Why in the News?
Indore, already recognized as the cleanest city in India, has topped the list of million-plus population cities in the Swachh Vayu Survekshan 2025.
About Swachh Vayu Survekshan (SVS), 2025:
- Overview: Annual survey by the Ministry of Environment, Forest and Climate Change (MoEFCC) under the National Clean Air Programme (NCAP).
- Objective: Promotes healthy competition among cities and accelerates implementation of air quality measures.
- Coverage: Includes 130 cities, grouped into 3 categories: million-plus population, 3–10 lakh population, and under 3 lakh population.
- Parameters: Cities assessed on 8 factors such as road dust mitigation, solid waste management, vehicular emission control, industrial emission control, construction and demolition waste handling, public awareness, and particulate matter (PM10/PM2.5) reduction.
- Methodology: Uses a multi-tier evaluation focusing on both on-ground actions and measurable outcomes.
Key Findings of SVS, 2025:
- Top Performer: Indore ranked 1st among million-plus cities, regaining its position after slipping to 6th in 2024. It had also topped in 2023, while Lucknow topped the inaugural edition in 2022.
- Other Million-Plus Rankings: Jabalpur 2nd, Agra and Surat 3rd, Navi Mumbai 4th, Kanpur 5th, Bhopal 6th, Allahabad 7th, Chandigarh 8th, Ahmedabad–Pune–Nagpur 10th, Varanasi and Raipur 11th, Lucknow 15th, Hyderabad 22nd, Mumbai 25th, Jaipur 26th, Delhi 32nd, Bengaluru 36th, Kolkata 38th, Chennai 41st.
- 3–10 Lakh Cities: Amravati 1st, Jhansi and Moradabad joint 2nd, Alwar 3rd.
- Under-3 Lakh Cities: Dewas 1st, Parwanoo 2nd, Angul 3rd.
- Air Quality Data: Indore recorded PM10 at 83 μg/m³ in 2024–25, slightly higher than 82 μg/m³ in 2017–18. Cities like Chennai (58 μg/m³), Varanasi (59 μg/m³), Bengaluru (68 μg/m³), and Hyderabad (81 μg/m³) showed lower PM10 levels than Indore.
- Overall Trends: 103 of 130 cities reduced PM10 since 2017–18. 64 cities achieved a 20% reduction, while 25 cities achieved a 40% reduction. Only 22 cities met the national standard of ≤60 μg/m³, with Chennai the only metro (58 μg/m³). Among metros, Mumbai recorded the highest decline (44%), followed by Kolkata (37%), Hyderabad (26%), Bengaluru (26%), Delhi (15%), and Chennai (12%).
| [UPSC 2022] In the context of WHO Air Quality Guidelines, consider the following statements:
1. The 24-hour mean of PM 2.5 should not exceed 15 μg/m3 and annual mean of PM 2.5 should not exceed 5 μg/m3.
2. In a year, the highest levels of ozone pollution occur during the periods of inclement weather.
3. PM 10 can penetrate the long barrier and enter the bloodstream.
4. Excessive ozone in the air can trigger asthma.
Which of the statements given above are correct?
Options: (a) 1,3 and 4 (b) 1 and 4 only* (c) 2,3 and 4 (d) 1 and 2 only |
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Why in the News?
India now has a comprehensive regulatory framework for biostimulants, placing it among the few countries with such dedicated oversight.
What are Biostimulants?
- Definition: Under Fertilizer Control Order (FCO), 1985, Clause 20C, biostimulants are substances or micro-organisms that stimulate plant processes to improve nutrient uptake, growth, yield, crop quality, efficiency, and stress tolerance.
- Exclusion: They are not pesticides or plant growth regulators, which fall under the Insecticides Act, 1968.
- Categories (Schedule VI, FCO): Botanical extracts (including seaweed), protein hydrolysates and amino acids, vitamins, biochemicals, antioxidants, anti-transpirants, humic and fulvic acids, cell-free microbial products, and live micro-organisms (excluding biofertilizers/biopesticides).
Regulation Timeline:
- Before 2021: Nearly 30,000 unregulated products in Indian markets.
- Feb 2021: Included under FCO; provisional registration system (G3 certificates) introduced; about 8,000 products approved temporarily.
- Current Status: Only 146 products formally notified in Schedule VI.
Key Amendments (2021–2025):
- 2021: Biostimulants legally recognised under FCO.
- 2023–24: Provisional validity extended to avoid disruption.
- 2025:
- Live micro-organisms (excluding biofertilizers/biopesticides) added as a category.
- Pesticide residue limit raised from 0.01 ppm to 1 ppm.
- Stricter quality testing, labelling, and safety standards enforced.
- Provisional system discontinued.
Significance:
- Protects farmers from spurious/unproven products.
- Encourages validated indigenous products under Atmanirbhar Bharat.
- Establishes quality, safety, and labelling standards through Gazette notifications.
- Makes India one of the few countries with a dedicated Biostimulant law, balancing farmer welfare, environmental safety, innovation, and regulation.
| [UPSC 2013] Consider the following organisms:
1.Agaricus 2.Nostoc 3.Spirogyra
Which of the above is/are used as biofertilizer/biofertilizers?
