UPSC Weekly Concepts Snapshot: A Moon, the New IIP Series and a Storm

The Union Public Service Commission (UPSC) Civil Services Examination, whether at the Prelims or Mains stage, is no longer just about what you know, but how clearly you understand it. The exam increasingly tests your conceptual clarity and ability to apply core ideas, especially in the most dynamic subjects — Science, Economy, and Environment. 

If you missed the previous UPSC Weekly Concepts Snapshot: Energy storage technologies, Bond Yield and ENSO from the Indian Express, read it here.

Read the article. Then crack the quiz.

SCIENCE

Blue micromoon

Core Concept: 

— Though the expression “once in a blue moon” implies a rare or unusual occurrence, a blue moon is not that rare an astronomical event.

— There are a few definitions of a blue moon. One that is most commonly understood — and endorsed by NASA — describes a situation when a full moon is seen twice in a single month. Because the new moon to new moon cycle lasts 29.5 days, a time comes when the full moon occurs at the beginning of a month, and there are days left still for another full cycle to be completed.

— Such a month, in which the full moon is seen on the 1st or 2nd, will have a second full moon on the 30th or 31st. According to NASA, this happens every two or three years.

— Sometimes, smoke or dust in the air can scatter red wavelengths of light, as a result of which the moon may, in certain places, appear more blue than usual. But this has nothing to do with the name “blue” moon, and the association of the colour with the term is unclear.

Micro moon

— The size of the moon, as perceived from earth, is dependent on its location within its orbit around the earth. The moon’s orbit is an elongated or stretched-out circle and it takes 27.3 days to orbit the earth. 

— According to NASA, the moon is about 363,711 km away at its closest to earth, known as perigee. At apogee, or the furthest point, the moon is about 403,945 km away.

(Infographic: AI-generated)

— A smaller-than-usual moon is observable when the Moon’s fully illuminated phase occurs within a short time of apogee. On the other hand, a supermoon occurs when the moon is passing through or is close to its perigee. 

— Notably, when seen in terms of both (Blue and micomoon) phenomena happening simultaneously, then it is a rare event. “Although the next micromoon occurs next month, and the next blue moon at the end of 2028, the next blue micromoon will not occur until 2053,” NASA stated. 

📍UPSC Twist Points: Lunar eclipse 

— There are two types of eclipses: lunar and solar. During a lunar eclipse, Earth’s shadow obscures the Moon. During a solar eclipse, the Moon blocks the Sun from view. 

— Lunar eclipses occur at the full moon phase. When Earth is positioned precisely between the Moon and the Sun. Solar eclipses occur only at the new moon phase, when the Moon is positioned between Earth and the Sun. 

— Types of Lunar Eclipses

1. Total lunar eclipses: The Moon moves into the inner part of Earth’s shadow, or the umbra. Some of the sunlight passing through Earth’s atmosphere reaches the Moon’s surface, lighting it dimly. Colors with shorter wavelengths ― the blues and violets ― scatter more easily than colors with longer wavelengths, like red and orange.

2. Partial lunar eclipse: An imperfect alignment of Sun, Earth and Moon results in the Moon passing through only part of Earth’s umbra. The shadow grows and then recedes without ever entirely covering the Moon.

3. Penumbral eclipse: The Moon travels through Earth’s penumbra, or the faint outer part of its shadow. The Moon dims so slightly that it can be difficult to notice.

ECONOMY

New Index of Industrial Production (IIP)  

Core Concept:

— As the name suggests, the Index of Industrial Production maps the change in the volume of production in Indian industries. More formally, it chooses a basket of industrial products — ranging from the manufacturing sector to mining to energy, creates an index by giving different weights to each sector and then tracks the production every month. Finally, the index value is compared to the value it had in the same month last year to figure out the economy’s industrial health. 

— Major Changes in New Series of All India IIP

1. Revised Base Year: The MoSPI has revised the base year of the IIP from 2011–12 to 2022–23 to make the index more representative of the current structure and dynamics of the industrial sector. 

2. Expanded scope and coverage: In the new IIP series, the coverage has been broadened by incorporating an entire new sector- Gas Supply and Water Supply, Sewerage & Waste Management activities, while retaining the existing three core sectors—Mining, Manufacturing, and Electricity. 

3. Revamped Item Basket: The item basket and weights have been revised to add relevant commodities and remove outdated ones. The revised basket consists of 1,042 products mapped to 463 item groups as compared to 839 items mapped to 407 item groups in 2011-12 series. Examples of  included and deleted items are: 

— Additions: Cards with a magnetic stripe, CCTV camera, Articles of non-woven textiles, Parts of aircraft and spacecraft, Stents, Vaccine (other than veterinary).

