Indian astronomers, including researchers from IIT Kanpur, have developed a new technique to measure distances in space using pulsars by combining dispersion measure and scatter broadening.
What are Pulsars?
Pulsars are dense, rapidly spinning neutron stars
Emit regular radio wave pulses
Act as cosmic clocks due to highly stable rotation
Used to detect gravitational waves and deep space phenomena
New Measurement Method
Scientists combined two effects:
1. Dispersion Measure (DM)
Radio waves pass through ionised gas
Lower frequency waves arrive later
Used to estimate distance
2. Scatter Broadening
Plasma irregularities scatter signals
Signals follow multiple paths
Causes signal stretching
New Approach
Combined Dispersion + Scattering
Improves accuracy of distance measurement
Study Details
Observed 10 pulsars
Region studied: Gum Nebula
Found Vela Pulsar located behind nebula
Developed improved electron distribution model
Significance
More accurate deep space distance measurement
No strict distance limitation
Can be used for Fast Radio Bursts (FRBs)
Improves understanding of interstellar medium
[2023] Consider the following pairs: Objects in space : Description 1 Cepheids : Giant clouds of dust and gas in space 2 Nebulae : Stars which brighten and dim periodically 3 Pulsars : Neutron stars that are formed when massive stars run out of fuel and collapse How many of the above pairs are correctly matched? (a) Only one (b) Only two (c) All three (d) None
Non fossil capacity: Nearly 50% installed capacity
But electricity generation: Only 25%
Reason:Solar and wind are intermittent
[2025] Consider the following statements about ‘PM Surya Ghar Muft Bijli Yojana’: I. It targets installation of one crore solar rooftop panels in the residential sector. II. The Ministry of New and Renewable Energy aims to impart training on installation, operation, maintenance and repairs of solar rooftop systems at grassroot levels. III. It aims to create more than three lakhs skilled manpower through fresh skilling and up-skilling, under scheme component of capacity building. Select the correct answer using the code given below: (a) I and II only (b) I and III only (c) II and III only (d) I, II and III
India has withdrawn its bid to host COP 33 in 2028, according to reports. India had earlier expressed interest at COP 28 (Dubai, 2023).
Key Points
COP 33 scheduled for 2028
India withdrew after review of commitments
No official government statement yet
South Korea now only country interested
COP Hosting Rotation
COP hosting rotates among 5 UN regional groups:
African States
Asia Pacific States
Eastern European States
Latin America & Caribbean
Western Europe & Others
India belongs to Asia Pacific group.
Upcoming COPs
COP 30: Brazil
COP 31: Turkey & Australia
COP 32 (2027): Ethiopia
COP 33 (2028): To be decided
India’s COP Hosting History
India hosted COP 8 (2002)
Only time India hosted COP
India’s Climate Commitments (Updated NDCs)
By 2035, India aims to:
60% electricity from non fossil sources
Reduce emissions intensity by 47%
Increase carbon sink by 3.5 to 4 billion tonnes CO₂
What is COP
COP = Conference of Parties
Annual UN climate summit
Under UNFCCC
Discuss climate change policies
[2025] Consider the following statements: Statement I: At the 28th United Nations Climate Change Conference (COP28), India refrained from signing the ‘Declaration on Climate and Health’. Statement II: The COP 28 Declaration on Climate and Health is a binding declaration; and if signed, it becomes mandatory to decarbonize health sector. Statement III: If India’s health sector is decarbonized, the resilience of its healthcare system may be compromised. Which one of the following is correct in respect of the above statements? (a) Both Statement II and Statement III are correct and both of them explain Statement I (b) Both Statement II and Statement III are correct but only one of the them explains Statement I (c) Only one of the Statements II and III is correct and that explains Statement I (d) Neither Statement II nor Statement III is correct
The Indian Space Situational Assessment Report (ISSAR) 2025 revealed 315 global space launches in 2025, placing 4,651 objects into orbit.
Global Space Activity 2025
Total launches: 315
Objects placed in orbit: 4,651
Objects re entered atmosphere: 1,911
Net growth in space objects: 74.5%
India’s Space Assets
Satellites
Total Indian satellites in orbit: 86
Operational: 27
Defunct: 23
Decayed: 36
Indian satellites launched in 2025: 8
Rocket Bodies
4 rocket bodies placed in orbit
12 Indian objects re entered atmosphere
[2022] Which one of the following statements best reflects the idea behind the “Fractional Orbital Bombardment System” often talked about in media? (a) A hypersonic missile is launched into space to counter the asteroid approaching the Earth and explode it in space. (b) A spacecraft lands on another planet after making several orbital motions. (c) A missile is put into a stable orbit around the Earth and deorbits over a target on the Earth. (d) A spacecraft moves along a comet with the same speed and places a probe on its surface.