Options: (a) 1 and 2 (b) 2 only* (c) 2 and 3 (d) 3 only |
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Why in the News?
An Indian Armed Forces contingent has departed for Mulino Training Ground, Nizhniy, Russia, to participate in Exercise ZAPAD 2025.
About Exercise ZAPAD:
- Meaning: “ZAPAD” means West in Russian; a series of large-scale joint strategic military drills led by Russia and Belarus.
- Origins: Started during the Soviet era with Zapad-77, Zapad-81, Zapad-84, reflecting Cold War dynamics.
- Post-Soviet Revival: Resumed with Zapad-99 (1999), partly as a response to NATO’s Yugoslavia operations.
- Frequency: Held about once every 4 years, with major editions in 2009, 2013, 2017, 2021, and 2025.
- Series Context: Forms part of Russia’s rotating operational drills along with Vostok (East), Tsentr (Central), and Kavkaz (Caucasus).
- Scale: Zapad-2021 involved ~200,000 personnel from 17 countries, one of the largest recent drills.
Geopolitical Significance:
- Deterrence: Sends a strategic message to NATO about Russian readiness.
- Allied Assurance: Reassures Russia’s partners and allies of its military strength.
| [UPSC 2024] Which of the following statements about ‘Exercise Mitra Shakti-2023’ are correct?
1. This was a joint military exercise between India and Bangladesh.
2. It commenced in Aundh (Pune).
3. Joint response during counter-terrorism operations was a goal of this operation.
4. Indian Air Force was a part of this exercise.
Select the answer using the code given below:
Options: (a) 1, 2 and 3 (b) 1 and 4 (c) 1 and 4 (d) 2, 3 and 4* |
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Why in the News?
The Union Culture Ministry has invited experts to present their research on deciphering the Indus Valley script, also known as the Harappan script.
Recent Efforts and Theories on the Harappan Script:
- Taxation & Commerce Theory: Bahata Ansumali Mukhopadhyay argues the script encodes rules of trade and taxation, not phonetic spellings.
- Religious Hypothesis: Karuna Shankar Shukla claims Indus seals carried Rig Vedic mantras and Puranic references, used mainly for rituals.
- Proto-Dravidian Claims:
- Prakash N. Salame (Nagpur engineer) says 90% of symbols represent Proto-Dravidian Gondi, building on Dr. M. C. Kangali.
- Asko Parpola (Finnish Indologist) supports the Dravidian hypothesis, suggesting a logo-syllabic system of pictograms and rebuses.
- Bryan K. Wells also backs Proto-Dravidian links.
- Santali Link: Prabhunath Hembrom connects the script to the Santali language, citing parallels with Parpola’s work.
- Scholarly Caveats: H. P. Ray stresses need for bilingual objects, contextual clarity, and warns against assuming a single language for the entire civilization.
Back2Basics: Indus Valley Civilization (IVC)
- Timeline: Flourished 2600–1900 BCE, with roots back to Mehrgarh (7000 BCE).
- Extent: Covered 1.5 million sq. km across modern India, Pakistan, Afghanistan.
- Discovery: Excavations at Harappa (1921–22, Daya Ram Sahni) and Mohenjo-daro (1922, R. D. Banerji) confirmed as one civilization by John Marshall.
- Urban Features: Grid-planned cities, fortified towns, granaries, warehouses, dockyards, drainage systems, advanced water management (wells, reservoirs, Great Bath).
- Seals & Script: Steatite seals with animal motifs and undeciphered script point to complex administration.
- Crafts & Finds: Pottery, bead-making, weaving, metallurgy, toys, ornaments, figurines; iconic Dancing Girl, Priest-King, Mother Goddess statues.
|
| [UPSC 2001] Which one of the following animals was NOT represented on the seals and terracotta art of the Harappan culture?
Options: (a) Cow* (b) Elephant (c) Rhinoceros (d) Tiger |
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Why in the News?
Tiwa tribesmen recently celebrated Langkhun festival in Umsowai village in Karbi Anglong district of Assam.
About Langkhon Festival:
- Overview: A pre-harvest thanks-giving festival of the Tiwa tribe of Assam.
- Timing: Celebrated in October–November, just before the Rabi crop season.
- Core Belief: Involves worship of bamboo, seen as a symbol of prosperity and sustenance in Tiwa culture.
- Deities: Special prayers to Ramsa Devota and other local gods for crop protection, family welfare, and village prosperity.
- Ritual Practices: Include offerings, sacrifices, and prayers to drive away pestilence and evil forces and ensure a good paddy harvest.
- Duration: Celebrated for 2–4 days with active community participation.
- Traditional Dances: Langkhon dance, Moinari Khanthi, and Yangli form the cultural highlights.
- Folk Songs: Songs such as Lo Ho La Hai (naming, weddings, harvests) and Lali Hilali Lai (weddings) are integral to the festival.
- Games & Sports: Local games like Plasele and Sam Kava are organised, strengthening community bonds.
| [UPSC 2018] Consider the following pairs: Tradition | State
1. Chapchar Kut festival — Mizoram
2. Khongjom Parba ballad — Manipur
3. Thong-To dance — Sikkim
Which of the pairs given above is/are correct?
Options: (a) 1 only (b) 1 and 2* (c) 3 only (d) 2 and 3 |
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Why in the News?
