Everyday Science — Chapter 1
The Universe & the Solar System — Big Bang, Stars, the Sun, the Planets, the Moon and the Eclipses
Why this chapter matters: this is the first Everyday Science chapter, and it is one of the highest-yield chapters in the whole notes set. Our verified banks hold 81 questions matching this topic by question text, spread across every section of the chapter — and the same facts return in General Knowledge and Geography papers too. The weight sits exactly where this chapter puts it: the Sun and the solar system (24 questions) — light year, astronomical unit, Sun-spots, the Sun’s centre temperature — followed by the planets (16), the universe, stars and black holes (15), the Moon and the sky (14) and the eclipses and the Earth’s motions (12). The lecture (EDS Lecture 1) teaches the whole topic at full depth, and the IBES Everyday Science capsule bank sits behind it. Learn the planet table in Section 4 and the eclipse/motion pairs in Section 6 and the chapter answers itself.
Exam Trend box: 🔁 most repeated in this chapter — the Sun & solar system facts, the planet table and the Milky Way’s spiral shape (see Section 8 for the counts). ⭐ must-know — the same families, still the core of every paper’s astronomy block. 🆕 newly appeared — the 2025 space year, Section 6A (12 dated rows, origin year 2025, from the gk360 monthly CA bank): NISAR, the Pakistan EO-1 / KS-1 / HS-1 trio, 3I/ATLAS, the Uranus 29th moon and the Shenzhou-20 debris return. No 🔁/⭐ mark is claimed for the Section 6A table itself — one year only — and its bank rows are corrected where the bank is wrong (see Section 9).
1. The universe — the big definitions and the big theories
- Universe = the totality of all matter and energy — everything that is, was, and will be.
- Astronomy = the study of stars, planets and space. Astrology = the study of the movement of stars. Cosmology = the study of the universe — how it began, what it is made of, and how it continues to evolve and change.
- Our address, in order: Universe → Galaxy (Milky Way) → Solar System → Earth → Asia → South Asia → Pakistan.
The theories of how the universe began
| Theory | Says |
|---|---|
| Creation Theory | The universe was made by God/Allah |
| Oscillating Theory | The universe continuously expands and contracts |
| Static / Steady State Theory | The universe has had no change since it began |
| Big Bang Theory | Most accepted. Proposed by Georges Lemaître: a tiny, immensely dense point stored so much energy that it exploded — and the universe came into being, 13.8 billion years ago |
- The evidence for the Big Bang that papers ask: the CMB — cosmic microwave background — the afterglow of the explosion, still detectable today. If the options offer 13.7 billion years instead of 13.8, tick the figure in the options (see Traps).
- The banks ask who proposed the Big Bang and answer Georges Lemaître — learn the name with the theory, not apart from it.
Big Bang vs Pangaea — do not merge them
- Big Bang = the whole universe. Pangaea = Earth only — all the continents were once one landmass; they broke apart and drifted.
- The evidence for Pangaea: Africa’s and South America’s coasts fit together, and the same species, rocks, mountain ranges and minerals appear on both sides of the Atlantic.
- India broke off, drifted through the ocean and collided with Asia — and the Himalayas formed from that collision.
- The continents still move: South America drifts about 3.2 cm per year.
2. Stars, galaxies and black holes
Stars
- A star is a luminous body of hot gas, shining by its own energy. The Sun is a star — and it is the nearest star to the Earth (the banks ask this directly).
- The brightest star in the night sky is Sirius. The Pole Star is always seen at one point in the sky because it lies in the axis of the Earth’s spin — the other stars appear to move around it.
- A constellation is a group of stars. The Southern Cross is a constellation of 5 stars. The twelve constellations referred to as the zodiac are likewise a group of stars.
- A supernova is a huge star that dies and explodes, spreading light across the galaxy for weeks. When it goes fully dark and its energy ends, a black hole can form.
Galaxies — and ours
- Our galaxy is the Milky Way — the galaxy to which the solar system belongs. Its shape is spiral (the banks ask the shape repeatedly — five Milky Way shape questions in the site banks alone).
- The Milky Way extends through a distance of about 100,000 light years (the banks’ figure, “10 to the power 5 light years”).
- The nearest galaxy to the Milky Way is Andromeda, also spiral in shape — and the banks ask which galaxy Andromeda is colliding with, answering the Milky Way.
