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CuriosityCh 12 Earth se Aage

Beyond Earth (Earth se Aage): Class 6 Science Chapter 12 Hinglish mein

Curiosity · Hinglish notes, simulations aur practice · Official NCERT chapter PDF ↗

Published · Updated

  • 105 min
  • 3 simulations
  • 17 practice questions
  • 35 MCQs

Is chapter mein aap kya seekhenge

  • Samjhana ki stars door ke suraj hain jo apni roshni khud banate hain, aur log unhe constellations mein group kyun karte hain
  • Big Dipper se Pole Star aur north dhoondhna, aur Orion's belt se Sirius dhoondhna
  • Light pollution ko samjhana aur kisi bade ke saath ek safe night-sky watch plan karna
  • Solar System ke members ke naam batana aur aath planets ko Sun se unke order mein likhna
  • Rocky inner planets ko giant outer planets se compare karna, aur aasmaan mein planet aur star ka farq pehchanna
  • Moon, asteroids aur comets ke baare mein batana, aur samjhana ki Sun ke paas comet ki tail kyun ban jaati hai
  • Earth aur Solar System ki jagah Milky Way Galaxy aur Universe ke andar samajhna

NCERT Science Class 6, Chapter 12, pp. 231–254 par based original companion text. Yeh NCERT se juda nahi hai aur NCERT ne ise endorse nahi kiya hai.

Upar dekho

Socho, saaf aasmaan wali ek raat hai, chaand nahi hai, aur light chali gayi. Pankhe ruk jaate hain, streetlights bujh jaati hain, aur tum chhat par chadh jaate ho. Dheere-dheere aasmaan roshni ke chhote-chhote points se bhar jaata hai: pehle kuch chamakdaar, phir darjanon, phir itne ki gin hi na sako.

Mann mein sawaal aane lagte hain. Yeh roshniyan kitni door hain? Kuch zyada chamakdaar kyun hain? Kya yeh chalti hain? Hazaaron saalon se log yahi sawaal poochhte aaye hain. Oonton par safar karne wale aur andhere samudr par chalne wale sailors to stars ki madad se raasta bhi dhoondhte the.

Is chapter mein hum step by step bahar ki taraf safar karenge. Shuru karenge chhat se dikhne wale stars se. Phir Sun aur uske planets ki family se milenge. Aakhir mein bahut door, apni galaxy aur poore Universe tak jaayenge.

3/3Koi aur kuch wahi stars use karta hai aur use ek machhli dikhti hai.

Fig. 12.1Wahi stars bilkul alag pictures bana sakte hain. Lines sirf hamari imagination mein hoti hain.NCERT Activity 12.1 · p. 232

Halke aasmaan ka ek panel jismein alag-alag size ke lagbhag pachchees stars bikhre hain. Pehle step mein sirf stars hain aur sawaal hai: tumhe kya dikha?. Doosre step mein saat stars orange lines se jud kar patang ki shape banate hain: ek diamond, do cross karti dandiyan aur neeche latakti zigzag tail; label hai patang. Teesre step mein patang ki lines hat jaati hain aur kuch wahi stars, kuch naye stars ke saath, dashed purple lines se jud kar right ki taraf mooh wali machhli banate hain; left mein triangle wali tail hai aur ek star uski aankh hai; label hai machli.

InteractiveSky sketchpad

Ek interactive star chart jismein chunne ke liye teen skies hain: apna pattern banane ke liye stars ka ek banaya hua patch, Big Dipper, Little Dipper aur Pole Star wala northern sky, aur Orion aur Sirius wala sardiyon ki shaam ka sky. Ek star aur phir doosre par tap karne se unke beech line ban jaati hai. Buttons se tum aakhri line undo kar sakte ho, saari lines clear kar sakte ho, aur dono asli skies mein answer ko labels ke saath dashed lines mein dekh sakte ho.

Fig. 12.2Ek star par tap karo, phir doosre par, unhe jodne ke liye. Activity 12.1 ke liye Your own pattern use karo, aur baaki do skies chapter mein aage aane wale star hunts ke liye.
Quick check
2 mein se 1
Kaafi strong telescope ho to tum pattern ke stars ko jodne wali lines dekh sakte ho.
Answer dekho

Answer Galat

Aasmaan mein koi lines nahi hain. Log stars ke groups ko pictures banane ke liye unhe imagine karte hain, isliye alag-alag cultures ne alag-alag pictures banayi.