Thiru CP Radhakrishnan has been elected as Vice President of India.
About Vice-President (VP) of India:
- Position: Second-highest constitutional post; deputy to the President.
- Parliamentary Role: Serves as ex-officio Chairman of the Rajya Sabha.
- Succession: Ranks second in order of precedence and first in line to become President.
- Membership: Is a member of Parliament, not directly elected by the people.
Qualifications:
- Citizenship: Must be a citizen of India.
- Age: Minimum 35 years.
- Office of Profit: Should not hold any.
- Parliamentary Eligibility: Must qualify for election to Rajya Sabha (unlike President, who must qualify for Lok Sabha) due to the VP’s role in the Upper House.
Roles and Responsibilities:
- Rajya Sabha Chairmanship: Presides over sessions and ensures order.
- Bill Classification: Refers money bills to the Lok Sabha Speaker.
- No Independent Powers: Has no executive or legislative powers unless acting as President.
Election Procedure:
- Constitutional Basis: Governed by Article 66.
- Electoral College: Comprises 543 Lok Sabha MPs, 233 elected Rajya Sabha MPs, and 12 nominated Rajya Sabha members.
- Voting Method: Proportional representation by single transferable vote and secret ballot.
- No Whip Allowed: Parties cannot issue voting whips.
- Conduct: Managed by the Election Commission; Returning Officer is the Secretary-General of either House (on rotation).
- Winning Quota: Requires 50% of valid votes + 1; votes are transferred in rounds if no candidate secures majority in the first round.
Resignation and Removal:
Resignation
- Article 67(a): VP submits his/her resignation to the President. Parliamentary approval is NOT needed, and the resignation takes effect immediately upon receipt.
- No Acting VP: Constitution doesn’t provide for an acting Vice-President.
- Presiding in Absence: Deputy Chairman of Rajya Sabha presides in VP’s absence (currently Harivansh Narayan Singh).
- Example: Dhankhar, who took office in 2022, is only the third VP in Indian history to resign before completing his term, after V.V. Giri and R. Venkataraman.
Removal
- Article 67(b): Removal process begins in Rajya Sabha with 14 days’ notice.
- Voting Requirement: Needs effective majority in Rajya Sabha and simple majority in Lok Sabha.
- No Grounds Specified: Constitution doesn’t list specific removal grounds.
- Judicial Immunity: Article 122 bars courts from questioning parliamentary proceedings related to removal.
- No Precedent: No VP has been removed so far.
| [UPSC 2013] With reference to Parliament, consider the following statements:
1.The Chairman and the Deputy Chairman of the Rajya Sabha are not the members of that House.
2.While the nominated members of the two Houses of the Parliament have no voting right in the presidential election, they have the right to vote in the election of the Vice President.
Which of the statements given above is/are correct?
Options: (a) 1 only (b) 2 only (c) Both 1 and 2* (d) Neither 1 nor 2 |
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Why in the News?
A recent study (2025, Science) found young neurons in the adult brain, challenging the old belief that Neurogenesis (neurons formation) occur only in childhood.
What is Neurogenesis?
- Overview: Formation of new neurons from stem or progenitor cells.
- Established in Animals: Well-known in mice, rats, and monkeys; also active during human childhood development.
- Debate in Humans: Longstanding question if it continues in adulthood, especially in the hippocampus (brain’s memory and learning hub).
- Hippocampal Role: The dentate gyrus is believed to sustain lifelong neurogenesis, helping in memory formation, flexibility, and stress control.
Key findings of the Study:
- Conducted by: Karolinska Institutet, Stockholm, published in Science (2025).
- Study: Analysed 400,000 neurons from post-mortem hippocampus samples of people aged from infants (<1 year) to 78 years.
- Methodology: Used single nuclei RNA sequencing with machine learning to detect signs of new cells.
- Outcome: Validated with RNAscope and Xenium imaging, which confirmed the presence of neural stem cells, progenitors, and young neurons (neuroblasts) even in adolescent and adult brains.
Why are the findings important?
- Evidence in Adults: Strong proof that new neurons form in adult brains, not just in early years.
- Evolutionary Insight: Suggests neurogenesis is a conserved feature across mammals, not unique to certain species.
- Brain Functions: Explains memory flexibility, ability to overwrite memories, and resilience to stress.
- Therapeutic Potential: Opens up scope for regenerative treatments in brain disorders like Alzheimer’s, Parkinson’s, and dementia by stimulating local progenitor cells.
- Lifestyle Link: Implies that exercise, social connections, and stress levels could influence how much neurogenesis happens in individuals.
| [UPSC 2024] Which one of the following is synthesised in human body that dilates blood vessels and increases blood flow?
Options: (a) Nitric oxide* (b) Nitrous oxide (c) Nitrogen dioxide (d) Nitrogen pentoxide |
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Why in the News?
The United States is preparing to reinterpret the 1987 Missile Technology Control Regime (MTCR) to expand exports of heavy attack drones, like the MQ-9 Reaper, to partner countries.
About Missile Technology Control Regime (MTCR):
- Formation: Established in 1987 by the G-7 countries (Canada, France, Germany, Italy, Japan, UK, USA) to prevent the spread of missiles and UAVs capable of delivering nuclear, chemical, or biological weapons.