- At the centre of the Milky Way sits the black hole Sagittarius A*.
Black holes
- The concept of the black hole was first given by Albert Einstein in 1916, through the theory of relativity; the first black hole was seen in 1971.
- A black hole’s gravity is so strong that even light cannot escape — whatever goes in never returns: the point of no return. The banks describe it as a body in space which does not allow any radiation to come out, because of its very high density and intense gravitational field.
- Black holes are found in the middle of galaxies.
- Stephen Hawking did major work on black holes; his book “A Brief History of Time” is asked by name, and he suffered from motor neurone disease (ALS) — both facts are asked.
- Trap warning: the “Black Hole” of Calcutta — the 1756 episode in which 146 English prisoners were confined and only 23 survived, under Siraj-ud-Daula — is a history question, not an astronomy one. If the question names a regime or prisoners, it is Calcutta; if it names light, gravity or space, it is the astronomical black hole (see Traps).
3. The Sun and the solar system
- The Sun is a star and holds 99.8% of the solar system’s mass — everything else together is only 0.2%.
- The Sun’s energy comes from fusion — hydrogen fusing into helium. The contrast papers love: atomic bomb = fission; hydrogen bomb = fusion.
- The Sun sits approximately at the centre of the solar system, and the planets travel with it through millions of stars in our galaxy. The path of the Sun amongst the stars is called the ecliptic.
The structure of the Sun — four layers
Core → Photosphere → Chromosphere → Corona.
- The highest temperature is in the Core — the banks put the Sun’s centre at 15 million degrees C.
- The average / surface temperature is about 5,500°C (the banks give the range 5,500–6,000°C).
- The outermost layer, the Corona, is what papers mean when they ask for the surface of the Sun — not the virus. Sun-spots are the cooler, dark areas that move about on the Sun’s surface.
The small bodies: asteroids, meteoroids, comets
- After the Big Bang, some bodies never became planets and formed belts: the Asteroid Belt (between Mars and Jupiter) and the Kuiper Belt (beyond Pluto — comets live here).
- Asteroids = big rocks (some planet-sized), orbiting in the belt. Meteoroids = small pieces — when two asteroids collide, the fragments are meteoroids. A meteor is the name for such a body after it enters the Earth’s atmosphere and burns as a ball of fire.
- Comets = icy balls of gas — the keyword is ice. Frozen in the Kuiper belt’s cold, they melt near the Sun and grow tails.
- A “shooting star” is not a star at all — it is a meteoroid, asteroid or comet entering the atmosphere at about 20 km per second.
Distances — the two units papers never stop asking
| Unit | Means | Value |
|---|---|---|
| Astronomical Unit (AU) | Mean Sun–Earth distance | 150 million km (1 AU) |
| Light year | Distance light travels in vacuum in one year | 9.5 trillion km (the banks’ figure: 9.46 trillion km) |
- A light year is a unit of distance — never of time. The banks ask this six ways, and the answer is “distance” every time.
- Sunlight reaches the Earth in 8.2 minutes (8 minutes 20 seconds). One Astronomical Unit is the average distance between the Earth and the Sun.
4. The planets — the master table
The order, with the lecturer’s trick: My Very Educated Mother Just Served Us Noodles → Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune.
- The first four are the inner planets — all rocky. The next four are the outer planets — all gaseous.
- The moon-count chain the lecturer drills: Mercury 0 – Venus 0 – Earth 1 – Mars 2 … Jupiter 95 – Saturn 146 – Uranus 29 – Neptune 16.
