Short notes on Current Affairs 25.12.2025

ISRO Launches BlueBird Block-2 Satellite

Launch Details:

• Date & Time: 24/12/2025, 8:55 a.m. IST
• Launch Vehicle: LVM3 (Launch Vehicle Mark 3), also called Bahubali rocket
• Launch Site: Second launch pad, Satish Dhawan Space Centre, Sriharikota
• Mission Duration to Orbit: 15 minutes
• Payload: BlueBird Block-2 satellite (6,100 kg) – the heaviest payload ever launched by LVM3 from India

Mission Highlights:

• Largest Commercial LEO Satellite: BlueBird Block-2 is the largest commercial communication satellite deployed in Low Earth Orbit.
• First Dedicated U.S. Customer Launch: Developed by AST SpaceMobile (U.S.), the mission provides direct-to-mobile satellite connectivity.
• Highly Accurate Orbit: Deviation less than 2 km, among the best globally for any launch vehicle.

Purpose of Satellite:

• Part of a global LEO constellation for space-based cellular broadband.
• Provides 4G & 5G connectivity directly to standard smartphones.
• Enables voice/video calls, texts, streaming, and data anywhere in the world.
• Features a 223 m² phased array, making it the largest commercial communications satellite in LEO.

Significance:

• Reliability: Demonstrates India’s growing capabilities in heavy-lift launches.
• Strategic Impact: Supports upcoming missions like Gaganyaan, strengthens commercial launch services, and boosts global partnerships.
• Historical Context: This was the 104th launch from Sriharikota and the 9th successful mission of LVM3.

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Keezhadi Settlements

Location and Background

• Keezhadi is an archaeological site along the Vaigai river in Sivaganga district, Tamil Nadu.
• Excavations have revealed brick walls, clay floors, drainage channels, pottery, and roof tiles, suggesting a planned, urban-like settlement.
• Tamil Sangam literature mentions busy towns and trade in this region, but firm dates were not available.

Research Objective

• Determine when the settlement was buried by flood sediments.
• Establish a timeline connecting structures, sediment layers, and river history.
• Understand environmental and climate events that may have influenced settlement patterns.

Methodology

• Researchers from Physical Research Laboratory (Ahmedabad) and Tamil Nadu Archaeology Department conducted the study.
• Used Optically Stimulated Luminescence (OSL) dating:
  • Quartz grains in sediment collect energy from natural radiation.
  • Exposure to sunlight “resets” the stored energy.
  • Measuring luminescence in the lab provides the burial age of the sediment.
• Collected four sediment samples from two excavation pits (KDI-1 and KDI-2) at different depths.
• Carefully handled samples to avoid sunlight exposure and removed contaminants.
• Measured natural radioactivity of sediments to calculate dose rates and burial ages.

Findings

• Sediment layers showed coarse sand at the bottom and finer silts/clays above, consistent with flood deposition.
• Brick structures were buried under 1,155 years ago, around the 10th century CE.
• Ages from different layers:
  • KDI-1: 80 cm → 670 years, 150 cm → 1,170 years
  • KDI-2: 290 cm → 940 years, 380 cm → 1,140 years
• Flood deposits may have caused abandonment or relocation of the settlement.
• Presence of canals of different widths suggests planned water management, possibly for freshwater and wastewater.

Climate and Environmental Context

• Late Holocene (last 5,000 years) had fluctuating wet and dry periods in South India.
• Rivers, including Vaigai, shifted courses over time.
• Floods and channel changes could damage or isolate settlements.
• Vaigai river today is several kilometres from Keezhadi, supporting the idea of historical river shifts.

Significance

• OSL dating provides timeline for sediment deposition, not construction.
• Helps separate human habitation period from natural burial events.
• Guides future excavation: older layers may be better preserved in some areas.
• Demonstrates the value of combining archaeology with geoscience to understand past human-environment interactions.
• Confirms that flooding shaped settlement patterns in Tamil Nadu around a millennium ago.

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Constitution of India in the Santhali language

Event Overview

• The President of India, Smt. Droupadi Murmu, released the Constitution of India in the Santhali language.
• The event was held at Rashtrapati Bhavan on December 25, 2025.
• The Constitution has been published in Ol Chiki script, the traditional script of the Santhali language.