- Membership: Today, 35 countries are members; India joined in 2016.
- Nature: Not a treaty but a voluntary political understanding where members implement export control guidelines.
-
Coverage:
- Category I items: Complete missile/UAV systems with ≥500 kg payload and ≥300 km range, major subsystems, and production facilities (exports presumed denied).
- Category II items: Less sensitive or dual-use components/technologies; exports subject to national discretion under strict licensing.
- Purpose: To limit missile proliferation while allowing peaceful space and aviation cooperation.
About the Recent Policy Change on MTCR:
-
US Reinterpretation (2025):
- Large unmanned aerial vehicles (UAVs) like the MQ-9 Reaper will be treated as “aircraft” instead of missile systems.
- This removes the “strong presumption of denial” that earlier restricted their export under MTCR.
- Objective: To make the US the leading drone supplier, countering competition from China, Israel, and Turkiye.
-
Implications:
- Opens the door for Foreign Military Sales (FMS) of heavy attack drones to partners like Saudi Arabia, India, and Indo-Pacific allies.
- Still subject to US reviews for regional stability, end-use monitoring, tech security, and human rights compliance.
- Facilitates India–US space and defence cooperation, lowering barriers for joint ventures and technology partnerships.
| [UPSC 2022] Consider the following:
1. Asian Infrastructure Investment Bank 2. Missile Technology Control Regime 3. Shanghai Cooperation Organisation
India is a member of which of the above?
Options: (a) 1 and 2 only (b) 3 only (c) 2 and 3 only (d) 1, 2 and 3 |
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Why in the News?
The recent discovery of a massive freshwater aquifer beneath the Atlantic shelf opens new possibilities for addressing future global water shortages.
About the Aquifer:
- Location: Offshore northeastern U.S., stretching possibly from New Jersey to Maine.
- Expedition 501: Drilled up to 400 m beneath the seabed, retrieving nearly 50,000 liters of water and thousands of sediment cores.
- Findings: Fresh and nearly fresh water discovered at both shallower and deeper depths than expected, confirming a vast, pressurized aquifer.
- Global Context: Similar offshore aquifers are suspected or identified near South Africa, Hawai‘i, Jakarta, and Canada’s Prince Edward Island.
Possible Origins of the Freshwater:
- Glacial Meltwater Hypothesis: Ancient ice sheets during lower sea levels allowed meltwater to seep into porous sediments.
- Connected Aquifer Hypothesis: Modern terrestrial groundwater may still slowly flow offshore through geologic formations.
- Significance: Determining whether the aquifer is finite fossil water or a renewable source is critical for deciding its usability.
Significance of the Discovery:
- Water Security: Could supply a metropolis the size of New York City for centuries, if managed sustainably.
- Climate Change Resilience: Offers backup options as coastal aquifers face saltwater intrusion and urban demand rises (e.g., Cape Town’s “Day Zero” crisis in 2018).
- Scientific Impact: First direct, systematic drilling of offshore freshwater for mapping and salinity profiling.
| [UPSC 2021] With reference to the water on the planet Earth, consider the following statements:
1.The amount of water in the rivers and lakes is more than the amount of groundwater.
2.The amount of water in polar ice caps and glaciers is more than the amount of groundwater.
Which of the statements given above is/are correct?
Options: (a) 1 only (b) 2 only* (c) Both 1 and 2 (d) Neither 1 nor 2 |
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Why in the News?
Sri Lankan President Dissanayake’s visit to Katchatheevu Island, the first ever visit by a head of state, revived debates on the island’s history and ownership.
About Katchatheevu Island:
- Overview: Small uninhabited island of about 285 acres in the Palk Strait, ~33 nautical miles from Jaffna (Sri Lanka) and close to Ramanathapuram (Tamil Nadu).
- History: Once under the Raja of Ramnad (TN), later became disputed during British rule.
- Agreements: Under 1974 and 1976 pacts, India (under Indira Gandhi govt.) recognised Sri Lanka’s sovereignty and gave up traditional fishing rights.
- Religious Site: Home to St. Anthony’s Catholic Shrine, visited annually by Indian and Sri Lankan fishermen during a joint festival with visa waiver.
- Ecology: Though barren and unsettled, serves as a resting point for fishermen and supports marine biodiversity.
Disputes around Katchatheevu:
- Fishing Conflicts: Tamil Nadu fishermen often cross into Sri Lankan waters due to declining catch in Indian waters, leading to frequent arrests by the Sri Lankan Navy.
- Bottom-Trawling Issue: Indian trawlers use bottom-trawling, banned in Sri Lanka, which damages marine ecosystems and escalates tensions.
- Political Demands: All TN political parties have demanded retrieval of the island.
- National Politics: Issue often resurfaces during elections, with claims that earlier governments “easily gave away” Katchatheevu.
- Official Position: India clarified in 2013–14 that no sovereign territory was ceded since the island was disputed, not fully under India’s control.
- Core Problem: Lies not in sovereignty but in unsustainable bottom-trawling practices and the livelihood crisis faced by Tamil Nadu fishermen.
| [UPSC 2020] Consider the following statements:
1. The value of Indo-Sri Lanka trade has consistently increased in the last decade.
2. “Textile and textile articles” constitute an important item of trade between India and Bangladesh.
