[{"data":1,"prerenderedAt":815},["ShallowReactive",2],{"layer:eclipses:extend":3},{"layer":4,"contentHash":794,"dependencyHashes":795,"approval":808,"releaseId":814},{"schemaVersion":5,"conceptId":6,"locale":7,"depth":8,"revision":5,"title":9,"subtitle":10,"summary":11,"objectives":12,"estimatedMinutes":18,"plate":19,"blocks":43,"sourceIds":789,"reviewStatus":790,"authoring":791},1,"eclipses","en","extend","The same shadow rule, everywhere in the Solar System","Moons too small to eclipse, a moon that eclipses constantly, transits at home, and other worlds' planets","Take the eclipse geometry beyond Earth: why Phobos and Deimos only ever transit the Sun from Mars, why Io causes true eclipses on Jupiter routinely, how Mercury and Venus transit the Sun from Earth, Venus's 243-year transit rhythm, and how the same trick finds other stars' planets.",[13,14,15,16,17],"Compare a crossing body's angular size with the Sun's to decide whether it can ever cause a total eclipse or only a transit.","Explain why Io causes routine total eclipses on Jupiter while Phobos and Deimos can only transit the Sun from Mars.","Calculate a transit's light-dip percentage from the crossing body's width ratio, and apply the same method to an exoplanet.","Explain the 8-year-pair, 243-year Venus transit cycle and its historical use for measuring the astronomical unit.","Pose and reason through an open puzzle about eclipse geometry, using computed angular sizes to support an argument.",40,{"title":20,"rows":21},"Lesson plate",[22,25,28,31,34,37,40],{"label":23,"value":24},"Depth","Extend",{"label":26,"value":27},"Reading time","≈ 40 minutes",{"label":29,"value":30},"Prior knowledge","Angular size and the 400-coincidence (Discover, Understand)",{"label":32,"value":33},"Chapters","10",{"label":35,"value":36},"Labs","Sort game, match-pairs",{"label":38,"value":39},"Goes beyond NCERT","Yes — other planets' moons and exoplanets",{"label":41,"value":42},"Safety","Same rules apply to any Sun, anywhere",[44,50,56,62,65,78,83,109,127,132,137,149,154,203,208,211,234,245,250,255,260,279,290,294,299,302,320,331,336,362,367,370,374,378,402,415,426,431,434,438,442,456,481,494,499,510,530,535,538,543,546,571,575,578,583,597,603,639,761,777],{"id":45,"type":46,"markdown":47,"help":48},"e-intro","prose","Everything in this topic so far has been about one particular Sun, one particular Moon and one particular Earth. But the rule behind an eclipse is not special to us: **any moon, orbiting any planet, lit by any star, casts a shadow — and that shadow can land on its own planet, on a neighbouring moon, or nowhere at all.**\n\nThis layer takes the same geometry everywhere else in the Solar System, and a little beyond it: to two moons too small to ever cover the Sun, to a moon whose shadow makes a true eclipse on a giant planet's clouds every few days, to two planets that only ever cross the Sun's face as tiny dots, and to the same tiny-dot idea used to find planets around *other* stars entirely.",{"simplerExplanation":49},"The eclipse rule works everywhere: a moon's shadow, whichever planet it belongs to, still needs to be big enough and land in the right place.",{"id":51,"type":52,"variant":53,"title":54,"markdown":55},"e-safety-recap","callout","careful","Still true everywhere in this layer","None of what follows changes the rule from every earlier layer: **never look at the Sun directly without certified filters, from Earth or in your imagination of any other world.** Every number here was worked out from orbital data, not from anyone standing on Mars or Jupiter with a telescope pointed at the Sun.",{"id":57,"type":58,"title":59,"eyebrow":60,"navLabel":61},"e-ch1","chapter","Mars: two moons, no total eclipse ever","Chapter 01","1 Mars's moons",{"id":63,"type":46,"markdown":64},"e-mars-intro","Mars has two moons, Phobos and Deimos, both tiny, lumpy, potato-shaped rocks captured long ago rather than formed neatly like our Moon. Phobos orbits closer to Mars than any large moon orbits any other planet in the Solar System — only about 6,000 km above the surface. Deimos is smaller and further out, at about 20,000 km.",{"id":66,"type":67,"title":68,"problem":69,"steps":70,"help":76},"e-we-phobos","worked_example","Could Phobos ever black out the Sun from Mars?","Phobos is about 22.5 km across and orbits only 6,000 km above Mars's surface. The Sun, seen from Mars (1.524 AU out), looks about 0.350° across. How big does Phobos look from the Martian surface, and is it bigger or smaller than the Sun?",[71,72,73,74,75],"Angular size of Phobos ≈ 57.3 × 22.5 ÷ 6,000 = **0.215°**.","Angular size of the Sun from Mars ≈ 57.3 × 1,392,700 ÷ (1.524 × 149,597,871) = **0.350°**.","Compare: 0.215° is only about **61%** of 0.350°. Phobos looks noticeably **smaller** than the Sun, every single time, from anywhere on Mars.","**Conclusion:** Phobos can never produce a total eclipse on Mars. Every solar 'eclipse' caused by Phobos is really a **transit** — a small dark dot crossing part of the Sun's face, covering at most about 37% of its width and roughly (0.61)² ≈ 37% of its area at best, and usually less because Phobos rarely crosses dead centre.","Phobos does this often, though: because it orbits so close and so fast (about 7 hours 39 minutes per orbit, faster than Mars itself spins), it transits the Sun several times per Earth year from many locations on Mars — recorded many times by the Mars rovers.",{"simplerExplanation":77},"Phobos looks only about 61% as wide as the Sun from Mars, so it can only ever nibble a dark dot out of the Sun's face — never black it out completely.",{"id":79,"type":52,"variant":80,"title":81,"markdown":82},"e-example-rovers","example","Photographed from the ground, on another world","NASA's Mars rovers — Spirit, Opportunity, Curiosity and Perseverance among them — have photographed Phobos transiting the Sun many times, using solar filters on their cameras exactly as a careful observer would on Earth. The images show a small, dark, distinctly non-circular dot (Phobos is lumpy, not round) sliding across part of the Sun's disc in under a minute, because Phobos orbits so fast and so close.",{"id":84,"type":85,"caption":86,"columns":87,"rows":94},"e-table-moons","table","Phobos and Deimos: could either ever cause a total eclipse?",[88,89,90,91,92,93],"Moon","Width","Altitude","Angular size","vs Sun (0.350°)","Verdict",[95,102],[96,97,98,99,100,101],"Phobos","22.5 km","≈6,000 km","≈0.215°","61% as wide","Transit only, fairly often",[103,104,105,106,107,108],"Deimos","12.4 km","≈20,000 km","≈0.036°","10% as wide","A barely-visible speck crossing the Sun",{"id":110,"type":111,"prompt":112,"options":113,"explanation":126},"e-predict-phobos-size","prediction","The worked example found Phobos needs to be about 63% bigger across, at its real altitude, to fully cover the Sun from Mars. If a future spacecraft somehow nudged Phobos much closer to Mars instead of making it bigger, could that achieve the same result?",[114,117,120,123],{"id":115,"label":116},"a","No — only physical size matters, not distance",{"id":118,"label":119},"b","Yes — moving Phobos closer increases its angular size, exactly as making it bigger would",{"id":121,"label":122},"c","No — Phobos would break apart before getting close enough",{"id":124,"label":125},"d","Yes, but only if Mars's orbit also changed","**Both (b) is the geometry, and (c) is also true in reality.