The Archaeological Survey of India (ASI) discovered a 1,500 year old stepped reservoir on Elephanta Island near Mumbai, indicating advanced water management and maritime trade.
Key Findings
Age: ~1,500 years old
Shape: T shaped stepped reservoir
Size:
Length: 14.7 metres
Width: 6.7 to 10.8 metres
Depth: 5 metres excavated
20 steps discovered so far
Why Reservoir Was Built
Elephanta Island is rocky
Rainwater quickly flows into sea
Reservoir helped:
Store rainwater
Ensure water supply
Shows advanced ancient engineering.
Other Discoveries
Excavation yielded:
Brick structure (possibly dyeing vat)
Terracotta figurines
Glass and stone bangles
Carnelian and quartz beads
Storage pots
Stone anchors
Evidence of Maritime Trade
3,000 amphorae sherds from Mediterranean
Torpedo jars from West Asia and Mesopotamia
Used to store:
Wine
Oil
Fish sauce
Shows trade with Rome and West Asia.
Coins Discovered
60 coins found
Copper coins of Kalachuri ruler Krishnaraja
Period: 6th century CE
About Elephanta Island
Located near Mumbai coast
Known for Elephanta Caves
Dedicated to Lord Shiva
Period: 5th century CE
UNESCO World Heritage Site
[2021] Which one of the following ancient towns is well-known for its elaborate system of water harvesting and management by building a series of dams and channelizing water into connected reservoirs? (a) Dholavira (b) Kalibangan (c) Rakhigarhi (d) Ropar
PYQ Relevance[UPSC 2024] What changes has the Union Government recently introduced in the domain of Centre-State relations? Suggest measures to strengthen federalism.Linkage: Delimitation based on population directly affects inter-state power balance, raising concerns of northern dominance and southern marginalisation. The article links delimitation with federal tensions, making it central to debates on cooperative vs competitive federalism.
Mentor’s Comment
The Constitution (106th Amendment) Act, 2023 mandates 33% reservation for women in legislatures, linked to delimitation after the Census. Recent developments indicate a shift toward implementing delimitation using 2011 Census data alongside expansion of seats, raising concerns regarding representational equity, federal balance, and data validity.
Is the shift in sequencing of Census and delimitation constitutionally and politically significant?
Conducting delimitation without waiting for a fresh Census, marks a departure from the established constitutional and procedural norm of evidence-based representation. It raises concerns of institutional bypass, outdated data usage, and potential distortion of representational equity and federal balance.
Policy Shift: Alters sequencing by initiating delimitation before fresh Census data; departs from earlier stance linking both processes.
Electoral Timing: Aligns reform with upcoming elections; facilitates political mobilization, especially among women voters.
Institutional Deviation: Weakens precedent of evidence-based delimitation; raises concerns of procedural bypass.
Does population-based delimitation distort federal balance and representation?
Population-based delimitation is the process of redrawing electoral constituency boundaries and reallocating parliamentary/assembly seats to ensure each seat represents a similar number of people based on the latest census data. Its goal is to maintain democratic fairness (one person, one vote) by accounting for demographic shifts.
Population Criterion: Ensures seat allocation based on demographic weight; benefits high-growth northern states.
Regional Imbalance: Increases parliamentary strength of states like Uttar Pradesh and Bihar (~180 seats combined).
Southern Disadvantage: Reduces relative influence of southern states with stabilized population growth.
Federal Strain: Challenges balance between states; may disrupt cooperative federalism.
Can seat expansion mitigate representational inequity?
Seat Expansion: Proposes ~50% increase in Lok Sabha strength (543 to 816 seats).
Relative Share Preservation: Attempts to maintain proportional representation across states.
Absolute Advantage: Northern states still gain numerically larger representation despite uniform expansion.
Electoral Impact: Reinforces dominance under first-past-the-post system; numerical strength translates into electoral advantage.
Is reliance on 2011 Census data a structural limitation?
Outdated Data: Uses decade-old demographic profile despite ongoing Census process.
Demographic Shifts: Ignores urbanization, migration, COVID-19 impact on population patterns.
Misrepresentation Risk: Leads to inaccurate constituency boundaries and population ratios.
Policy Trade-off: Prioritizes speed of reform over accuracy of representation.
What are the implications of delimitation for women’s reservation?
Delayed Implementation: Reservation tied to delimitation; postpones actual political inclusion.
Rotation Mechanism: Lack of clarity on rotation of reserved constituencies affects continuity and accountability.