12.1 Stars aur Constellations

Chhat se dikhne wale aasmaan ka lagbhag har roshni ka point ek star (तारा) hai. Star bahut garam gas ka ek bahut bada gola hai jo chamakta hai. Woh apni roshni aur heat khud banata hai, bilkul hamare Sun ki tarah. Sach to yeh hai ki Sun bhi ek star hai, bas bahut paas wala.

Kuch stars chamakdaar dikhte hain aur kuch dhundhle. Koi star isliye chamakdaar dikh sakta hai kyunki woh sach mein bahut roshni deta hai, ya bas isliye kyunki woh humse zyada paas hai. Ek dhundhla star bahut bada ho sakta hai, par bahut hi door.

Definition
Star

Bahut garam, chamakti gas ka ek bahut bada gola jo apni roshni aur heat khud banata hai.

ExampleSun, Sirius aur Pole Star, sab stars hain.

Hamare purvajon ke paas na screens thi, na electric lights, par har saaf raat unke paas andhera aasmaan tha. Unhone stars ke aise groups dekhe jo saath-saath lagte the. Apne mann mein unhone stars ke beech shikaari, jaanwar, hal aur naavein banayi, aur unke saath kahaaniyan bhi banayi. Har culture ke apne pictures the aur unke apne naam.

Yeh star pictures sirf sone se pehle ki kahaaniyan nahi thi. Jo pattern tum achhi tarah jaante ho, use dobara dhoondhna aasaan hota hai. Isse bhi badhiya baat, har pattern saal dar saal unhi jagahon par ugta aur doobta hai. To woh aasmaan par bane map ki tarah kaam karte the. Compass ya phone ke GPS se bahut pehle, sailors aur registaan ke vyapari inhi ke sahaare raasta chalte the. Aaj bhi raat mein raasta bhatka insaan inse direction pata kar sakta hai.

Astronomers constellation (तारामंडल) word ko do tarah use karte hain. Officially, ab constellation aasmaan ka ek ghera hua patch hai, jiska naam uske andar ke star pattern par rakha gaya hai. Roz ki baatcheet mein log yeh word khud star pattern ke liye use karte hain, jaise Orion, the hunter (shikaari).

Definition
Constellation

Stars ka ek group jo pattern banata lagta hai, ya aasmaan ka woh marked area jismein aisa pattern hota hai.

ExampleOrion, the hunter (shikaari), ek constellation hai.

Chalo, kuch famous constellations se milte hain. Orion ko ek shikaari ki tarah dikhaya jaata hai. Iska sabse aasaan dikhne wala hissa shikaari ki belt hai: teen chamakdaar stars jo paas-paas ek chhoti seedhi line mein hain. Ek laal-sa star, Betelgeuse, ek kandha hai, aur ek neela-safed star, Rigel, ek ghutna hai.

Orion ke paas Canis Major hai, shikaari ka bada kutta. Ismein Sirius hai, jo raat ke har doosre star se zyada chamakta hai. Orion ki doosri taraf Taurus hai, yaani bail. Aldebaran naam ka ek orange star uski aankh hai, aur Pleiades naam ka stars ka ek chhota, dhundhla-sa cluster uske kandhe par hai. Fig. 12.3 mein dekho ki belt kaise signpost ki tarah kaam karti hai.

4/5Belt ko doosri taraf follow karo: yeh Taurus ke orange Aldebaran tak aur phir chhote Pleiades cluster tak le jaati hai.

Fig. 12.3Orion's belt ek signpost hai: ek taraf follow karo to Sirius milta hai, doosri taraf Taurus. Stars ki jagah asli hai; lines imagine ki gayi hain.NCERT Fig. 12.3 · p. 234

Halke aasmaan ke panel par ek star chart. Step one Orion par zoom karta hai: ek chhoti seedhi line mein teen stars ke chaaron taraf circle hai aur label hai belt. Step two Orion ke stars ko orange lines se jod kar shikaari ki shape banata hai; upar laal-se star par Betelgeuse aur neeche neele star par Rigel likha hai. Step three zoom out karta hai, to Orion chhota dikhta hai; ek dashed arrow belt se neeche-left ki taraf bahut chamakdaar star Sirius tak jaata hai, aur Canis Major ke stars jud kar kutte ki shape banate hain. Step four belt se upar-right ki taraf ek doosra dashed arrow jodta hai jo Taurus ke V-shaped chehre mein orange star Aldebaran tak jaata hai, aur uske aage chhota Pleiades cluster hai. Step five English naamon ki jagah Indian naam dikhata hai: Betelgeuse ke liye Ardra, Aldebaran ke liye Rohini, Pleiades ke liye Krittika aur Sirius ke liye Lubdhaka.