** Angular size depends on real size **divided by distance**, so halving the distance has exactly the same effect on angular size as doubling the diameter — Phobos would not need to grow at all if it orbited close enough. In practice, though, Phobos is already drifting slowly **inward** due to tides, and models suggest it will break apart or crash into Mars in tens of millions of years, long before it could ever spiral in close enough to cover the Sun.",{"id":128,"type":58,"title":129,"eyebrow":130,"navLabel":131},"e-ch2","Jupiter: real eclipses, every few days","Chapter 02","2 Jupiter's moons",{"id":133,"type":46,"markdown":134,"help":135},"e-jupiter-intro","Now the opposite extreme. Jupiter's big moon **Io** is a genuine, roomy world 3,643 km across — bigger than our own Moon — orbiting only 421,700 km from Jupiter's cloud tops, closer relative to its size than our Moon is to Earth.",{"simplerExplanation":136},"Io is a proper large moon, close to Jupiter, so its shadow is a proper eclipse-making shadow, not a mere transit dot.",{"id":138,"type":67,"title":139,"problem":140,"steps":141,"help":147},"e-we-io","Io's shadow: transit dot, or true eclipse?","Jupiter, at 5.204 AU, sees the Sun at about 0.103° across — much smaller than we do, because Jupiter is so far out. Io is 3,643 km across, orbiting 421,700 km from Jupiter. How does Io's angular size compare with the Sun's, as seen from Jupiter's cloud tops?",[142,143,144,145,146],"Angular size of Io ≈ 57.3 × 3,643 ÷ 421,700 = **0.495°**.","Angular size of the Sun from Jupiter ≈ 57.3 × 1,392,700 ÷ (5.204 × 149,597,871) ≈ **0.103°**.","Ratio: 0.495 ÷ 0.103 ≈ **4.8**. Io looks nearly **five times wider** than the Sun, as seen from Jupiter's clouds.","**Conclusion:** Io does not merely transit the Sun — it utterly blots it out, casting a small, sharp, genuinely black shadow spot onto Jupiter's clouds below, visible even through amateur telescopes on Earth as it crosses. Because Io orbits Jupiter in only about 42 hours, its shadow crosses Jupiter's disc, and true 'eclipses' of the Sun by Io happen on Jupiter roughly once every Io orbit — far more often than on Earth.","The other three large Galilean moons — Europa, Ganymede and Callisto — do the same thing, each casting its own sharp shadow spot at its own rhythm, so Jupiter's clouds are almost never without some moon's eclipse shadow crawling across them.",{"simplerExplanation":148},"The Sun looks tiny and Io looks big from Jupiter, so Io's shadow is a small, sharp, totally black spot — a real eclipse, not just a transit dot, and it happens very often.",{"id":150,"type":52,"variant":151,"title":152,"markdown":153},"e-aha-jupiter","aha","Jupiter's moons are basically permanent eclipse machines","On Earth, the coincidence that makes total eclipses possible is delicate — the Moon is *only just* big enough, and the alignment is rare. On Jupiter, there is no such coincidence to worry about: **every** large Galilean moon is comfortably bigger, in the sky, than the tiny, distant Sun. Total eclipses on Jupiter are not a once-in-months event needing a special coincidence; they are closer to being the **default state** of the system, limited only by how often each moon's orbit lines it up with the Sun-Jupiter line — which, at Io's 42-hour orbital period, is often.",{"id":155,"type":156,"component":157,"componentVersion":5,"config":158,"objective":201,"textAlternative":202},"e-lab-sort-worlds","interactive","sort-game",{"prompt":159,"bins":160,"items":167,"seconds":200},"Sort each Solar System body's Sun-crossing event into the right box.",[161,164],{"id":162,"label":163},"eclipse","True eclipse (blots out Sun)",{"id":165,"label":166},"transit","Transit only (a dot)",[168,172,176,180,184,188,192,196],{"id":169,"label":170,"bin":162,"why":171},"w1","Io crossing in front of the Sun, seen from Jupiter","Io looks nearly 5 times wider than the tiny, distant Sun from Jupiter — total, every time.",{"id":173,"label":174,"bin":165,"why":175},"w2","Phobos crossing in front of the Sun, seen from Mars","Phobos looks only about 61% as wide as the Sun from Mars — always a partial dot.",{"id":177,"label":178,"bin":165,"why":179},"w3","Deimos crossing in front of the Sun, seen from Mars","Deimos looks only about 10% as wide as the Sun — a barely visible speck.",{"id":181,"label":182,"bin":162,"why":183},"w4","Our own Moon at perigee, new moon, near a node","Close enough to look bigger than the Sun — a real total solar eclipse.",{"id":185,"label":186,"bin":165,"why":187},"w5","Mercury crossing the Sun, seen from Earth","Mercury looks only about 0.66% of the Sun's width — a tiny dot, even through a telescope.",{"id":189,"label":190,"bin":165,"why":191},"w6","Venus crossing the Sun, seen from Earth","Venus looks about 3% of the Sun's width — a bigger dot than Mercury's, but still only a dot.",{"id":193,"label":194,"bin":162,"why":195},"w7","Europa crossing in front of the Sun, seen from Jupiter","Another large, close Galilean moon, easily wide enough to cover the tiny Jovian Sun.",{"id":197,"label":198,"bin":165,"why":199},"w8","Our Moon at apogee, new moon, near a node","Too far to cover the Sun fully — this is an annular eclipse, closer in spirit to a very large transit with a ring left over.",0,"Sort eight Sun-crossing events from across the Solar System into true eclipses and mere transits.","A sorting game with two boxes — true eclipse and transit only — and eight real examples: Io and Europa crossing the Sun from Jupiter (both eclipses); Phobos, Deimos, Mercury and Venus crossing from their respective vantage points (all transits); and our own Moon at perigee (eclipse) versus apogee (transit-like ring) as the two extremes of our own case.