Sub-quota Demand: Triggers demand for OBC and minority sub-quotas within women’s reservation.
Electoral Disruption: Frequent rotation may weaken constituency development and political stability.
Does delimitation represent a structural redesign of Indian democracy?
Electoral Reconfiguration: Redraws constituency boundaries; reshapes political geography.
Power Redistribution: Alters inter-state and intra-state political power dynamics.
Social Representation: Changes composition of legislatures across gender, caste, and region.
Long-term Impact: Marks one of the most significant shifts in representation since early decades of the Republic.
Conclusion
Delimitation, coupled with women’s reservation, represents a structural transformation of India’s electoral system. Its implementation without updated data risks distorting representation and federal balance. A calibrated, data-driven, and consensus-based approach is essential to preserve democratic legitimacy.
India has updated its Nationally Determined Contributions (NDCs) under the Paris Agreement, signalling continuity in climate ambition while exposing tensions between developmental needs and decarbonisation pressures. The revision raises critical questions on feasibility, equity, and financing, especially for a lower-middle-income economy navigating industrial expansion.
What are the key enhancements in India’s updated NDCs?
Emission Intensity Reduction: Targets reduction of 47% below 2005 levels by 2030, increasing ambition beyond earlier 45%.
Non-Fossil Capacity Expansion: Ensures 50% installed electric capacity from non-fossil sources, strengthening renewable transition.
Carbon Sink Expansion: Enhances forest and tree cover to create 2.5-3 billion tonnes CO₂ equivalent sink.
Continuity in Policy: Retains alignment with earlier commitments while incrementally increasing ambition.
Why are India’s climate commitments structurally constrained?
Developmental Status: Reflects lower-middle-income economy, limiting fiscal and technological capacity.
Energy Demand Growth: Ensures rising demand due to industrial expansion and urbanisation.
Per Capita Emissions: Remains one-third of global average, reinforcing equity argument.
Historical Responsibility: Highlights minimal contribution compared to developed countries.
What are the major implementation challenges in achieving NDC targets?
Storage Constraints: Limits renewable scalability due to lack of battery storage capacity.
Grid Integration Issues: Creates challenges in balancing intermittent sources like solar and wind.
Transmission Bottlenecks: Restricts evacuation of renewable energy from generation sites.
Operational Costs: Increases costs due to backup fossil-based power for intermittency.
Does renewable energy expansion fully address India’s climate goals?
Intermittency Challenge: Reduces reliability due to solar/wind variability.
Curtailment Risk: Leads to underutilisation of installed RE capacity.
Cost-effectiveness Debate: Questions viability when storage and backup costs are included.
Hydropower Constraints: Limits expansion due to environmental and regulatory challenges.
How does global climate ambition interact with India’s development needs?
1.5°C Target Pressure: Requires deeper cuts beyond current NDC trajectory.
Equity Principle: Demands consideration of common but differentiated responsibilities (CBDR).
Industrial Growth Needs: Necessitates expansion in manufacturing and infrastructure sectors.
Urbanisation Demand: Increases energy consumption due to rising living standards.
What are the financial and institutional gaps in India’s climate strategy?
Climate Finance Deficit: Limits implementation due to lack of adequate global funding.
Technology Access Barriers: Restricts adoption of advanced clean technologies.
Institutional Coordination: Creates challenges across sectors like energy, transport, and industry.
Global Cooperation Gaps: Weakens support due to inadequate commitments by developed nations.
Should India increase its climate ambition further?
Feasibility Concerns: Questions practicality given structural constraints.
Cost Implications: Raises economic burden without assured external support.
Strategic Positioning: Suggests calibrated approach using “national circumstances” principle.
Global Inequity: Highlights disproportionate burden-sharing by developing countries.
Conclusion
India’s updated NDCs reflect a calibrated balance between climate responsibility and developmental priorities. While ambition has increased, structural constraints in finance, technology, and energy systems necessitate a cautious approach. Future climate action must align with equity, global support, and domestic growth imperatives.
PYQ Relevance
[UPSC 2022] Discuss global warming and mention its effects on the global climate. Explain the control measures to bring down the level of greenhouse gases which cause global warming, in the light of the Kyoto Protocol, 1997.
Linkage: The question directly links to India’s updated NDCs as both focus on reducing greenhouse gas emissions through global commitments and national targets under UNFCCC frameworks. It is relevant as it helps analyze how India balances emission reduction obligations (Kyoto/Paris) with developmental priorities, as highlighted in the article.