Key Statements by the President

• The President described the occasion as a moment of pride and joy for the Santhali community.
• She emphasized that the availability of the Constitution in Santhali will:
  • Enable Santhali speakers to read and understand the Constitution in their mother tongue
  • Strengthen constitutional awareness and inclusion among tribal communities
• She highlighted that 2025 marks the centenary of the Ol Chiki script.
• The President appreciated the Union Ministry of Law and Justice for completing this initiative during the script’s centenary year.

Constitutional and Legal Significance

• The Santhali language was included in the Eighth Schedule of the Constitution through the 92nd Constitutional Amendment Act, 2003.
• Publishing the Constitution in Santhali reinforces:
  • Linguistic equality
  • Cultural recognition of tribal languages
  • The spirit of inclusive democracy

Cultural and Historical Importance

• Santhali is described as one of the most ancient living languages of India.
• It is spoken widely by tribal communities in:
  • Jharkhand
  • Odisha
  • West Bengal
  • Bihar
• The use of Ol Chiki script preserves and promotes indigenous knowledge systems and identity.

Overall Analysis

• The initiative represents a major step toward social inclusion and empowerment of tribal communities.
• It aligns with constitutional values of:
  • Justice
  • Equality
  • Respect for cultural diversity
• The release strengthens the idea that the Constitution belongs to all citizens, regardless of language or region.

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Indian Railways Rationalises Fare Structure

Policy Change & Effective Date

• Indian Railways has rationalised its passenger fare structure.
• The revised fares apply to tickets booked on or after 26 December 2025.
• Tickets booked before this date remain unaffected, even if travel occurs later.

Objective of Fare Rationalisation

• To strike a balance between affordability for passengers and financial sustainability of railway operations.
• Emphasis on minimal impact to short-distance and daily commuters.

Services Unaffected by Fare Changes

• Suburban train services
• All Season Tickets (suburban and non-suburban)
• Reservation fees
• Superfast surcharge
• Other ancillary charges
• GST rules and fare rounding norms

Ordinary Non-AC (Non-Suburban) Trains

• Second Class Ordinary
  • No fare increase for journeys up to 215 km.
  • Graded, flat increases for longer distances:
    • ₹5 for 216–750 km
    • ₹10 for 751–1250 km
    • ₹15 for 1251–1750 km
    • ₹20 for 1751–2250 km
  • Structure protects short-distance and frequent travelers.
• Sleeper Class Ordinary & First Class Ordinary
  • Uniform fare increase of 1 paise per kilometre.
  • Applied only to non-suburban journeys.
  • Ensures gradual and limited fare revision.

Mail/Express Trains (Non-AC and AC Classes)

• Uniform fare increase of 2 paise per kilometre across all classes.
• Applicable to:
  • Sleeper Class
  • First Class
  • AC Chair Car
  • AC 3-Tier
  • AC 2-Tier
  • AC First Class
• Example impact:
  • A 500 km journey in non-AC Mail/Express trains costs approximately ₹10 extra, indicating a modest increase.

Premium and Special Train Services

• Basic fares revised in line with approved class-wise increases.
• Covers major services including:
  • Rajdhani, Shatabdi, Duronto
  • Vande Bharat, Tejas
  • Humsafar, Amrit Bharat
  • Garib Rath, Antyodaya
  • Jan Shatabdi, Gatimaan
  • Mahamana, Yuva Express
  • Namo Bharat Rapid Rail
• Ordinary non-suburban services included.
• AC MEMU/DEMU services excluded where applicable.
• Revisions are uniform and calibrated across classes.

Implementation & Transparency

• Fare lists displayed at stations will be updated from 26 December 2025.
• Changes apply strictly as per booking date, ensuring fairness and clarity.

Overall Assessment

• Fare increases are modest, graded, and distance-based.
• Strong focus on protecting daily commuters and short-distance passengers.
• Policy reflects a balanced, passenger-sensitive approach while supporting long-term operational sustainability of Indian Railways.

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