\n\nThe pattern to notice: it is always the same test — is the crossing body's angular size bigger or smaller than the Sun's, from where you are standing?",{"id":204,"type":58,"title":205,"eyebrow":206,"navLabel":207},"e-ch3","Transits at home: Mercury and Venus","Chapter 03","3 Mercury and Venus",{"id":209,"type":46,"markdown":210},"e-transits-intro","Earth has its own transits, caused by the two planets that orbit closer to the Sun than we do: Mercury and Venus. Neither can ever eclipse the Sun from Earth — they are too small and too far away — but both cross its face as dots, visible (with a proper solar filter) as a small, perfectly round, dark circle.",{"id":212,"type":85,"caption":213,"columns":214,"rows":219},"e-table-transits","Mercury and Venus, crossing the Sun as seen from Earth",[215,89,216,91,217,218],"Planet","Distance at transit","Share of Sun's width","Share of Sun's area (light dip)",[220,227],[221,222,223,224,225,226],"Mercury","4,879 km","≈0.53 AU","≈12.7″","≈0.66%","≈0.0000437%",[228,229,230,231,232,233],"Venus","12,104 km","≈0.288 AU","≈58.1″","≈3.03%","≈0.092%",{"id":235,"type":67,"title":236,"problem":237,"steps":238,"help":243},"e-we-transit-dip","How much does Venus dim the Sun during a transit?","Venus's disc is about 3.03% of the Sun's width during a transit. If you measured the Sun's total brightness precisely throughout the transit, by how much would it dip?",[239,240,241,242],"Brightness depends on the **area** blocked, not the width. Area scales as width squared.","Dip ≈ (3.03%)² relative to the whole disc's area = 0.0303² ≈ **0.00092**, or **0.092%**.","That is less than one part in a thousand — utterly undetectable to the naked eye (which is exactly why you must never try to detect it by looking directly at the Sun), but very measurable with a sensitive light meter, which is exactly the technique used to find planets around other stars.","Compare Mercury: (0.66%)² ≈ 0.0000437%, over twenty times smaller a dip than Venus's, because Mercury is both smaller and further from Earth at transit.",{"simplerExplanation":244},"Venus blocks about 0.092% of the Sun's light during a transit — a tiny but real dip, only detectable with instruments, never with the eye.",{"id":246,"type":52,"variant":247,"title":248,"markdown":249},"e-nuance-parallax","nuance","Why 18th-century astronomers cared so much about Venus transits","Deepen explained that the Sun's own parallax — about 8.78 arcseconds — is one of astronomy's hardest numbers to pin down directly, because it demands measuring an almost imperceptible shift. Venus transits gave astronomers a clever workaround: by timing exactly when Venus's black dot touched the Sun's edge, from several widely separated places on Earth at once, the small differences in timing could be turned into a measurement of the **Earth-Sun distance itself** — without ever measuring the Sun's parallax directly.\n\nEdmond Halley proposed the method; expeditions across the globe (including observers sent to India and the Indian Ocean) attempted it for the 1761 and 1769 transits. The results were messy — the \"black drop effect\", where Venus's disc seems to smear against the Sun's edge, limited the precision — but they gave the first serious, evidence-based estimate of the astronomical unit, decades before other methods caught up.",{"id":251,"type":58,"title":252,"eyebrow":253,"navLabel":254},"e-ch4","The strange rhythm of Venus transit pairs","Chapter 04","4 Venus's rhythm",{"id":256,"type":46,"markdown":257,"help":258},"e-venus-rhythm","Venus transits do not come at a steady interval. They arrive in **pairs**, eight years apart, and then nothing for over a century.",{"simplerExplanation":259},"Venus transits: two, eight years apart, then a huge gap, then two more.",{"id":261,"type":262,"items":263},"e-formula-venus","formulas",[264,267,270,273,276],{"expression":265,"caption":266},"Pair gap","8 years",{"expression":268,"caption":269},"Long gaps","105.5 or 121.5 years",{"expression":271,"caption":272},"Full cycle","8 + 105.5 + 8 + 121.5 = 243 years",{"expression":274,"caption":275},"Last pair","2004, 2012",{"expression":277,"caption":278},"Next pair","2117, 2125",{"id":280,"type":67,"title":281,"problem":282,"steps":283,"help":288},"e-we-venus-cycle","Why 243 years, and why pairs of two?","Venus transits happen only when Venus, at inferior conjunction (passing between Earth and the Sun), is also near one of its own orbital nodes — the same two-condition test as any eclipse. Given the pattern 8, 105.5, 8, 121.5 years repeating, confirm the cycle length and explain the pairing.",[284,285,286,287],"Add the four gaps: 8 + 105.5 + 8 + 121.5 = **243 years** exactly, a genuine long-period near-coincidence between Earth's and Venus's orbital periods (very close to 152 Earth years = 235 Venus years, and to other whole-number ratios).","The **pairing** happens because after 8 years, Venus and Earth return to nearly — but not exactly — the same relative arrangement, close enough that if a transit happened once, conditions are still good enough eight years later for the node alignment to repeat. After that, the small mismatch (much like the Saros mismatch in Deepen) has grown too large, and over a century must pass before the alignment returns.","**Confirmed:** last pair 2004 and 2012 (an 8-year gap); next pair 2117 and 2125, another 8-year gap — matching 2012 + 105 = 2117.","Nobody alive during the 2012 transit will see the next one in 2117 — a genuinely once-or-twice-in-several-lifetimes event, unlike almost anything else in this topic.",{"simplerExplanation":289},"8 + 105.5 + 8 + 121.5 = 243 years exactly. Transits come in pairs 8 years apart because the near-alignment barely survives a second try, then takes over a century to return.",{"id":291,"type":292,"prompt":293},"e-reflect-venus","reflection","The next Venus transit is in 2117. If you are 11 years old today (2026), work out roughly how old you would be in 2117, and decide whether you think you could plausibly see it. Then research (or estimate) how many people alive today are likely to see it, and how that compares with how many will see, say, the 2034 total solar eclipse crossing India.",{"id":295,"type":58,"title":296,"eyebrow":297,"navLabel":298},"e-ch5","The same trick, used to find planets around other stars","Chapter 05","5 Exoplanet transits",{"id":300,"type":46,"markdown":301},"e-exo-intro","Here is where this topic connects to one of the biggest ongoing projects in all of astronomy. If a tiny, precise dip in a star's brightness reveals a planet crossing in front of it — exactly the trick used for Venus and Mercury — then the same method, pointed at other stars, should reveal **their** planets too. It does, and it is now the single most productive method for discovering planets beyond our Solar System.",{"id":303,"type":85,"caption":304,"columns":305,"rows":309},"e-table-exo-dips","Comparing transit dips: from Mercury to a whole planet-sized world",[306,307,308],"Transiting body","Width vs Sun","Light dip",[310,311,312,316],[221,225,226],[228,232,233],[313,314,315],"Earth","≈0.917%","≈0.0084%",[317,318,319],"Jupiter","≈10.27%","≈1.05%",{"id":321,"type":67,"title":322,"problem":323,"steps":324,"help":329},"e-we-earth-dip","Could