India’s Kalpakkam Fast Breeder Reactor has achieved criticality, marking the first time the country has operationalized the second stage of its three-stage nuclear programme. This is significant because it enables production of more fuel than consumed, overcoming uranium scarcity and unlocking India’s vast thorium reserves.
What is the significance of achieving ‘criticality’ in a Fast Breeder Reactor?
Criticality Achievement: Ensures initiation of a self-sustaining nuclear fission chain reaction; marks transition from testing to operational stage.
Fuel Multiplication: Produces more fissile material (Pu-239) than consumed, unlike conventional reactors; enables long-term sustainability.
Strategic Breakthrough: Establishes India among a limited group of nations with operational breeder technology.
Cost Constraints: High capital costs and long gestation periods.
India’s Position: Becomes second country after Russia to have a commercial FBR.
How does this development accelerate the thorium-based third stage?
Fuel Conversion: Converts thorium (Th-232) into fissile U-233.
Inventory Build-Up: Ensures sufficient plutonium and U-233 for sustained thorium cycle.
Strategic Timeline: Reduces delay in transitioning to thorium reactors.
Example: FBR enables faster accumulation of fissile material required for advanced heavy water reactors (AHWRs).
Conclusion
The Kalpakkam breakthrough operationalizes a decades-old vision of self-reliant nuclear energy. It transforms India’s nuclear trajectory from resource-constrained to resource-optimized. Sustained investments, safety assurances, and technological scaling remain critical for full realization.
PYQ Relevance
[UPSC 2017] Give an account of the growth and development of nuclear science and technology in India. What is the advantage of the fast breeder reactor programme in India?
Linkage: The question directly tests India’s indigenous nuclear capability, including the three-stage programme. The Kalpakkam Fast Breeder Reactor achieving criticality provides a contemporary example to substantiate advantages of FBRs in ensuring fuel sustainability, thorium utilization, and long-term energy independence.
Police in Greater Noida rescued 16 Indian Softshell Turtles from smugglers. The species is protected under Schedule I of Wildlife Protection Act.
About Indian Softshell Turtle
Scientific Name: Nilssonia gangetica
Also called: Gangetic Softshell Turtle
Type: Freshwater turtle
Family: Trionychidae (soft shelled turtles)
Conservation Status
IUCN Status: Endangered
Wildlife Protection Act 1972: Schedule I
CITES: Appendix I
Habitat & Distribution
Found in river systems: Ganga, Indus, and Mahanadi
Countries: India, Pakistan, Nepal, and Bangladesh
Habitat: Deep rivers, Lakes, Canals, and Muddy riverbeds
Key Features
Leathery soft shell
Olive green colour
Long snorkel like nose
Size up to 94 cm
Omnivorous scavenger
Why Smuggled
Myth of 20 claws brings good luck
Used in illegal wildlife trade
False medicinal beliefs
[2017] In India, if a species of tortoise is declared protected under Schedule I of the Wildlife (Protection) Act, 1972, what does it imply? (a) It enjoys the same level of protection as the tiger. (b) It no longer exists in the wild, a few individuals are under captive protection; and now it is impossible to prevent its extinction. (c) It is endemic to a particular region of India. (d) Both (b) and (c) stated above are correct in this context.
The National Statistical Office (NSO) launched the first ever Annual Survey of Incorporated Services Sector Enterprises (ASISSE) for 2024–25.
What is ASISSE
New annual survey of incorporated services sector
Covers:
Companies under Companies Act 1956/2013
Limited Liability Partnerships (LLPs)
Conducted By
National Statistical Office (NSO)
Under Ministry of Statistics and Programme Implementation
Objectives
Create database of formal services sector
Fill data gap in services economy
Provide data for policymaking
Coverage
Sectors included: Trade, Transport, Hospitality, IT services, Education, Health, and Professional services
Key Features
Sample size: ~21 lakh enterprises
Data source: GSTN database
Coverage: All States and UTs
Digital data collection
Legal basis:
Collection of Statistics Act 2008
Jan Vishwas Act 2023
Why It is Important
Services sector contributes 50%+ of GDP
First annual data for formal services sector
Helps measure:
Employment
Growth
Investment
Related Surveys
ASI: Annual Survey of Industries (Manufacturing)
ASUSE: Unincorporated Sector Survey
ASISSE: Incorporated Services Sector
[2024] With reference to the sectors of the Indian economy, consider the following pairs: Economic activity : Sector 1 Storage of agricultural produce : Secondary 2 Dairy farm : Primary Mineral exploration : Tertiary 3 Weaving cloth : Secondary Select the correct answer using the code given below: (a) Only one pair (b) Only two pairs (c) Only three (d) All four