Ab northern sky ki taraf mudo. Wahan saat chamakdaar stars ek badi kalchhi ya mude handle wale saucepan jaisi shape banate hain. Yeh hai Big Dipper. Paas hi ek chhoti, dhundhli kalchhi hai, Little Dipper.

Little Dipper ke handle ke sire wala star Pole Star (ध्रुव तारा) hai, jise Polaris bhi kehte hain. Raat bhar baaki stars dheere-dheere aasmaan mein ghoomte hain. Lekin Pole Star lagbhag ek hi jagah, north ke upar, tika rehta hai. To agar tum use dhoondh lo, to tumhe pata chal jaayega ki north kis taraf hai. Yeh sirf Earth ke northern half mein kaam karta hai, jismein India bhi hai.

Trick yeh hai. Big Dipper ke bowl ki bahar wali side banane wale do stars dhoondho. Yeh pointer stars hain. Aankh se unke beech ka gap andaaza lagao. Phir usi line par bowl ki khuli side se aage badho. Ek gap, do gap, aise ginte hue lagbhag paanch gap tak jao. Tum ek akele, medium-chamakdaar star par pahunchoge. Wahi Pole Star hai. Yeh trick, aur aasmaan ka dheere-dheere ghoomna, Fig. 12.4 mein dekho.

4/5Pole Star Little Dipper ke handle ke sire par hai.

Fig. 12.4Pointer stars se Pole Star dhoondho. Jaise-jaise raat aage badhti hai, aasmaan uske chaaron taraf ghoomta hai.NCERT Fig. 12.4 · p. 235

Halke panel par northern sky ka chart, jis par north dekho likha hai. Step one mein sirf bikhre hue stars hain. Step two aasmaan mein oonche saat stars ko jod kar Big Dipper banata hai: chaar stars ka bowl aur teen stars ka handle. Step three bowl ke bahar wale kinare ke do stars ko circle karta hai, label hai pointer stars, aur unse neeche-left ke ek star tak dashed line kheenchta hai, jiska label hai Pole Star; raaste mein chhote dots lagbhag paanch barabar gaps dikhate hain. Step four Little Dipper jodta hai, jiska handle Pole Star par khatam hota hai. Step five do ghante baad ka aasmaan dikhata hai: Big Dipper aur Little Dipper Pole Star ke chaaron taraf circle ka barahvaan hissa anticlockwise ghoom gaye hain, ek curved arrow ghoomne ki direction dikhata hai, ek dashed outline dikhati hai ki Big Dipper pehle kahan tha, aur Pole Star nahi hila.

Quick check
4 mein se 1
Constellations ke baare mein kaunsi baat sahi hai?
Answer dekho

Answer (C) Yeh aasmaan ke patterns ya regions hain jo stars pehchanne mein hamari madad karte hain

Constellations woh patterns hain jo log imagine karte hain, aur aaj aasmaan ke 88 official regions bhi. Aasmaan mein koi asli lines nahi hain, aur raat mein saare constellations aasmaan mein chalte hain.

12.2 Raat ka Aasmaan Dekhna

Kisi gaon ya jungle camp mein saaf raat ko tum hazaar ya usse bhi zyada stars dekh sakte ho. Bade shehar ke beech se shayad sirf mutthi bhar gin pao. Stars kahin nahi gaye. Koi cheez unhe chhupa rahi hai.

Stars hamari apni lights ki wajah se chhup jaate hain. Streetlights, chamakte hoardings, floodlights wali buildings aur headlights, sab kuch roshni upar ki taraf bhi phenkte hain. Dhool aur dhuen ke chhote kan, aur khud hawa, usmein se kuch roshni wapas neeche bikher dete hain. Phir poora aasmaan halka orange ya grey chamakne lagta hai. Is chamak ke saamne dhundhle stars bas gaayab ho jaate hain. Raat mein bahut zyada artificial light ko light pollution (प्रकाश प्रदूषण) kehte hain.

Definition
Light pollution

Raat mein bahut zyada artificial light, jo aasmaan ko chamkila bana deti hai aur dhundhle stars ko chhupa deti hai.

ExampleShehar ka aasmaan jo aadhi raat ko orange chamakta hai.

2/3Khule lamps upar ki taraf bhi chamakte hain. Aasmaan chamakne lagta hai aur dhundhle stars gaayab ho jaate hain.