a distant civilisation detect Earth transiting the Sun?","Earth is about 12,742 km across; the Sun is 1,392,700 km across. What fractional dip in the Sun's brightness would Earth's transit cause, and is that within reach of a sensitive space telescope, which can typically detect dips as small as about 0.001%?",[325,326,327,328],"Width ratio: 12,742 ÷ 1,392,700 ≈ **0.00915**, or 0.915%.","Dip = (0.00915)² ≈ **0.0000837**, or about **0.0084%**.","0.0084% is bigger than the stated detection floor of 0.001%, by a factor of more than eight — so yes, a sufficiently sensitive telescope, aimed at the right moment as Earth crosses the Sun's face from that alien vantage point, could in principle detect an Earth-sized planet this way.","This is exactly the logic behind real missions such as Kepler and TESS: they stare at huge numbers of stars for years, waiting for a small, precise, repeating dip — and the size of the dip tells you the planet's size relative to its star, in exactly the same arithmetic used here for Venus and Mercury.",{"simplerExplanation":330},"Earth would dim a distant Sun-like star by about 0.0084%, small but bigger than what today's best space telescopes can detect — which is exactly how thousands of real exoplanets have been found.",{"id":332,"type":52,"variant":333,"title":334,"markdown":335},"e-misconception-see-planet","misconception","\"Astronomers actually see a picture of the planet\"","Almost never, for a transiting exoplanet. What is actually measured is a **graph of brightness over time** — a smooth line that dips by a tiny, precise, repeating percentage and then recovers. No picture of the planet itself is taken; its existence, size and orbital period are all worked out from the **shape and rhythm of the dip alone**, using exactly the geometry in this chapter. Only a small number of exoplanets, in special circumstances, have ever been directly photographed.",{"id":337,"type":156,"component":338,"componentVersion":5,"config":339,"objective":360,"textAlternative":361},"e-lab-match-worlds","match-pairs",{"prompt":340,"mode":341,"pairs":342},"Match each body or idea to the fact that goes with it.","connect",[343,345,348,351,354,357],{"a":96,"b":344},"Too small and too close-orbiting to ever cover the Sun — always a transit",{"a":346,"b":347},"Io","Comfortably wider than Jupiter's tiny, distant Sun — a true eclipse most orbits",{"a":349,"b":350},"Venus transit pair","Two transits eight years apart, then over a century's gap",{"a":352,"b":353},"Black drop effect","Smearing at Venus's edge that limited 18th-century timing precision",{"a":355,"b":356},"Transit dip","Proportional to the square of the crossing body's width, not its width alone",{"a":358,"b":359},"Exoplanet transit method","Finding planets around other stars from a tiny, repeating dip in starlight","Connect six ideas from across the Solar System — and beyond it — to the fact that defines each one.","A matching game pairing Phobos, Io, the Venus transit pair pattern, the black drop effect, the transit-dip-is-squared rule, and the exoplanet transit method with the single fact that best explains each.",{"id":363,"type":58,"title":364,"eyebrow":365,"navLabel":366},"e-ch6","Occultations: blocking a star instead of the Sun","Chapter 06","6 Occultations",{"id":368,"type":46,"markdown":369},"e-occult-intro","Widen the idea one more step. An eclipse or a transit is really just one example of a more general event: any time a nearer body passes in front of a more distant one and dims or hides it, astronomers call it an **occultation**. The Moon occults stars and planets often — you can watch a bright star vanish behind the Moon's dark edge on many nights, instantly, with no fading at all, because the Moon has no atmosphere to blur the edge.\n\nOccultations are not just pretty to watch. Timed carefully, from several locations, they have revealed things no direct picture could.",{"id":371,"type":52,"variant":80,"title":372,"markdown":373},"e-example-uranus-rings","Rings discovered by watching a star blink out early","In 1977, astronomers watched Uranus pass in front of a distant star, expecting a single clean dimming as Uranus itself blocked the starlight. Instead, the star blinked several times **before** Uranus even arrived, and again several times after it left. Each blink meant something narrow and dark had briefly blocked the star. That is how Uranus's rings were discovered — not by seeing them, but by timing a star vanishing and reappearing in a pattern no single planet could explain.",{"id":375,"type":52,"variant":80,"title":376,"markdown":377},"e-example-chariklo","The same trick finds a ring around a much smaller world","In 2013, a similar stellar occultation revealed rings around **Chariklo**, a small icy body orbiting between Saturn and Uranus — far too small and far too faint for any ring to be seen directly, even by the best telescopes of the time. A predicted occultation, watched from several observatories at once, again showed extra dips in starlight either side of the main event, revealing two narrow rings around a body barely 250 km across — proof that ring systems are not just a feature of giant planets.",{"id":379,"type":85,"caption":380,"columns":381,"rows":385},"e-table-family","The whole family, from narrowest to widest cover",[382,383,384],"Event","What crosses what","Typical cover",[386,390,394,398],[387,388,389],"Total eclipse","A body that looks bigger than the light source, from where you stand","Completely hides it",[391,392,393],"Annular \u002F partial eclipse or a big transit","A body of similar or smaller angular size","Partly hides it, or leaves a ring",[395,396,397],"Transit","A much smaller, usually distant body","A small dark dot, barely dimming the total light",[399,400,401],"Occultation","Any nearer body in front of any more distant one","The general case all the above belong to",{"id":403,"type":111,"prompt":404,"options":405,"explanation":414},"e-predict-occult-edge","A star occulted by the Moon vanishes almost instantly, with no fading at all. A star occulted by Mars (which has a thin atmosphere) fades slightly before disappearing completely. What does this difference tell you?",[406,408,410,412],{"id":115,"label":407},"Mars is bigger than the Moon",{"id":118,"label":409},"An atmosphere bends and scatters starlight gradually as the body's edge approaches, while an airless edge blocks it all at once",{"id":121,"label":411},"The Moon moves faster than Mars",{"id":124,"label":413},"Nothing — the difference is random","**(b).