| Planet | The facts papers ask |
|---|---|
| Mercury | Closest to the Sun; 0 moons; fastest revolution — 88 days; also the smallest planet (the banks ask smallest diameter and answer Mercury) |
| Venus | Hottest planet (its longest rotation — 243 days — leaves one side baking in the Sun); brightest planet; Morning Star and Evening Star (visible with the naked eye); 0 moons; rotates in the opposite direction to the other planets (retrograde) — which is why the Sun rises in the west and sets in the east there (a bank question); 95% carbon dioxide in its atmosphere; the Earth’s near twin |
| Earth | 3rd from the Sun (between Venus and Mars); 5th biggest planet; only planet with life; Blue Planet; shape = geoid; radius 6,378 km — measured by Al-Biruni at Nandana Fort (Dina) centuries ago as 6,338 km (6,378 − 40); if 6,378 is not in the options, tick 6,400; mass 6 × 10²⁴ kg; 1 moon — Luna; sunlight reaches Earth in 8.2 minutes; Earth began 4.6 billion years ago; the dinosaurs were wiped out by meteorites; gravity on the Moon is 1.6 m/s² against Earth’s 9.8 m/s² |
| Mars | 2 moons; smaller than Venus and Earth; named after the God of War; Red Planet; signs of water and valleys (valleys form where rivers cut through rock) — a future-home candidate; the banks ask on which planet besides Earth water is present, and answer Mars |
| Jupiter | Fastest rotation — 9.9 hours; 11× bigger than Earth; 95 moons (the lecturer’s figure); the Great Red Spot; storms on it; “Bodyguard of Earth” — its gravity holds the asteroid belt so rocks do not hit the inner planets |
| Saturn | Most moons — 146 (updated 2023; for old-data papers, tick 92 if 146 is not there); famous rings — one bank question describes a planet with three rings of swarming particles and answers Saturn |
| Uranus | 29 moons (older books print 27); Green Planet |
| Neptune | 16 moons; coldest planet (farthest from the Sun); takes the longest time to go once around the Sun (the banks ask this and answer Neptune) |
| Pluto | Not a planet since 2006 — a dwarf planet; snow-capped mountains are on Pluto (asked); the Kuiper Belt lies beyond it; of the eight planets known in Kepler’s lifetime, the banks count 6 |
- Moon-count caution (see Traps): moon counts are revised as astronomers find new moons, so papers of different eras print different figures. Saturn’s 146 (2023) replaced 92; Uranus’s 29 replaced 27. Always tick the figure that is in the options — the paper’s own era decides.
- Old-data trap: one bank question asks which planet has the largest number of satellites and answers Jupiter — that was true when the paper was set. On a current paper, Saturn’s 146 is the answer. The question’s options decide (see Traps).
5. The Moon and the sky
- Moonlight reaches the Earth in about 1.3 seconds.
- The Moon’s phases: the new moon is the phase when all sunlight passes to Earth and the Moon becomes invisible. The Moon takes about 28 days to return to the same position among the constellations (the banks’ figure).
- First man on the Moon: Neil Armstrong — the banks call the moon-landing one of the important incidents of the 20th century and ask who first set foot there.
- No light → the sky looks black (asked). A clear daytime sky looks blue because blue light is scattered more than red — the two sky questions are different questions: black is the sky with no light (space, night), blue is the scattering of daylight (see Traps).
- Great Bear = a group of 7 stars shaped like a bear; in Urdu Dubb-e-Akbar. A constellation is a group of stars.
- Great Bear Lake is in Canada; plain Bear Lake is in the USA — the lecturer’s self-correction, and the banks ask the lake’s country five ways, answering Canada every time. Do not let the lake steal the constellation’s answer (see Traps).
6. Eclipses, seasons and the Earth’s motions
Eclipses — the two orders
- Solar eclipse = S–M–E (Sun → Moon → Earth): the Moon comes between the Sun and the Earth. The banks ask the relative positions and answer: the Moon in between the Sun and the Earth.
- Lunar eclipse = S–E–M (Sun → Earth → Moon): the Earth comes between the Sun and the Moon. The Moon shines only by reflected sunlight, so it darkens. A lunar eclipse occurs on a full moon.
- Eclipse prayers (the Islamiat overlap): Kusuf = prayer at the sun eclipse; Khusuf = prayer at the moon eclipse. Trick: Khusuf = chand (moon) — the “kh” word goes with the moon. The banks ask when Namaz-e-Kusuf is offered and answer: at the time of the eclipse of the sun.
Revolution vs rotation
- Revolution = going around a body (a stone tied to a rope, swung around your hand). Rotation = spinning on your own point (a spinning lattu/top).
- Earth’s revolution: 365 days 6 hours → makes the seasons. The 6 hours pile up for 4 years → a leap year (years divisible by 4: 2024, 2028). The banks state it plainly: the Earth’s motion round its axis once in 24 hours is rotation, its motion round the Sun once in approximately 365 days is revolution.
- Earth’s rotation: 23 hours 56 minutes (about 24 hours) → makes day and night.
Equinox vs solstice
- Equinox = equal (from “equal”): day and night are equal — 21 March and 23 September. The banks ask what an equinox is and answer: the date when days and nights have an equal duration.