3. In the last five years, Nepal has been the largest trading partner of India in South Asia.
Which of the statements given above is/are correct? (2020)
Options: (a) 1 and 2 only (b) 2 only* (c) 2 only (d) 3 only |
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Why in the News?
Viewers across Asia, Australia, and parts of Africa witnessed a Blood Moon on 8th September, a spectacular form of total lunar eclipse visible.
About Lunar Eclipse:
- Overview: Happens when Earth comes between Sun and Moon, blocking sunlight from reaching the Moon.
- Earth’s Shadow:
- Umbra: Dark central shadow, causes total or partial eclipses.
- Penumbra: Outer shadow, causes faint dimming.
- Types:
- Total Eclipse: Moon passes fully through umbra.
- Partial Eclipse: Only part of Moon enters umbra.
- Penumbral Eclipse: Moon passes through penumbra with subtle darkening.
- Frequency: Occurs 2–4 times per year, visible from different regions.
Why lunar eclipse don’t occur every month?
: Lunar eclipses don’t happen every month because the Moon’s orbit around the Earth is tilted by about 5 degrees relative to the Earth’s orbit around the Sun. This tilt, known as orbital inclination, means that during a full Moon, the Moon often passes above or below Earth’s shadow, preventing a perfect alignment required for an eclipse. Eclipses only occur when the alignment is precise, allowing the Sun, Earth, and Moon to line up in a straight line. |
What is Blood Moon?
- Meaning: Refers to the reddish glow of the Moon during a total lunar eclipse.
- Cause: Rayleigh scattering in Earth’s atmosphere.
- Short wavelengths (blue, violet) scatter away.
- Longer wavelengths (red, orange) bend around Earth and light the Moon.
- Colour Intensity:
- Presence of dust, aerosols, volcanic ash deepens the red shade.
- Cleaner atmosphere produces a lighter red or orange.
- Historical Insight: Medieval records of Blood Moons helped identify volcanic eruptions between 1100–1300 CE, confirmed by a 2023 University of Geneva study.
Significance:
- Scientific: Acts as a natural indicator of atmospheric composition, dust, and pollution; helps model planetary atmospheres.
- Historical/Environmental: Provides evidence of past volcanic events and climate conditions.
- Cultural: Linked to myths and superstitions, though harmless scientifically.
- Public Engagement: Widely followed celestial event that aids astronomy outreach and awareness.
| [UPSC 2019] On 21st June, the Sun
Options: (a) does not set below the horizon at the Arctic Circle*
(b) does not set below the horizon at Antarctic Circle
(c) shines vertically overhead at noon on the Equator
(d) shines vertically overhead at the Tropic of Capricorn |
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Why in the News?
This year marks the centenary of the Self-Respect Movement in Tamil Nadu, a transformative socio-political reform movement.
About Self-Respect Movement:
- Overview: Started in 1925 by E.V. Ramasamy Periyar in Tamil Nadu after his exit from the Indian National Congress.
- Aim: To challenge Brahminical dominance, caste hierarchy, patriarchy, and blind religious practices; to create a rational, egalitarian society.
- Methods:
- Promotion of Self-Respect Marriages (without priests or caste rituals).
- Advocacy of women’s rights – widow remarriage, divorce, property rights, inter-caste marriage.
- Use of Kudi Arasu journal for spreading radical ideas and reform propaganda.
- Significance:
- Laid the foundation of the Dravidian movement in Tamil Nadu.
- Prioritized social reform over political independence.
- Gave marginalized communities and women a platform for dignity and equality.
Who was E.V. Ramasamy Periyar?
- Overview: Erode Venkatappa Ramasamy (1879–1973), popularly known as Periyar or Thanthai Periyar (“Father Periyar”).
- Identity: Social reformer, rationalist, and political thinker; called the “Father of the Dravidian Movement.”
- Key Roles:
- Led the Vaikom Satyagraha (1924-25) in Kerala against caste restrictions in temples, earning the title “Vaikom Hero.”
- Founded the Self-Respect Movement (1925) and later Dravidar Kazhagam.
- Ideology:
- Advocated rationalism, atheism, equality, and eradication of caste.
- Strongly opposed gender inequality and social exploitation.
- Legacy: Inspired later Dravidian parties (DMK, AIADMK) and influenced Tamil Nadu’s policies on social justice, women’s rights, and education.
| [UPSC 2025] Who among the following was the founder of the ‘Self-Respect Movement’?
Options:
(a) ‘Periyar’ E. V. Ramaswamy Naicker* (b) Dr. B. R. Ambedkar (c) Bhaskarrao Jadhav (d) Dinkarrao Javalkar |
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Why in the News?
A recent study has showcased that spacecrafts can locate themselves using a simple stellar parallax method with just two nearby stars, without relying on Earth.
What is Stellar Parallax?
- Overview: Stellar parallax is the apparent shift in a star’s position against background stars when observed from two different vantage points.
- Example: On Earth, this is measured every 6 months as the planet moves to opposite sides of its orbit.
- Parallax Angle: The degree of this shift gives the star’s distance. Larger parallax means the star is closer.