** A sharp, instant occultation is actually good evidence that the occulting body has **no atmosphere** — the star's light has nothing to bend or scatter through, so it is either fully visible or fully blocked, with nothing in between. A gradual fade, by contrast, is itself a way of detecting and even measuring the thickness of a thin atmosphere on a body too faint to study directly any other way — occultations have been used exactly this way to study the atmospheres of Pluto and Neptune's moon Triton.",{"id":416,"type":67,"title":417,"problem":418,"steps":419,"help":424},"e-we-occultation-timing","Why does watching from several places at once matter?","A single observer sees an occultation as a dimming that starts and ends at two moments in time. Explain why astronomers deliberately spread observers across many different locations for an important occultation, rather than relying on just one telescope.",[420,421,422,423],"A single timed dimming only tells you **when** the edge of the occulting body crossed that one observer's line of sight to the star — one chord across its shape, in effect.","An irregular body (an asteroid, a small moon, or a ring system) does not have the same width along every line of sight. One observer's timing cannot distinguish a big round shape from a small elongated one pointed the right way.","Multiple observers, spread across the predicted shadow path on Earth, each measure a different chord across the same event. Combine enough chords and you can reconstruct the occulting body's outline — its actual shape, not just a single width — the same way several straight cuts through an object reveal its cross-section.","This is exactly the same **geometry problem** as the path of a solar eclipse's shadow racing across Earth: a narrow track, only useful data if you are inside it, and far more informative if many observers along the track compare notes afterwards.",{"simplerExplanation":425},"One observer only measures one slice through the shadow's shape. Many observers spread out can piece together the whole outline, the way several straight cuts reveal a shape's silhouette.",{"id":427,"type":58,"title":428,"eyebrow":429,"navLabel":430},"e-ch7","Artificial eclipses: making your own corona, on demand","Chapter 07","7 Artificial eclipses",{"id":432,"type":46,"markdown":433},"e-artificial-intro","Discover explained why the corona is only visible during the few minutes of a natural total eclipse: the Sun's blinding disc normally drowns it out completely. For over a century, solar physicists have wanted a way around this — and two very different solutions now exist, one already flying, one very new.",{"id":435,"type":52,"variant":80,"title":436,"markdown":437},"e-example-coronagraph","The coronagraph: an artificial Moon, permanently in place","A **coronagraph** is an instrument with a small disc built into it, positioned to block out a star's or the Sun's bright disc inside the instrument itself — a tiny, permanent, artificial 'Moon' held exactly in the right place by careful optics. Space telescopes have carried Sun-watching coronagraphs for decades, giving a view of the corona every single day rather than for a few minutes every year or two. India's own **Aditya-L1** mission, launched in September 2023, carries a Visible Emission Line Coronagraph (VELC) for exactly this purpose, stationed at the **L1 Lagrange point** about 1.5 million km from Earth — roughly 1% of the way to the Sun, where the pull of Earth's and the Sun's gravity balance out and a spacecraft can sit with a permanently unobstructed view.",{"id":439,"type":52,"variant":80,"title":440,"markdown":441},"e-example-proba3","Two spacecraft, flying in formation, to fake a total eclipse","A newer idea, flown by the European Space Agency's **Proba-3** mission (launched on an ISRO PSLV rocket from India in December 2024), uses **two separate spacecraft** flying in extremely precise formation: one carries a disc that blocks the Sun, the other carries the camera, positioned exactly in the first spacecraft's shadow — recreating a real total eclipse's geometry artificially, for hours at a stretch during each orbit, rather than the few minutes nature allows. Formation-flying this precisely, with two independent spacecraft holding station to within a fraction of the width of a coin, was itself a major engineering achievement, before a single scientific image was even taken.",{"id":443,"type":444,"itemId":445,"prompt":446,"check":447,"hints":450,"feedback":453},"e-practice-l1","practice","eclipses.extend-p-l1","Aditya-L1 sits about 1,500,000 km from Earth. The average Earth-Sun distance is about 149,600,000 km. About what percentage of the way to the Sun is that? Round to the nearest whole per cent.",{"kind":448,"answer":5,"tolerance":5,"unit":449},"number","%",[451,452],"Divide the L1 distance by the Earth-Sun distance and multiply by 100.","1,500,000 ÷ 149,600,000 × 100 ≈ ?",{"correct":454,"incorrect":455},"Right: 1,500,000 ÷ 149,600,000 × 100 ≈ 1%, a small but crucial head start on watching the Sun.","1,500,000 ÷ 149,600,000 ≈ 0.01, or about 1%. Aditya-L1 is still overwhelmingly closer to Earth than to the Sun.",{"id":457,"type":156,"component":458,"componentVersion":5,"config":459,"objective":475,"textAlternative":476,"help":477},"e-lab-coronagraph","shadow-lab",{"objects":460,"source":469,"maxDistanceCm":470,"challenges":471},[461,465],{"id":462,"label":463,"heightCm":464},"small-disc","Small close disc",2,{"id":466,"label":467,"heightCm":468},"big-disc","Large distant disc",20,"point",400,[472],{"prompt":473,"targetRatio":474},"Match the small disc's shadow angle to the large disc's, by finding the right close distance.",0.1,"Show that a small disc held close can block the same angular size as a huge, distant one — the whole trick behind a coronagraph.","A lamp representing the Sun, a small disc you can slide close to a viewing point, and, further back, a much larger reference disc fixed at a great distance.\n\nSlide the small disc closer to the viewing point and watch its angular size grow, even though its real size never changes. At the right distance, the small disc's angular size exactly matches the large, distant disc's — demonstrating that a coronagraph's tiny built-in blocker can match the Sun's own apparent size purely through careful placement, with no need to be anywhere near the Sun's actual size.",{"hints":478},[479,480],"Angular size = real size ÷ distance. Halve the distance and the angular size doubles.","Compare this lab with the very first shadow lab in Discover — it is the same rule, used in reverse.",{"id":482,"type":111,"prompt":483,"options":484,"explanation":493},"e-predict-coronagraph","A coronagraph's built-in disc is much closer to the camera than the real Moon is to Earth. Given that angular size = real size ÷ distance, why can a small disc a short distance inside an instrument still block the Sun's much larger, much more distant disc?",[485,487,489,491],{"id":115,"label":486},"It cannot really — coronagraphs do not actually work",{"id":118,"label":488},"The disc's angular size, seen from the camera, can match the Sun's even though the disc itself is tiny, just by placing it close enough",{"id":121,"label":490},"Because the camera is more sensitive than a human eye",{"id":124,"label":492},"Because the disc is painted black","**(b).