- Solstice = unequal: 21 June = longest day / shortest night; 21 December = longest night / shortest day. The banks define solstice as “the Sun stands still”.
Aphelion vs perihelion — the counter-intuitive pair
- Earth’s orbit is not a perfect circle: the far point is 152 million km, the near point 147 million km.
- Perihelion = near (“P = paas”) — 3 January. Aphelion = far — early July. The banks ask when the Earth is nearest to the Sun and answer early January.
- The counter-intuitive fact papers love: in winter (January) the Sun is NEARER the Earth — seasons come from the Earth’s tilt and revolution, not from its distance.
Master table — the Earth’s motions and dates
| Pair | Near / equal | Far / unequal |
|---|---|---|
| Rotation / Revolution | Rotation 23 h 56 m → day & night | Revolution 365 d 6 h → seasons |
| Equinox / Solstice | Equinox 21 Mar & 23 Sep → day = night | Solstice 21 Jun (longest day) & 21 Dec (longest night) |
| Perihelion / Aphelion | Perihelion 3 Jan, 147 million km | Aphelion early Jul, 152 million km |
6A. Retrospective — the 2025 space year (origin year 2025)
2025 was a launch-heavy year, and papers built from it ask the same way every year: which satellite, which country, which rocket, which date. Learn the table as a chain — Pakistan’s trio first, then the world’s — and every “which satellite in 2025” question answers itself. All rows are dated 2025; nothing here is a plan or a standing mission (plans are marked as plans below the table).
| Date (2025) | Event | The exam fact |
|---|---|---|
| 17 January | Pakistan — PRSC-EO1 launched from Jiuquan, China | Pakistan’s first indigenous electro-optical satellite; the first of the 2025 trio (full firsts treatment in GK-08 Section 4A, not duplicated here) |
| 2 February (images; announced August) | Uranus gains a 29th moon — S/2025 U1, found by the James Webb Space Telescope (NIRCam) | ~10 km across, between the orbits of Ophelia and Bianca; this is why the chapter’s Uranus count is 29, not 27 or 28 |
| 29 June (JST; 28 June EDT) | Japan — GOSAT-GW (IBUKI GW) on the 50th and final H-2A flight, from Tanegashima | Greenhouse gases + water cycle (TANSO + AMSR instruments); H-2A retires after 50 flights, 2001–2025, replaced by H3 |
| 1 July | 3I/ATLAS discovered by the ATLAS survey telescope, Chile | The third interstellar object ever found (after 1I/ʻOumuamua 2017 and 2I/Borisov 2019); closest approach to the Sun 29 October 2025 |
| 23 July | NASA — TRACERS, twin satellites on a Falcon 9 from Vandenberg | Tandem Reconnection and Cusp Electrodynamics Reconnaissance Satellites — solar wind entering Earth’s magnetosphere through the polar cusps |
| 25 July | Iran — Nahid-2 on a Russian Soyuz from Vostochny | Telecommunications satellite, 110 kg, Ku-band, five-year design life |
| 30 July | NISAR — NASA + ISRO, on GSLV-F16 from Sriharikota | NASA-ISRO Synthetic Aperture Radar — L-band (NASA) + S-band (ISRO), 12-metre reflector, Earth surface change every 12 days |
| 31 July | Pakistan — PRSC-S1 (KS-1) on a Kuaizhou-1A from Xichang, China | Earth-observation satellite; the second of the 2025 trio |
| 7 September | Total lunar eclipse (S–E–M), visible across Asia, Australia, Africa and Europe | A full moon eclipse — the chapter’s Section 6 order, now with a 2025 date attached; totality on the night of 7–8 September |
| 19 October | Pakistan — HS-1, first hyperspectral satellite, on a Kinetica-1 from Jiuquan | Hundreds of narrow spectral bands (not a few broad colours) — crops, soil moisture, water quality, deforestation, floods and landslides; the third of the 2025 trio |
| 14 November | Shenzhou-20 crew returns — aboard Shenzhou-21, from Tiangong | Return due 5 November was scrapped after a debris strike cracked the Shenzhou-20 capsule’s viewport window; Chen Dong, Chen Zhongrui and Wang Jie came home in the newly arrived Shenzhou-21 after 204 days |
| 28 December | Iran — Paya + Zafar-2 (+ upgraded Kowsar) on a Soyuz from Vostochny | Triple launch; the bank’s February file dates this “2 February” — corrected here to 28 December (see Section 9) |
Plans announced in 2025, not launches — do not file them as launches: NASA announced plans to build a lunar nuclear reactor (Fission Surface Power) by 2030; Pakistan’s rover is to fly on China’s Chang’e-8, planned for 2028 — the bank’s December wording “step on the Moon in 2026” is not taught (see Section 9).