Fig. 12.5Upar ki taraf bikharti roshni aasmaan ko chamka deti hai. Dhake hue lamps zameen ko roshan karte hain aur stars dikhte rehte hain.

Teen gharon, do lamp posts aur taaron bhare aasmaan wala ek gaon. Step one mein lamps off hain, khidkiyan andheri hain aur aasmaan chamakdaar aur dhundhle stars se bhara hai. Step two mein lamps khule bulbs hain jo har direction mein chamakte hain, kirnein upar ja rahi hain, khidkiyan roshan hain, horizon se ek garam chamak uthti hai jiska label hai sky glow, aur zyaadatar dhundhle stars gaayab ho gaye hain, bas kuch chamakdaar bache hain. Label par likha hai roshni upar. Step three mein lamps ke upar dhakkan hain, unki roshni do cones mein neeche zameen par girti hai, sky glow bahut kam hai aur dhundhle stars wapas aa gaye hain. Label par likha hai dhake lamps.

Maan lo January ki ek shaam tum Orion aasaani se dhoondh lete ho. July ki shaam use dhoondho, to woh kahin nahi dikhega. Saal ke us samay woh sirf din mein upar hota hai. Fig. 12.6 dikhata hai kyun. Saal bhar dikhne wale stars badalte rehte hain. Tum kahan rehte ho, yeh bhi matter karta hai. Australia mein, equator ke south mein rehne wala dost Pole Star kabhi dekh hi nahi paata, kyunki wahan woh horizon ke neeche rehta hai.

2/2Chhah mahine baad Earth, Sun ki doosri taraf hoti hai. Ab Orion usi direction mein hai jismein Sun, isliye woh sirf din mein upar hota hai. Aadhi raat ko tumhare saamne iski jagah Scorpius hota hai.

Fig. 12.6Jab Earth Sun ke chaaron taraf ghoomti hai, to uski raat wali side alag-alag stars ki taraf hoti hai, isliye raat ka aasmaan saal bhar badalta rehta hai.NCERT p. 236

Upar se dekha gaya view, scale ke hisaab se nahi, jismein beech mein Sun hai aur uske chaaron taraf Earth ka raasta ek dashed circle hai. Star pattern Orion left mein bahut door hai aur star pattern Scorpius right mein bahut door. Step one mein January hai: Earth, Sun ke left mein, Sun aur Orion ke beech hai, aur Earth ki raat wali side se ek arrow Sun se ulti taraf seedha Orion ki taraf jaata hai, label hai January aadhi raat: Orion saamne. Step two mein Earth aadha chakkar ghoom kar Sun ke right mein aa gayi hai. Ab uska aadhi raat wala arrow Scorpius ki taraf hai, jabki Earth se ek dotted line Sun se hokar halke Orion tak jaati hai, label hai July: Orion, Sun ke peeche.

To star hunt se pehle do cheezein check karo: tum kaunsi shape dhoondh rahe ho, aur kab aur kis direction mein dekhna hai. Fig. 12.3 aur Fig. 12.4 ke star charts tumhe shapes sikhate hain. Kab aur kahan ke liye Stellarium aur Sky Map jaise free sky-map apps madad karte hain. Apna phone aasmaan ki taraf karo, aur woh dikha dete hain ki wahan kaunse stars aur planets hain.

Step by step

Apni night-sky watch khud plan karo

Step 1 / 6

Kisi bade ke saath jagah chuno

Kisi bade ke saath milkar ek andheri, khuli jagah chuno, jaise chhat, khet ya gaon ka maidaan. Streetlights, oonchi buildings aur ped beech mein nahi aane chahiye.

1 / 6
Quick check
4 mein se 1
Bade shehar mein aam taur par gaon se kam stars kyun dikhte hain?
Answer dekho

Answer (C) Chamakti lights, dhuan aur dhool dhundhle stars ko chhupa dete hain

Har jagah ke upar wahi stars hain, utni hi door. Shehar mein light pollution, dhuan aur dhool aasmaan ko chamka dete hain, aur dhundhle stars us chamak mein kho jaate hain.

12.3 Hamara Solar System

Chhat wale aasmaan ko phir se dekho. Wahan ki kuch sabse chamakdaar roshniyan star hain hi nahi. Aur hamari zindagi ka sabse zaroori star itna paas hai ki woh raat ko din bana deta hai. Chalo, space mein apne hi mohalle ko explore karte hain.

Sun

Tumhare sabse paas kaunsa star hai? Wahi jo tum roz subah dekhte ho! Sun hamara sabse nazdeek ka star hai, chamakti gases ka ek bahut bada gola jo Earth ki kisi bhi bhatti se zyada garam hai. Uske andar gehraai mein energy hamesha banti rehti hai aur roshni aur heat ban kar bahar nikalti hai.