** The same rule used throughout this topic: what matters is **angular size**, real size divided by distance, not real size alone. A disc only a few centimetres across, mounted a short distance inside an instrument, can easily have the same angular size as the Sun's half-degree disc as seen from the camera behind it — exactly as a coin held near your eye can cover a distant mountain. The engineering challenge is not making the disc big; it is holding everything in exact, stable alignment, and stopping light diffracting around the disc's edge from swamping the faint corona anyway.",{"id":495,"type":58,"title":496,"eyebrow":497,"navLabel":498},"e-ch8","Puzzles to take further","Chapter 08","8 Puzzles",{"id":500,"type":67,"title":501,"problem":502,"steps":503,"help":508},"e-we-puzzle-phobos-grow","Puzzle: how much would Phobos have to grow?","Phobos's real angular size is only about 61.4% of the Sun's, as seen from Mars. If Phobos stayed at its real distance but grew until it exactly matched the Sun's angular size, how big would it need to be, and what percentage bigger is that than its real 22.5 km width?",[504,505,506,507],"If angular size must scale up by 1 ÷ 0.614 ≈ 1.629, then Phobos's diameter must scale up by the same factor (angular size is directly proportional to diameter, at a fixed distance).","New diameter ≈ 22.5 × 1.629 ≈ **36.7 km**.","Growth needed: (36.7 − 22.5) ÷ 22.5 × 100 ≈ **63%** bigger across.","**For comparison:** our own Moon does not need to grow at all to cause total eclipses — it already can, right at the edge of being big enough, which is the whole '400 and 400' coincidence from Discover. Phobos would need a much bigger boost, and it is shrinking towards Mars, not growing, so Mars is moving further from ever having a 'proper' total eclipse, not closer.",{"simplerExplanation":509},"Phobos would need to be about 63% wider than it really is — roughly 37 km instead of 22.5 km — to just cover the Sun from Mars.",{"id":511,"type":512,"tone":513,"items":514},"e-spec-puzzle-recap","spec","neutral",[515,519,523,527],{"label":516,"big":517,"value":518},"Phobos today","22.5 km wide","About 61% of the Sun's angular width from Mars — always a transit.",{"label":520,"big":521,"value":522},"Phobos, to fully cover the Sun","≈36.7 km wide","About 63% bigger, at the same altitude.",{"label":524,"big":525,"value":526},"Our Moon","3,475 km wide","Already just barely big enough, at perigee, for total eclipses.",{"label":346,"big":528,"value":529},"3,643 km wide","Nearly 5× the Sun's tiny angular width from Jupiter — always an eclipse.",{"id":531,"type":52,"variant":532,"title":533,"markdown":534},"e-question-open","question","Open questions for curious learners","Nobody has fully settled these. Pick one and dig in.\n\n- If you designed a fictional planet-moon system specifically to give the most spectacular possible total eclipses — long totality, wide path, frequent — what sizes and distances would you choose, and why can real systems rarely manage all three at once?\n- Saturn's rings cast a shadow on the planet itself. Is that an eclipse, by the definition used throughout this topic? Make the case either way.\n- If Earth had two moons instead of one, would total solar eclipses become more common, less common, or does it depend entirely on the second moon's size and orbit? Sketch out a few scenarios.\n- Exoplanet transits reveal a planet's size and orbit, but not directly its mass. What additional measurement, paired with a transit, could reveal the mass too — and hence the density and likely composition?\n- The 1919 eclipse tested gravity bending starlight. What is one prediction of modern physics that is genuinely hard to test today, the way relativity was hard to test before 1919 — and what special, rare event might one day make it possible?",{"id":536,"type":292,"prompt":537},"e-reflect-design","Using what you know about angular size (real size ÷ distance), sketch the numbers for a made-up moon that would give a planet **unusually long** totalities — longer than Earth's maximum of 7 minutes 32 seconds. Would you make the moon bigger, closer, slower-orbiting, or some combination? Explain your reasoning with at least one calculation.",{"id":539,"type":58,"title":540,"eyebrow":541,"navLabel":542},"e-ch9","Careers and citizen science built around eclipses","Chapter 09","9 Careers",{"id":544,"type":46,"markdown":545},"e-careers-intro","Eclipses are not only something to watch — for a surprising number of people, they are part of a working life or a serious hobby, and several of these paths are open to a curious student well before university.",{"id":547,"type":548,"title":549,"items":550},"e-steps-careers","steps","A few ways eclipses turn into work, research or a serious hobby",[551,555,559,563,567],{"title":552,"tag":553,"text":554},"Solar physicist","researcher","Studies the Sun's corona, magnetic field and eruptions, using coronagraphs, natural eclipses and spacecraft data such as Aditya-L1's.",{"title":556,"tag":557,"text":558},"Orbital mechanics engineer","engineer","Designs and predicts spacecraft trajectories precisely enough for missions like Proba-3's formation flying, or for computing eclipse paths centuries ahead.",{"title":560,"tag":561,"text":562},"Eclipse chaser \u002F astrophotographer","hobbyist to professional","Travels to totality paths worldwide, and some make a living leading tours, writing guides or selling photographs and footage.",{"title":564,"tag":565,"text":566},"Citizen scientist","volunteer","Ordinary observers time eclipse contacts, submit eclipse photographs to projects such as NASA's Eclipse Megamovie, or time occultations from their own backyard with modest equipment, contributing real data used by professional astronomers.",{"title":568,"tag":569,"text":570},"Science communicator \u002F planetarium educator","educator","Explains eclipse safety and science to the public before major events, often the difference between a town watching safely or not.",{"id":572,"type":52,"variant":247,"title":573,"markdown":574},"e-nuance-citizen","You do not need a telescope to contribute real data","Timing exactly when a star disappears and reappears during a lunar occultation, or exactly when totality begins and ends during a solar eclipse, needs only a clock, a clear view, and care — and these amateur timings, submitted to organisations that collect them, have genuinely refined