Companion practice: the 15 CA-bank rows behind this table (script hidden_files/goldmine-notes-count-eds01-2025space.py — 51 pattern hits over 17 CA files / 2,012 questions, 15 genuine 2025 rows cited) serve as this section’s practice set; the chapter’s bankCount stays 81 — the 2025 rows are this year’s exam material, not yet in the past-paper banks.
7. Rapid-fire one-liners
- Universe = totality of all matter and energy; Astronomy = stars, planets, space; Astrology = movement of stars; Cosmology = how the universe began, what it is made of, how it evolves.
- Big Bang = most accepted; Georges Lemaître; 13.8 billion years ago; evidence = CMB.
- Pangaea = Earth only; continents were one; Himalayas from India hitting Asia; South America moves 3.2 cm/year.
- Black hole concept = Einstein, 1916; first seen 1971; even light cannot escape; found in galaxy centres.
- Stephen Hawking = black-hole work; “A Brief History of Time”; motor neurone disease (ALS).
- Our galaxy = Milky Way, spiral; its central black hole = Sagittarius A*; nearest galaxy = Andromeda.
- Supernova = dying star explodes, lights the galaxy for weeks, then becomes a black hole.
- Sun = a star; 99.8% of the solar system’s mass; energy = fusion (hydrogen → helium); atomic bomb = fission; hydrogen bomb = fusion.
- Planet order = My Very Educated Mother Just Served Us Noodles; inner = rocky; outer = gaseous.
- Asteroid Belt = between Mars and Jupiter; Kuiper Belt = after Pluto (comets).
- Asteroids = big rocks; Meteoroids = small fragments from asteroid collisions; Comets = icy gas balls.
- Shooting star = a meteoroid/asteroid/comet at ~20 km/sec, not a star.
- Sun’s structure = Core → Photosphere → Chromosphere → Corona; hottest part = Core (15 million °C); average/surface = 5,500°C.
- Sun–Earth distance = 150 million km = 1 AU; light year = 9.5 trillion km (banks: 9.46); light year = unit of distance.
- Revolution = around a body (seasons); Rotation = on own axis (day/night); Earth revolution = 365 days 6 hours; rotation = 23 h 56 m.
- Leap year = years divisible by 4 (2024, 2028).
- Mercury = closest; 0 moons; 88-day revolution (fastest); smallest.
- Venus = hottest; brightest; Morning & Evening Star; naked-eye visible; 243-day rotation; 0 moons; retrograde (Sun rises in the west).
- Earth = 3rd from Sun; 5th biggest; only life; Blue Planet; geoid; radius 6,378 km (Al-Biruni 6,338 km, Nandana Fort; fallback 6,400); mass 6 × 10²⁴ kg; moon Luna.
- Sunlight reaches Earth = 8.2 minutes; Earth began = 4.6 billion years ago; Moon’s g = 1.6 m/s² (Earth’s 9.8); first man on the Moon = Neil Armstrong.
- Jupiter = fastest rotation 9.9 h; 11× Earth; 95 moons; red spot; storms; Bodyguard of Earth.
- Saturn = most moons, 146 (old data: 92); rings; Uranus = 29 moons; Green Planet; Neptune = 16 moons; coldest; longest revolution.
- Pluto = not a planet since 2006; snow-capped mountains.
- Mars = 2 moons; God of War; Red Planet; water/valley signs.
- Moonlight reaches Earth = ~1.3 seconds; new moon = invisible phase; Moon returns among constellations in 28 days.
- Great Bear = 7 stars (Dubb-e-Akbar); Constellation = group of stars; Great Bear Lake = Canada; Bear Lake = USA.
- Solar eclipse = S–M–E; Lunar eclipse = S–E–M (full moon); Kusuf = sun-eclipse prayer; Khusuf = moon-eclipse prayer.
- Equinox (equal) = 21 March & 23 September; Solstice (unequal) = 21 June (longest day), 21 December (longest night).