— Deletions: Kerosene, Fluorescent tubes and CFLs, Tubes for bicycle/ tricycle/ rickshaw tyres. Tubes for LMV tyres, Printing machinery, Sewing machines.

4. Updated Weights: The weights are updated in the new IIP based on the latest data on Gross Value Added from the National Accounts Statistics (base 2022-23) at the sectoral level and the Annual Survey of Industries at NIC-2/3/4-digit for the financial year 2022-23. 

📍UPSC Twist Points: Index of Eight Core Sector Industries

— The Office of Economic Adviser within the Department for Promotion of Industry and Internal Trade releases the Index of Eight Core Industries (ICI). 

– The base year of ICI is 2011-12. It measures the combined and individual performance of production of eight core industries viz. Coal, Crude Oil, Natural Gas, Refinery Products, Fertilizers, Steel, Cement and Electricity.

— According to the Ministry of Commerce and Industries, the Eight Core Industries comprise 40.27 percent of the weight of items included in the Index of Industrial Production. The Petroleum Refinery Products has maximum weightage with 28.04 per cent.

ENVIRONMENT

Dust Storm

Core Concept: 

— Dust storms primarily originating from the Thar Desert are not unusual over northern India in the pre-monsoon months of April to June. These storms are fuelled by intense heat and dry conditions, while south-westerly and westerly winds move the dust across the region. 

— The India Meteorological Department’s (IMD) Climate Hazards and Vulnerability Atlas of India, based on 1981-2010 climatological normals, shows that parts of northwest India fall in the highest dust-storm frequency class, averaging 0.89 to 1.55 dust-storm days. 

— According to IMD, dust storms are common meteorological hazards in arid and semiarid regions. It is usually caused by thunderstorms or strong pressure gradients associated with cyclones which increase wind speed over a wide area. 

— These strong winds lift large amounts of sand and dust from bare, dry soils into the atmosphere, transporting them hundreds to thousands of kilometers away. 

(Infographic: AI-generated)

— According to National Disaster Management Authority’s Guidelines for Preparation of Action plan – Prevention and Management of Thunderstorm & Lightning/ Squall/Dust/Hailstorm and Strong Winds, dust storm  is of three types:

(1) Slight dust storm: If the wind speed is up to 41 kmph and visibility is less than 1,000 metres but more than 500 meters.

(2) Moderate dust storm: If the wind speed is between 42-74 kmph and visibility is between 200 and 500 metres.

(3) Severe dust storm: If the surface wind speed (in gusts) exceeds 74 kmph and visibility is less than 200 metres.

📍UPSC Twist Points: Squall

— A squall is defined as a sudden increase of wind speed of at least 29 kmph (16 knots) with the speed rising to 40 kmph (22 knots) or more and lasting for at least one minute. It is of two types:

(1) Moderate squall: If the surface wind speed (in gusts) is up to 74 kmph.

(2) Severe squall: If the surface wind speed (in gusts) is greater than 74 kmph.

— The frequency and intensity of squall are maximum over eastern and northeastern States. Also, its frequency is maximum during the pre-monsoon season with an increasing trend from March to May in different parts of the country. However, there is a secondary maximum in the winter season over northwest India.

Prelims Practice MCQ

Let’s see how much can you recall

Consider the following statements:

1. A Blue Moon refers to the second full moon occurring in a calendar month, while a Micromoon occurs when the full moon appears near the Moon’s farthest point from Earth.

2. The revised Index of Industrial Production (IIP) series has 2023–24 as its base year.

3. According to the classification used in India, a severe dust storm is characterised by wind speeds exceeding 74 kmph and visibility less than 200 metres.

Which of the statements given above are correct?

(a) 1 and 2 only

(b) 2 and 3 only

(c) 1 and 3 only

(d) 1, 2 and 3

ALSO CHECK

UPSC Prelims S.E.E. Snapshot: GPS interference, RBI’s Monetary Policy, Heatwaves

UPSC Prelims S.E.E. Snapshot: Dimethyl Ether, CPI overhaul, Tar Balls 

UPSC Prelims ‘SEE’ Snapshot : Induction cooktop, Forex reserve, and Earth’s energy imbalance 

UPSC Prelims ‘SEE’ Snapshot: Talking cars, GDP rebasing and Nor’westers — quick look 

🚨 Click Here to read the UPSC Essentials magazine for May 2026. Share your views and suggestions in the comment box or at manas.srivastava@indianexpress.com🚨 

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