orbital measurements and eclipse predictions. Some of the clearest historical examples of \"citizen science\" long predate the internet: 18th-century Venus transit timings (Chapter 4) were themselves contributed by observers scattered across the world, many of them not professional astronomers by modern standards at all.",{"id":576,"type":292,"prompt":577},"e-reflect-careers","Pick one career or citizen-science activity from the list above that interests you. Write two questions you would want to ask someone doing it, and one small step you could take this year — even something as simple as joining an eclipse-watching event or learning to use a stopwatch precisely — to find out more.",{"id":579,"type":58,"title":580,"eyebrow":581,"navLabel":582},"e-ch10","Wrap-up","Chapter 10","10 Wrap-up",{"id":584,"type":262,"items":585},"e-formulas-recap",[586,589,592,595],{"expression":587,"caption":588},"angle = size ÷ distance","Angular size, in radians (multiply by 57.3 for degrees) — the one rule behind every comparison in this layer.",{"expression":590,"caption":591},"dip % ≈ (width ratio)²","Light blocked in a transit, since brightness depends on area, not width.",{"expression":593,"caption":594},"L1 ≈ 1% of the Earth-Sun distance","Where Aditya-L1 sits, balancing Earth's and the Sun's gravity.",{"expression":272,"caption":596},"Venus's full transit-pair rhythm, added up.",{"id":598,"type":599,"conceptId":600,"relation":601,"explanation":602},"e-conn-gravity","connection","gravity","helps_understand","Every orbit in this layer — Phobos, Io, Venus, an exoplanet — is held in place by the same gravity studied in that topic.",{"id":604,"type":605,"title":606,"terms":607},"e-glossary","glossary","Words from beyond Earth",[608,611,615,617,620,624,628,631,635],{"term":395,"meaning":609,"example":610},"A smaller body crossing in front of a larger, more distant one, without covering it completely.","Mercury and Venus transit the Sun; Phobos transits it from Mars.",{"term":612,"meaning":613,"example":614},"Inferior conjunction","The moment an inner planet (Mercury or Venus) passes between Earth and the Sun.","A transit can only happen at inferior conjunction, near one of the planet's nodes.",{"term":352,"meaning":616},"An optical smearing of a transiting planet's silhouette against the Sun's edge, which limited historic timing precision.",{"term":618,"meaning":619},"Astronomical unit (AU)","The average Earth-Sun distance, about 149.6 million km, used as a convenient yardstick for the Solar System.",{"term":621,"meaning":622,"example":623},"Exoplanet","A planet orbiting a star other than the Sun.","Most known exoplanets were found by the transit method.",{"term":625,"meaning":626,"example":627},"Light curve","A graph of a star's brightness over time.","A transiting exoplanet shows up as a small, repeating dip in the light curve.",{"term":399,"meaning":629,"example":630},"A nearer body passing in front of a more distant one and hiding or dimming it — the general case an eclipse or transit belongs to.","The Moon occulting a star has a sharp edge, since it has no atmosphere to blur it.",{"term":632,"meaning":633,"example":634},"Coronagraph","An instrument with a small built-in disc that blocks a star's or the Sun's bright disc, revealing its faint surroundings.","India's Aditya-L1 carries a coronagraph to watch the Sun's corona every day.",{"term":636,"meaning":637,"example":638},"Lagrange point","A location in space where the gravity of two large bodies balances so a spacecraft can hold a stable position with little fuel.","L1, about 1% of the way from Earth to the Sun, gives an unobstructed view of the Sun.",{"id":640,"type":641,"title":642,"questions":643},"e-quiz","quiz","Check what you found beyond Earth",[644,657,670,683,696,709,722,735,748],{"itemId":645,"prompt":646,"options":647,"correct":118,"why":656},"eclipses.extend-q-phobos","Why can Phobos never cause a total eclipse on Mars?",[648,650,652,654],{"id":115,"label":649},"It is too far from Mars",{"id":118,"label":651},"Its angular size, about 0.215°, is smaller than the Sun's 0.350° from Mars",{"id":121,"label":653},"Mars has no atmosphere",{"id":124,"label":655},"Phobos does not orbit in the right plane, ever","Being smaller in the sky than the Sun means it can only ever transit, never fully cover it.",{"itemId":658,"prompt":659,"options":660,"correct":118,"why":669},"eclipses.extend-q-io","Why does Io cause true total eclipses on Jupiter, unlike Phobos on Mars?",[661,663,665,667],{"id":115,"label":662},"Io is closer to the Sun",{"id":118,"label":664},"Io's angular size, about 0.495°, is nearly five times the Sun's tiny 0.103° from Jupiter",{"id":121,"label":666},"Jupiter has no clouds",{"id":124,"label":668},"It does not; Io only transits too","Io looks far bigger than the distant, small-looking Sun from Jupiter, so its shadow is a true, sharp eclipse.",{"itemId":671,"prompt":672,"options":673,"correct":118,"why":682},"eclipses.extend-q-transit-dip","Venus's disc is about 3.03% of the Sun's width during a transit. Roughly what fraction of the Sun's light does it block?",[674,676,678,680],{"id":115,"label":675},"3.03%",{"id":118,"label":677},"About 0.09%",{"id":121,"label":679},"About 30%",{"id":124,"label":681},"None at all","Light blocked depends on area, so you square the width ratio: 0.0303² ≈ 0.00092, about 0.09%.",{"itemId":684,"prompt":685,"options":686,"correct":118,"why":695},"eclipses.extend-q-venus-pairs","Why do Venus transits come in pairs eight years apart, rather than evenly spaced?",[687,689,691,693],{"id":115,"label":688},"Venus's orbit changes shape every 8 years",{"id":118,"label":690},"After 8 years the alignment is still close enough to repeat once, then drifts too far for over a century",{"id":121,"label":692},"It is a coincidence with no explanation",{"id":124,"label":694},"Earth's orbit shifts by exactly 8 years' worth","The same kind of near-but-not-exact repeat seen in the Saros: good enough to repeat once at 8 years, not again until the cycle comes back around near 105 or 121 years later.",{"itemId":697,"prompt":698,"options":699,"correct":118,"why":708},"eclipses.extend-q-exoplanet","How do astronomers usually confirm and measure a transiting exoplanet?",[700,702,704,706],{"id":115,"label":701},"By photographing it directly, almost always",{"id":118,"label":703},"By measuring a small, precise, repeating dip in the host star's brightness over time",{"id":121,"label":705},"By listening for radio signals",{"id":124,"label":707},"By measuring the star's colour change","The light-curve dip, and its size and rhythm, are what reveal the planet — direct photographs are rare and difficult.",{"itemId":710,"prompt":711,"options":712,"correct":118,"why":721},"eclipses.extend-q-phobos-puzzle","About how much