- Perihelion (near) = 3 January, 147 million km; Aphelion (far) = early July, 152 million km.
- 2025 space year = PRSC-EO1 (17 Jan, Jiuquan) → S/2025 U1, Uranus’s 29th moon (2 Feb, Webb) → GOSAT-GW, H-2A’s 50th and final flight (29 Jun) → 3I/ATLAS, third interstellar object (1 Jul) → TRACERS twins (23 Jul) → Nahid-2 (25 Jul) → NISAR, NASA+ISRO (30 Jul) → PRSC-S1/KS-1 (31 Jul) → total lunar eclipse (7 Sep) → HS-1, Pakistan’s first hyperspectral (19 Oct) → Shenzhou-20 crew home in Shenzhou-21 (14 Nov) → Paya + Zafar-2 (28 Dec).
8. Most-asked facts (from our verified past-paper banks)
- Sun & solar system — 24 questions: the light year as a unit of distance (asked six ways, answered “distance” every time) and its value (9.46 trillion km); one Astronomical Unit = the Earth–Sun distance; the Sun’s centre at 15 million °C against a 5,500–6,000°C surface; Sun-spots as dark cooler areas; the Sun at approximately the centre of the system; the meteor defined by entering the atmosphere; and Venus as the planet where the Sun rises in the west.
- Planets — 16 questions: Venus as Morning and Evening Star (asked three ways), Venus’s 95% carbon dioxide and Earth’s near twin; Jupiter’s Great Red Spot (asked twice) and the old-data “largest number of satellites = Jupiter” question; Neptune’s longest revolution; Mercury smallest and nearest; Earth third, between Venus and Mars; Mars water; and Pluto no longer a planet.
- Universe, stars & black holes — 15 questions: the Milky Way’s spiral shape (asked five ways); Andromeda’s collision with the Milky Way; Big Bang proposed by Lemaître; “A Brief History of Time” by Stephen Hawking; what a black hole is (no radiation escapes; very high density; intense gravitational field); Sirius, brightest star in the night sky; and the nearest star to Earth = the Sun.
- Moon & sky — 14 questions: Great Bear Lake in Canada (asked five ways — the lake, not the stars); the constellation of seven bright stars = the Great Bear; the Southern Cross = 5 stars; moonlight in 1.3 seconds; Neil Armstrong, first man on the Moon; and the clear sky blue because blue light is scattered more than red (asked twice).
- Eclipses & motions — 12 questions: the solar eclipse order (Moon between Sun and Earth) asked three ways; Namaz-e-Kusuf at the sun’s eclipse (asked twice); lunar eclipse on a full moon; equinox = equal day and night (asked three ways); rotation (24 hours) vs revolution (365 days); Earth nearest the Sun in early January; and solstice = “the Sun stands still”.
- 2025 space year (Section 6A, origin year 2025, no 🔁/⭐ claimed for the table itself — one year only): the Pakistan trio is the most askable block — EO-1 (January, electro-optical, Jiuquan), KS-1/PRSC-S1 (July, Xichang), HS-1 (October, hyperspectral, Jiuquan) — followed by NISAR (NASA+ISRO, 30 July) as the joint-mission question, 3I/ATLAS (third interstellar object) as the comet question, and S/2025 U1 (Uranus 29) as the moon-count question. Companion practice: the 15 CA-bank rows behind Section 6A.
- Taught from the lecture and capsule, no direct site-bank question-text match: the four universe theories in full, Pangaea’s evidence chain, the Sun’s four layers in order, the asteroid/meteoroid/comet distinctions, the planet order mnemonic, the full moon-count chain, the Earth-structure figures (carried to Chapter 2), and the eclipse-prayer trick Khusuf = chand — the lecture teaches these at full depth, and the practice set is filtered by tags at serve time.
9. Traps & confusions
- Black Hole (space) vs Black Hole (Calcutta): the astronomical black hole traps light and gravity; the Calcutta “Black Hole” trapped 146 prisoners, 23 survived, under Siraj-ud-Daula. The question’s nouns decide — regime/prisoners = Calcutta; light/gravity/space = astronomy.
- “Miss Universe” is not the universe: one bank question uses “Miss Universe pageant” as an English vocabulary item — it is not an astronomy question at all.