- Application in Space: By observing stars from both Earth and a spacecraft (billions of km apart), the relative positions can be compared to calculate the spacecraft’s distance.
About the New Horizons Demonstration:
- Spacecraft: Launched in 2006, New Horizons explored Pluto (2015) and is now beyond 60 AU (astronomical units).
- Observation: On April 23, 2020, astronomers measured parallaxes of Proxima Centauri (4.2 light years) and Wolf 359 (7.9 light years) using Earth-based telescopes and New Horizons’ onboard instruments.
- Results:
- Proxima’s parallax: 32.4 arcseconds
- Wolf 359’s parallax: 15.7 arcseconds
- Derived spacecraft position: 46.89 AU, matching DSN’s 47.11 AU reading.
- Requirements: Only a camera, onboard computer, and stellar catalogue — no special equipment needed.
Significance:
- Self-sufficient Navigation: Enables spacecraft to calculate their position without depending solely on Earth-based radio signals.
- For Future Missions: Particularly useful for interstellar missions, where Earth’s beacons won’t be practical.
- Simplicity: Unlike more complex astrometric navigation or pulsar navigation, this method is accessible with minimal hardware.
- Educational Value: Though not precise enough yet for real-time navigation, it is a proof of concept for deep-space autonomy.
| [UPSC 2012] A person stood alone in a desert on a dark night and wanted to reach his village which was situated 5 km east of the point where he was standing. He had no instruments to find the direction, but he located the polestar. The most convenient way now to reach his village is to walk in the:
Options: (a) direction facing the polestar
(b) direction opposite to the polestar
(c) direction keeping the polestar to his left *
(d) direction keeping the polestar to his right |
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Why in the News?
The facial tattoos and wooden nose plugs of Apatani women in Arunachal Pradesh, banned in the 1970s, now survive only among older generations, giving them anthropological importance.
About Apatani Tribe:
- Overview: A Scheduled Tribe (ST) concentrated in Ziro Valley, Lower Subansiri district, Arunachal Pradesh.
- Language: Part of the Tani linguistic group, speaking a dialect of the Tibeto-Burman family.
- Belief System: Paganistic faith worshipping the Sun (Ayo Danyii) and Moon (Atoh Piilo).
- Festivals: Dree (prayers for harvest and prosperity), Myoko (friendship bonds), along with Yapung and Murung.
- Global Recognition: Ziro Valley noted for traditional ecological knowledge, proposed as a UNESCO World Heritage Site.
Unique Features:
- Distinct Identity: Women traditionally had facial tattoos and wooden nose plugs; banned since the 1970s, seen only among older women today.
- Sustainable Farming: Practise integrated rice-fish farming on terraced fields, growing rice varieties like Mipya, Emoh, Emeo along with fish (Ngihi).
- Weaving Tradition: Women weave on a loin loom (Chichin), producing fabrics with geometric and zig-zag designs, dyed with natural extracts.
- Bamboo Culture: Bamboo central to daily life, crafts, and rituals, symbolising ecological harmony.
- Community Systems: Maintain sustainable social forestry and village institutions for conservation and cultural continuity.
| [UPSC 2014] Consider the following pairs:
Tribe : State
1. Limboo (Limbu) : Sikkim
2. Karbi : Himachal Pradesh
3. Dongaria Kondh : Odisha
4. Bonda : Tamil Nadu
Which of the above pairs are correctly matched?
Options: (a) 1 and 3 only* (b) 2 and 4 only (c) 1, 3 and 4 only (d) 1, 2, 3 and 4 |
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Why in the News?
A recent study published in the Nature suggests that simple molecules called aminoacyl-thiols may have helped amino acids stick to RNA (ribonucleic acid) without enzymes, giving clues to how protein-making began on early Earth.
About the RNA–Amino Acid Link:
- Discovery: Study showed that aminoacyl-thiols (simple prebiotic molecules) can attach amino acids to RNA directly (aminoacylation) without enzymes.
- Modern Parallel: In cells today, this is done by aminoacyl-tRNA synthetases before ribosomes build proteins. This created the “chicken-and-egg problem”: proteins are needed to make proteins.
- Chemical Mechanism:
- Thioesters: Enable amino acids to attach to RNA (“charging RNA”).
- Thioacids: Enable amino acids to link into peptides.
- Robustness: Works at neutral pH, across many amino acids, with unexpected selectivity for RNA despite other molecules being more reactive.
Significance for Origin of Life:
- RNA World Hypothesis: Supports the idea that RNA and amino acids interacted directly before enzymes evolved.
- Chemical Advantage: Shows RNA had a natural edge in early Earth conditions, explaining its central role in life’s origin.
- Prebiotic Plausibility: Aminoacyl-thiols could form from simple nitriles and thiols, and reactions occurred even in cold/frozen pools resembling early Earth.
- Evolutionary Pathway: Suggests life began with short peptides, with RNA later evolving control, leading to coded protein synthesis and ribosomes.
| [UPSC 2022] Consider the following statements : DNA Barcoding can be a tool to:
1. assess the age of a plant or animal.
2. distinguish among species that look alike.
3. identify undesirable animal or plant materials in processed foods.
Which of the statements given above is/are correct ?
Options: (a) 1 only (b) 3 only (c) 1 and 2 (d) 2 and 3* |
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Why in the News?