bigger than its real size would Phobos need to be, at its real distance, to exactly cover the Sun from Mars?",[713,715,717,719],{"id":115,"label":714},"About 10% bigger",{"id":118,"label":716},"About 63% bigger",{"id":121,"label":718},"About 400% bigger",{"id":124,"label":720},"It already covers the Sun","22.5 km would need to grow to about 36.7 km, roughly 63% larger, to match the Sun's angular size at Phobos's altitude.",{"itemId":723,"prompt":724,"options":725,"correct":118,"why":734},"eclipses.extend-q-occultation","Astronomers discovered Uranus's rings in 1977 by noticing what?",[726,728,730,732],{"id":115,"label":727},"A direct photograph of the rings",{"id":118,"label":729},"A star blinking several times before and after Uranus itself occulted it",{"id":121,"label":731},"A change in Uranus's colour",{"id":124,"label":733},"Radio signals from the rings","The extra dips either side of the main occultation revealed narrow, otherwise invisible rings.",{"itemId":736,"prompt":737,"options":738,"correct":118,"why":747},"eclipses.extend-q-coronagraph","How can a small disc inside a coronagraph block the Sun's much bigger, much more distant disc?",[739,741,743,745],{"id":115,"label":740},"It cannot; coronagraphs use filters instead",{"id":118,"label":742},"Its angular size, seen from the camera, can match the Sun's simply by placing it close enough",{"id":121,"label":744},"It uses a laser to cancel the sunlight",{"id":124,"label":746},"It only works during a real eclipse","Angular size depends on size divided by distance, so a small, close disc can have the same angular size as a huge, distant one.",{"itemId":749,"prompt":750,"options":751,"correct":118,"why":760},"eclipses.extend-q-jupiter-often","Why are eclipses effectively the 'default state' on Jupiter, unlike the delicate coincidence on Earth?",[752,754,756,758],{"id":115,"label":753},"Jupiter has no Sun visible at all",{"id":118,"label":755},"Every large Galilean moon is comfortably bigger, in the sky, than Jupiter's small, distant Sun, so no fine coincidence is needed",{"id":121,"label":757},"Jupiter's moons never move",{"id":124,"label":759},"It is not true; Jupiter has no eclipses","There is no near-miss to worry about — every big moon is safely oversized compared with the Sun as seen from Jupiter.",{"id":762,"type":763,"title":764,"points":765},"e-cheat","summary","Cheat sheet",[766,767,768,769,770,771,772,773,774,775,776],"**The same test works everywhere:** is the crossing body's angular size bigger or smaller than the Sun's, as seen from where you stand? Bigger → possible total eclipse. Smaller → transit only.","**Phobos (Mars):** only about 61% of the Sun's width — always a transit, however often it crosses. Deimos is even smaller, only about 10%.","**Io (Jupiter):** nearly 5 times the Sun's tiny, distant angular width — a true, sharp total eclipse most of its 42-hour orbits. Every large Galilean moon does the same.","**Mercury and Venus transit the Sun from Earth:** about 0.66% and 3.03% of its width. Light blocked depends on the **square** of that ratio — about 0.00004% and 0.09% respectively.","**Venus transit pairs:** 8 years apart, then a gap of 105.5 or 121.5 years — a 243-year full cycle. Last pair 2004\u002F2012; next pair 2117\u002F2125.","**Historic use:** 18th-century Venus transits, timed from many places on Earth (including Indian Ocean expeditions), gave the first solid estimate of the Earth-Sun distance, despite the smearing 'black drop effect'.","**Exoplanets are mostly found by the same trick:** a small, precise, repeating dip in a star's brightness, sized by the square of the planet-to-star width ratio — Earth would dim a distant Sun-like star by about 0.0084%.","**Occultations** are the general case: any nearer body passing in front of a more distant one. Timed from several locations, they revealed Uranus's rings (1977) and a ring around the small body Chariklo (2013), by catching extra dips either side of the main event.","**Artificial eclipses:** a coronagraph's small, close disc matches the Sun's angular size to block it — India's Aditya-L1 carries one at L1, about 1% of the way to the Sun. ESA's Proba-3, launched on an Indian rocket, flies two spacecraft in formation to fake an eclipse for hours at a time.","**Careers and citizen science:** solar physicists, orbital-mechanics engineers, eclipse chasers and amateur timers of occultations and transits all turn this topic into real, ongoing work — some of it open to a careful volunteer with just a clock and a clear sky.","**Puzzle takeaway:** our own Moon barely, but genuinely, covers the Sun — the '400 and 400' coincidence from Discover. Phobos would need to be about 63% bigger to do the same from Mars, and is shrinking towards Mars instead of growing.",{"id":778,"type":779,"sourceIds":780},"e-sources","sources",[781,782,783,784,785,786,787,788],"eclipses-nasa-eclipses","eclipses-nasa-planetary-facts","eclipses-wiki-solar","eclipses-wiki-transit-venus","eclipses-britannica-kids","eclipses-ncert-curiosity","eclipses-isro-aditya-l1","eclipses-esa-proba3",[781,782,783,784,785,786,787,788],"needs_review",{"generatedBy":792,"notes":793},"claude-code","Draft generated locally; pending owner review. Every number computed in scratchpad\u002Feclipses\u002Fnumbers.py and this generator's own header.","a6f2d61bcea37a560d97cd64f8f80ed97f7bddee48db183523cdebebf43eb00e",{"component:sort-game@1":796,"component:match-pairs@1":797,"logic:practice":798,"component:shadow-lab@1":799,"source:eclipses-britannica-kids":800,"source:eclipses-esa-proba3":801,"source:eclipses-isro-aditya-l1":802,"source:eclipses-nasa-eclipses":803,"source:eclipses-nasa-planetary-facts":804,"source:eclipses-ncert-curiosity":805,"source:eclipses-wiki-solar":806,"source:eclipses-wiki-transit-venus":807},"b164f45a2c8ca08f26c450768ff0231e113e9fe45381eddb34dc6d0548596c38","2a8ee4ac87460b4e1175a4bb13c96b03d577db06dde95670eb7fcfe4ad787899","3d6b0fe1b15255975a32b0fcd94e8019bc959ad45cbf12e136e86149549c6878","7476ef546fdb1f398a07393483e549c923f9568dc1bb1c2561191bf47862c475","b10d074ebe9d86c884d3f9aab5d21f1e9ba85495f2d6add6a9263b96a9eb0a6a","de7c84065e729200d3bb50a0b67407353ccb14686ec19d936226583f07fb90d0","8e8d05d02b7eba3e084b1464c4c56bd3c6c56c5bd90507b4164d3d5434a02bde","c0bbcfd69fe06099e49c296bba2b105973ec1a794b69292fb65b4d81e9a2d672","2722ed5e392e0daa2619f1f854869d4ed7201f3bb3fbf378bf0342f999f2ab1c","c8e27588447f45548af86f4ac4ceb632dd451d78252b13c94d725b85ce34a24d","e32e7e8bfd7f8db32db243544cfc60cb96c0c7f050e964450ae3fc99bb21d344","10f244ed7daf75bfbcb39f6bb6c3b1a81662195ba570ae6297b62ff8cd4279e1",{"state":809,"reviewer":810,"selfReview":811,"reviewedAt":812,"method":813},"approved","The library owner",true,"2026-09-20T10:18:37.581Z","owner_bulk","preview-7e1cbbcc4f",1789899597996]