- Moon counts move with the era: Saturn 146 (2023) vs 92 (old); Uranus 29 vs 27 (old); Jupiter’s “largest number of satellites” answer belongs to the paper’s era. Always tick the figure in the options — never import a newer count into an old paper’s options, or vice versa.
- Great Bear (stars) vs Great Bear Lake (Canada): the constellation is 7 stars; the lake is in Canada. Papers ask “What is ‘Great Bear’?” and answer Lake when the question is about the lake — read whether the question asks about stars or a place.
- Black sky vs blue sky: the sky looks black where there is no light (space, and the lecture’s point); a clear daytime sky looks blue because blue light is scattered more than red. Same sky, two questions, two mechanisms.
- Big Bang 13.8 vs 13.7: both figures circulate; 13.8 is the chapter’s figure and the lecturer’s. If the options print 13.7, tick 13.7 — the paper’s options decide.
- Earth radius 6,378 vs 6,400 vs Al-Biruni’s 6,338: 6,378 km is the standard; 6,400 is the fallback if 6,378 is absent; 6,338 km is Al-Biruni’s historic measurement at Nandana Fort — asked as a separate “who measured it / what did he get” question.
- Corona vs virus: when a paper asks for the surface of the Sun, the answer is the Corona — the Sun’s outer layer, not the disease.
- Perihelion in winter: the Earth is nearest the Sun in January, in winter — seasons come from tilt, not distance. If a question argues “winter because the Sun is far”, it is wrong.
- Venus’s rotation: Venus spins backwards compared with the other planets — that is why its Sun rises in the west. Do not answer “east to west” for Venus’s sunrise.
- Pluto is not the ninth planet any more: any question still calling Pluto a planet is using pre-2006 framing; since 2006 it is a dwarf planet.
- Uranus 29 — and how the count got there: Uranus had 27 moons, then S/2023 U1 (announced 2024) made 28, then S/2025 U1 (Webb images 2 February 2025, announced August 2025) made 29. A paper printing 27 or 28 is using pre-2025 framing; a 2025-or-later paper prints 29.
- Paya + Zafar-2 — the bank’s date is wrong: the February CA file dates this launch “2 February 2025”; the launch actually flew 28 December 2025 (Soyuz, Vostochny, with upgraded Kowsar). Do not learn the February date.
- Shenzhou-20 vs Shenzhou-21 — who flew home in what: the crew that returned on 14 November 2025 was the Shenzhou-20 crew (Chen Dong, Chen Zhongrui, Wang Jie); the vehicle they returned in was the newly arrived Shenzhou-21. The bank’s wording (“astronauts made an emergency return”) hides that swap — learn crew and vehicle separately.
- Chang’e-8 — 2028, not 2026: Pakistan’s rover flies on China’s Chang’e-8, planned for 2028. The bank’s December row (“step on the Moon in 2026”) conflates the mission with a 2026 date and is not taught.
- Held, not taught from the CA bank’s space rows: the Perseverance “Mars lightning” November 2025 row (no corroborating source found in this check), the Israel Ofek-series SAR row (no satellite name or date in the row), the Chiron ring-formation row (unverified in this check), the China deepwater “space station” row (a plan reported in February 2025, not a built station), the Russia “100 satellites” row (unverified), and the Starlink Pakistan registration row (telecom policy, not space science). The 2026 space rows in the same files (Artemis II/V, EO-3, LUPEX, Shenzhou-23) belong to the 2026 retrospective, not this one.
- Light year is distance, not time: the single most repeated trap in this chapter — “light year” measures distance, however much it sounds like a year.
10. Memory tricks (lectures first, then clean professional hooks)
- My Very Educated Mother Just Served Us Noodles: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune — the lecturer’s order trick, and the only one you need for the planet questions.
- S–M–E, S–E–M: solar eclipse puts the Moon in the Middle; lunar eclipse puts the Earth in the middle. The middle letter is the body doing the blocking.
- Khusuf = chand: the eclipse prayer with “kh” belongs to the moon (chand) — Kusuf, without it, belongs to the Sun.
- P = paas (near): Perihelion = the Paas (near) point, 3 January; Aphelion = Away, early July.
- Equinox = equal: the word itself gives the answer — equal day and night, 21 March and 23 September.
- Moon-count chain 0–0–1–2: Mercury 0, Venus 0, Earth 1, Mars 2 — say it as a chain and the inner planets’ moons are locked; then 146 for Saturn, the current record-holder.