The Ministry of Defence has released the Technology Perspective and Capability Roadmap 2025 (TPCR-2025), a 15-year blueprint for military preparedness and modernization.
About Technology Perspective and Capability Roadmap (TPCR-2025):
- Overview: A strategic modernization blueprint released by the Ministry of Defence to guide India’s Armed Forces for the next 10–15 years.
- Scope: Covers tri-services for multi-domain operations across land, sea, air, cyber, and space.
- Industry Role: Provides clear requirements to defence industry, MSMEs, and start-ups to focus R&D, manufacturing, and innovation.
- Policy Alignment: Linked to Atmanirbhar Bharat, reducing import dependence and strengthening indigenous production.
- Objective: Ensure forces remain technologically competitive, prepared for emerging threats, and resilient in a dynamic security environment.
Key Features of TPCR-2025:
- Nuclear & CBRN Preparedness: Strengthening nuclear command systems, survivability infrastructure, radiation detection, decontamination units, unmanned CBRN (Chemical, Biological, Radiological, and Nuclear) vehicles.
- Drones & Unmanned Systems: Development of stealth drones (range 1,500 km, altitude 60,000 ft), AI-enabled loitering munitions, anti-drone EW bubbles.
- Electronic & Cyber Warfare: Deployment of advanced jammers, EW payloads, info-dominance systems, and readiness for cyber and space warfare.
- Service Modernization:
- Army: New tanks, light tanks, UAV-launched PGMs, electromagnetic weapons.
- Navy: New destroyers, corvettes, mine vessels, nuclear-powered warships, third aircraft carrier.
- Air Force: Stratospheric airships, long-range cruise missiles, hardened PGMs.
- Implementation: Regular industry–services consultations, engagement with MSMEs and start-ups, periodic updates.
Significance:
- Serves as a capability roadmap for long-term defence planning.
- Strengthens domestic defence ecosystem.
- Ensures future combat readiness in multi-domain operations.
| [UPSC 2020] In India, why are some nuclear reactors kept under “IAEA safeguards” while others are not?
Options: (a) Some use uranium and others use thorium
(b) Some use imported uranium and others use domestic supplies
(c) Some are operated by foreign enterprises and others are operated by domestic enterprises
(d) Some are State-owned and others are privately owned * |
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Why in the News?
Cold fusion reaction, once dismissed after failed 1989 claims, is back in discussion as US-based researchers report neutron production from their small “Thunderbird Reactor.”
What is Cold Fusion Reaction?
- Overview: A proposed way to achieve nuclear fusion at room temperature, unlike conventional fusion which needs extremely high heat (100 million °C or more).
- How it started: In 1989, two chemists, Martin Fleischmann and Stanley Pons, said their palladium-heavy water experiment created more heat than normal chemistry allows.
- Problem: Other scientists could not reproduce the result. No clear evidence of fusion products (like neutrons or helium) was found. The claim was dismissed, but the idea stayed alive.
- Why interest remains: If proven, cold fusion could provide limitless, clean, and cheap energy. Research in this area is now called Low-Energy Nuclear Reactions (LENR).
About the Thunderbird Reactor (2025)
- Inception: Scientists led by Curtis Berlinguette, University of British Columbia, published in Nature (Aug 2025).
- Why built: Not to make electricity, but to test if chemistry can affect nuclear reactions.
- How it works:
- A plasma thruster shoots deuterium ions (a form of hydrogen) at a palladium metal target.
- At the same time, an electrochemical cell pushes more deuterium into the palladium.
- This builds up a very high density of deuterium inside the metal, making fusion more likely.
- A neutron detector checks if fusion really happens.
Key Findings:
- Neutrons detected: When deuterium ions hit palladium, about 130–140 neutrons per second were observed (much higher than background levels).
- Electrolysis boost: Adding extra deuterium through electrolysis increased the neutron count further.
- Energy output: The reaction only produced a tiny amount of power (one-billionth of a watt) while consuming 15 watts of electricity. No net energy gain yet.
| [UPSC 2016] India is an important member of the ‘International Thermonuclear Experimental Reactor’. If this experiment succeeds, what is the immediate advantage for India?
Options: (a) It can use thorium in place of uranium for power generation
(b) It attain a global role in satellite-navigation
(c) It can drastically improve the efficiency of its fission reactors in power generation
(d) It can build fusion reactors for power generation* |
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Why in the News?
The Agricultural and Processed Food Products Export Development Authority (APEDA) has launched the BHARATI initiative — Bharat’s Hub for Agritech, Resilience, Advancement and Incubation for Export Enablement.
About BHARATI Initiative:
- Launched by: APEDA (Agricultural and Processed Food Products Export Development Authority) in September 2025.
- Purpose: To incubate and empower 100 agri-food and agri-tech startups, making them export-ready.
- Target: Support APEDA’s vision of reaching US$ 50 billion (₹4.4 lakh crore) in agri-food exports by 2030.
- Focus Areas: Export enablement, innovation, incubation, and addressing challenges like perishability, logistics, quality compliance, and sustainability.
- Policy Alignment: Linked to Atmanirbhar Bharat, Start-Up India, Vocal for Local, and Digital India.
