Type 212 submarine), Stirling engine (used by Japan's Soryu class), closed-cycle diesel, liquid metal reactor (nuclear submarines do not need AIP).
• India's programme: DRDO's Naval Materials Research Laboratory (NMRL) developed an indigenous PEM fuel cell-based AIP system. The system will extend underwater endurance from a few days to two to three weeks.
• Scorpene class in India: Six Kalvari-class submarines (Scorpene design) built by Mazagon Dock Shipbuilders, Mumbai. All commissioned by 2023-24.
• Contract: 2,867 crore rupees for AIP retrofitting of the first batch of Scorpene submarines.
• Strategic significance: AIP submarines are harder to detect than conventional submarines due to reduced noise from not needing to snorkel. Important for anti-submarine warfare (ASW) operations in the Indian Ocean.

Static linkage: Defence (naval technology, submarines, DRDO, indigenisation, Make in India).

GS area: International Relations, Economy

The H-1B visa programme attracted significant attention as US policy debates intensified in December 2024.

• H-1B visa: US non-immigrant visa category for skilled workers in "specialty occupations" requiring at least a bachelor's degree. Valid for three years, extendable to six, and further extendable if a green card application is pending.
• Annual cap: 65,000 regular H-1B visas plus 20,000 additional visas for holders of US master's degrees from accredited institutions. Total cap: 85,000 per year. Demand far exceeds supply; allocation is by lottery since 2007.
• India's share: Indian applicants (primarily IT professionals and engineers) receive about 70-75 per cent of all H-1B visas granted annually.
• Major Indian employers: Infosys, TCS, Wipro, HCL among the top applicants. US companies like Amazon, Google, Microsoft, Meta also file heavily.
• 2024-25 policy debate: Incoming Trump administration officials debated raising or removing the cap versus restricting H-1B visas to protect American workers.
• India's bilateral interest: India has consistently advocated for an increase in the H-1B cap in trade negotiations. Remittances from Indian H-1B workers contribute to India's foreign exchange earnings.

Static linkage: International relations (India-US, immigration policy, skilled labour), economy (remittances).

GS area: Environment

A record aggregation of Olive Ridley sea turtles was reported at Gahirmatha Marine Wildlife Sanctuary, Odisha, in December 2024, ahead of the mass nesting season.

• Olive Ridley sea turtle: Lepidochelys olivacea. Smallest of all sea turtles. Named for their olive-coloured carapace.
• Gahirmatha: Located at the mouth of the Brahmani river in the Bhitarkanika Wildlife Sanctuary, Odisha. Recognised as the world's largest mass nesting site for Olive Ridley turtles.
• Arribada: Mass synchronous nesting behaviour. Tens of thousands of females come ashore on the same nights to lay eggs. Gahirmatha sees the largest arribada events globally.
• IUCN status: Vulnerable.
• CITES: Appendix I.
• Wildlife Protection Act: Schedule I.
• Threats: Trawling nets (turtles drown as by-catch), light pollution (disorientation), coastal development, boat strikes.
• TED requirement: Turtle Excluder Devices (TEDs) are mandatory on trawlers operating near Gahirmatha during nesting season.
• Other Odisha nesting sites: Rushikulya, Devi river mouth.

Static linkage: Environment (sea turtles, Gahirmatha, arribada, marine conservation, Bhitarkanika).

GS area: Governance, Science and Technology

The Ministry of Electronics and Information Technology released a year-end review of India's Digital Public Infrastructure (DPI) achievements.

• Aadhaar: Over 138 crore unique digital identities issued.
• UPI: Over 24,000 crore transactions processed in 2024. Extended to the UAE, Singapore, Bhutan, Nepal, France and Mauritius.
• DigiLocker: Over 62 crore registered users. Hosts more than 7.3 billion documents (driving licences, vehicle registration, academic certificates).
• India Stack: The collective term for India's DPI layer: Aadhaar (identity), eKYC (verification), UPI (payments), DigiLocker (documents), DEPA (data exchange, consent-based).
• NPCI: National Payments Corporation of India. Operator of UPI, RuPay, IMPS, NACH. Set up as a not-for-profit entity by RBI and the Indian Banks' Association.
• Global recognition: The G20 New Delhi Declaration (2023) endorsed the India Stack model for other developing nations.

Static linkage: Governance (DPI, Aadhaar, UPI, India Stack, digital economy).

GS area: Geography, Environment

• Location: Kendrapara district, Odisha coast. Between the Mahanadi delta in the north and the Dhamra river in the south.
• Area: 1,435 sq km. Declared a Marine Wildlife Sanctuary in 1997 under the Wildlife Protection Act.
• Bhitarkanika connection: The sanctuary abuts the Bhitarkanika National Park (mangroves), India's second-largest mangrove ecosystem after the Sundarbans.
• Waterways: The Gahirmatha beach system is at the confluence of the Brahmani and Baitarani rivers with the Bay of Bengal.
• Other biodiversity: Saltwater crocodiles, water monitor lizards, kingfishers, sea eagles and several shorebird species.

Static linkage: Geography (Odisha coast, Bhitarkanika, Mahanadi delta, mangroves).

• SIMBEX 31: The 31st India-Singapore Bilateral Maritime Exercise was held in the South China Sea in late December 2024, focusing on anti-submarine warfare, surface warfare, air defence drills and humanitarian scenarios.
• Kisan Credit Card saturation: The government aimed to saturate Kisan Credit Cards (KCC) to all eligible farmers. KCC provides revolving credit at 4 per cent interest (2 per cent after subvention for timely repayment) for up to 3 lakh rupees without collateral.