- 99.8% Sun: the Sun is not just the biggest body in the solar system — it is the solar system, by mass. Everything else combined is 0.2%.
- 100,000 light years across, spiral in shape: the Milky Way’s two bank facts in one line — its shape (spiral) and its span (10⁵ light years).
- 13.8 and 4.6: the universe is 13.8 billion years old, the Earth 4.6 billion — the two ages, three digits apart in the same chapter, never swap them.
- 2025 space ladder — E-K-H: Pakistan’s trio in order — EO-1 (January, electro-optical), KS-1 (July, remote sensing), HS-1 (October, hyperspectral) — then the world trio in the same month: NISAR ends July, eclipse opens September, Shenzhou swap closes November.
11. Visuals (site build specs)
- DIAGRAM — The solar system in order: a scaled schematic (not to scale, labelled as such) showing the Sun at the centre, the eight planets in order with the inner-rocky / outer-gaseous split marked, the Asteroid Belt between Mars and Jupiter, and the Kuiper Belt beyond Pluto — placed in Section 4 as the chapter’s orientation graphic.
- DIAGRAM — The Sun’s four layers: a cutaway from Core → Photosphere → Chromosphere → Corona, with the centre temperature (15 million °C) and surface temperature (5,500°C) labelled — placed in Section 3.
- DIAGRAM — The two eclipses: side-by-side S–M–E (solar) and S–E–M (lunar) panels, with the full-moon condition marked on the lunar panel — placed in Section 6.
- INFOGRAPHIC — The Earth’s year: a circular year-diagram marking perihelion (3 January), the March equinox, the June solstice, aphelion (early July), the September equinox and the December solstice, with the tilt-not-distance note — placed after Section 6.
- TABLE-GRAPHIC — The planet table: the Section 4 master table rendered as a swipeable table (planet, moons, one-line fact) for last-night revision — placed in Section 4.
- TIMELINE — The 2025 space year: a horizontal year-timeline of the Section 6A table (January EO-1 → December Paya/Zafar-2), with the Pakistan trio in one colour and the world launches in another, and the two plans (NASA lunar reactor, Chang’e-8 2028) shown dashed, not solid — placed in Section 6A.
12. Practice this topic
- Practice set: 81 verified past-paper questions in the PPSC + FPSC banks are tagged to this topic’s sub-topics (universe & stars & black holes 15, Sun & solar system 24, planets 16, Moon & sky 14, eclipses & motions 12) — the site serves them as this chapter’s practice set, with the IBES Everyday Science capsule questions behind them. Companion practice for Section 6A: the 15 gk360 monthly CA-bank rows behind the 2025 space-year table (script hidden_files/goldmine-notes-count-eds01-2025space.py). Note for the build: the practice set is filtered by the topic’s subject+topic tags at serve time, so the Great Bear Lake questions counted in the Moon & sky bucket also serve the Pakistan/World Geography revision, and the old-data Jupiter-satellites question is served with its era’s answer.
- Book mode: ← Previous: Islamic Months, Worship & Society · Next: Earth & Its Spheres (Everyday Science) →
Goldmine Notes · Everyday Science · Chapter 1 · Sources: EDS Lecture 1 (Universe, Solar System & Planets — detailed notes, rechecked); verified PPSC/FPSC past-paper banks (81 topic questions, script-counted, hidden_files/goldmine-notes-count-eds01.py); IBES Everyday Science capsule bank behind the chapter (universe creation facts, basic physics); standard-reference web check for aphelion timing (early July; perihelion 3 January). Section 6A sources: gk360 monthly CA bank (17 files / 2,012 questions, script hidden_files/goldmine-notes-count-eds01-2025space.py — 15 genuine 2025 rows cited) + standard-reference web checks for each dated row (NASA/ISRO NISAR 30 July 2025; SUPARCO HS-1 19 October 2025 and PRSC-S1 31 July 2025; NASA Webb S/2025 U1 images 2 February 2025, announced August 2025; ATLAS 3I/ATLAS 1 July 2025; NASA TRACERS 23 July 2025; JAXA GOSAT-GW 29 June 2025, 50th/final H-2A; Iran Nahid-2 25 July 2025 and Paya/Zafar-2 28 December 2025, Soyuz/Vostochny; Shenzhou-20 crew return 14 November 2025 aboard Shenzhou-21; total lunar eclipse 7 September 2025). Standard answers only.