Key Features:
- Targeted Products: GI-tagged items, organic foods, superfoods, AYUSH products, processed foods, livestock-based products.
- Technology Integration: AI-based quality control, blockchain-enabled traceability, IoT-based cold chains, and agri-fintech solutions.
- Acceleration Model: 3-month programme to build export readiness, ensuring compliance with international food safety and quality standards.
- Partnership Ecosystem: Collaboration with state boards, IITs/NITs, universities, industry bodies, and accelerators.
- Scalability: Designed for annual expansion, gradually increasing the number of supported startups.
| [UPSC 2011] With what purpose is the Government of India promoting the concept of “Mega Food Parks”?
1. To provide good infrastructure facilities for the food processing industry.
2. To increase the processing of perishable items and reduce wastage.
3. To provide emerging and
eco-friendly food processing technologies to entrepreneurs.
Select the correct answer using the code given below:
Options: (a) 1 only (b) 1 and 2 only* (c) 2 and 3 only (d) 1, 2 and 3 |
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Why in the News?
The Ministry of Tribal Affairs (MoTA) has written to the Registrar General and Census Commissioner of India (RGI) to enumerate PVTGs separately in Census 2027.
Who are the PVTGs?
- Overview: Sub-category of Scheduled Tribes (STs) marked by stagnant or declining population, geographical isolation, pre-agrarian subsistence, economic backwardness, and very low literacy.
- Origin: Concept recommended by the Dhebar Commission (1960–61) noting inequalities among STs.
- Historical Evolution:
- Fourth Five-Year Plan (1969–74): creation of Primitive Tribal Groups (PTGs).
- Fifth Five-Year Plan (1974–79): 52 groups identified.
- 2006: PTGs renamed as PVTGs.
- Present Status: 75 PVTGs recognized across 18 states and 1 UT (Andaman & Nicobar Islands).
- Characteristics: Small numbers, remote habitation, pre-agricultural practices, hunting and gathering reliance, and in some cases zero or negative population growth.
Enumeration and Population Estimates:
- 2011 Census Status: PVTGs were NOT separately enumerated, counted under the broader ST category.
- Special Cases:
- 2011 Census: Baigas counted separately, while Abujh Marias, Bharias, Hill Korbas, Kamars subsumed under STs.
- 2013: Abujh Maria and Hill Korba explicitly added to Chhattisgarh’s ST list via legislation.
- Recent Estimates: 2023 PM JANMAN survey estimated the population at 47.5 lakh.
- Madhya Pradesh: 13.22 lakh (highest).
- Maharashtra: about 6.7 lakh.
- Andhra Pradesh: about 5.18 lakh.
- Largest and Smallest:
- Largest: Baiga of Madhya Pradesh with about 4.14 lakh.
- Smallest: Sentinelese of Andaman & Nicobar Islands with just 15 individuals.
- Micro Groups: In 2011, 13 PVTGs had populations below 1,000 including Jarawa, Onge, Sentinelese, Shompen (A&N Islands), Raji (Uttarakhand), Kota (Tamil Nadu), Birhor (Odisha/Bihar), Kamar (Madhya Pradesh), and others.
| [UPSC 2019] Consider the following statements about Particularly Vulnerable Tribal Groups (PVTGs) in India:
1. PVTGs reside in 18 States and one Union Territory.
2. A stagnant or declining population is one of the criteria for determining PVTG status.
3. There are 95 PVTGs officially notified in the country so far.
4. Irular and Konda Reddi tribes are included in the list of PVTGs.
Which of the statements given above are correct?
Options: (a) 1, 2 and 3 (b) 2, 3 and 4 (c) 1, 2 and 4* (d) 1, 3 and 4 |
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Why in the News?
Singapore’s PM has acknowledged India’s intent to join the Malacca Straits Patrol (currently undertaken by Malaysia, Indonesia, Thailand, and Singapore).
About Strait of Malacca:
- Location: Narrow waterway in Southeast Asia, between the Malay Peninsula (northeast) and Sumatra, Indonesia (southwest).
- Length & Width: Extends about 800–900 km; width varies from 65 km in the south to 250 km in the north.
- Depth: The southern end is narrow and shallow, usually less than 37 m deep, posing navigational challenges.
- Geological Setting: Part of the Sunda Shelf formation, created after post-glacial sea level rise around 2.6 million years ago.
- Key Ports: Hosts major hubs like Singapore, Port Klang, Penang, and Melaka, making it one of the busiest shipping lanes globally.
Strategic and Economic Importance:
- Global Chokepoint: Links the Indian Ocean (Andaman Sea) with the Pacific Ocean (South China Sea), forming a vital maritime chokepoint.
- Trade Corridor: The shortest sea route between the Middle East/Africa and East Asia, critical for global commerce.
- Volume of Trade: Handles about 60% of world maritime trade, including large-scale oil shipments from the Middle East to China, Japan, and Southeast Asia.
- Economic Impact: Any disruption could severely affect supply chains and energy security worldwide.
- Geopolitical Significance: Attracts competing interests of India, China, the US, and ASEAN states, making it a hotspot for regional and global strategic rivalry.
| [UPSC 2010] Which one of the following can one come across if one travels through the Strait of Malacca ?
Options: (a) Bali (b) Brunei (c) Java (d) Singapore* |
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