Apna pichhla khaana, pichhli baarish aur dopahar mein apni skin par lagti garmi ke baare mein socho. Yeh sab Sun par depend karte hain:

  • Jo roti, chawal ya dal tum khaate ho, woh dhoop mein uge paudhon se shuru hui. Jaanwar, hum bhi, apna khaana paudhon se paate hain, aur paudhe woh oxygen bhi dete hain jo hum saans mein lete hain.
  • Dhoop samudr aur jheelon ko garam karti hai, aur unse paani water vapour ban kar upar uthta hai. Isi se water cycle chalta rehta hai aur monsoon ki baarish aati hai.
  • Zameen, paani aur hawa alag-alag had tak garam hote hain, aur isse hawaayein chalti hain. Isi se hamara weather aur hamare mausam bante hain.
  • Sun ki garmi ke bina Earth poori jam jaati, aur yahan kuch bhi zinda nahi reh paata.

Kai Indian tyohaar Sun ko dhanyavaad dete hain, jaise Makar Sankranti, Pongal aur Chhath. Purane samay se India mein log Sun ko Surya ke roop mein poojte aaye hain, aur kai doosre deshon ke log bhi Sun devta ki pooja karte the.

Sun humse lagbhag 150 million km door hai. Yaani 15 crore km! Space mein doori itni badi hoti hai ki astronomers Solar System ke liye ek bada unit use karte hain. Earth se Sun tak ki doori ko ek astronomical unit kehte hain, aur ise au likhte hain.

Definition
Astronomical unit (au)

Earth aur Sun ke beech ki average doori, lagbhag 150 million km. Ise Solar System ke andar ki dooriyan naapne ke liye use karte hain.

ExampleJupiter, Sun se lagbhag 5 au door hai.

Example

Car se Sun tak ka safar

Maan lo ek car space mein lagaataar 100 km/h ki speed se chal sakti, bina aaraam ya petrol ke liye ruke. 150 million km (15 crore km) door Sun tak pahunchne mein use kitna time lagega?

Pehle khud try karo. Phir solution ek-ek step karke kholo.

Sun bahut bada bhi hai. Woh Earth se lagbhag 109 guna chauda hai, aur uske andar lagbhag 13 lakh Earths sama sakti hain. Phir bhi aasmaan mein woh door pakdi ek plate se bada nahi dikhta. Aisa isliye kyunki woh bahut door hai.

Ab tum stars ki ek paheli hal kar sakte ho. Ek bade maidaan ke us paar ek street lamp ke baare mein socho: paas se woh aankhein chaundhiya deta hai, door se ek chhota sa dot lagta hai. Har star bhi ek suraj hai, aur kai to hamare Sun se kahin bade hain. Woh dots jaise sirf isliye dikhte hain kyunki woh hamare Sun se bahut zyada door hain. Din mein dhoop poore aasmaan ko chamka deti hai, isliye unki dhundhli roshni nahi dikhti, halaanki woh wahin upar hote hain. Dono ideas dekhne ke liye Fig. 12.7 ke steps dekho.

2/3Hamara Sun paas hai, isliye bada dikhta hai. Baaki suraj itne door hain ki dots jaise dikhte hain.

Fig. 12.7Koi cheez jitni door hoti hai, utni chhoti dikhti hai. Stars bahut door se dikhte suraj hain.

Teen scenes. Step one mein ek sadak door tak jaati hai aur uske kinare chaar ek jaise street lamps hain; sabse paas wala lamp bada dikhta hai aur uska label near hai, jabki sabse door wala ek chhota dot lagta hai aur uska label far hai. Step two mein left mein ek bada chamakta Sun hai, label our Sun, aur ek dashed line uski chhoti se chhoti copies tak jaati hai, label baaki stars, suraj, bahut door. Step three mein din ka chamakdaar aasmaan hai, left mein kirnon wala Sun hai, label tez dhoop, aur right mein kai dashed star outlines bikhri hain, label stars wahin hain.

ExampleNCERT Aur jaano · p. 240

Aasmaan ko chhota karo

Sun ke baad sabse paas ka star Proxima Centauri hai, lagbhag 2,69,000 au door. Ek model socho jismein 1 au, yaani Earth se Sun tak ki poori doori, sirf 1 cm ki ho jaati hai, lagbhag tumhare nakhoon jitni chaudi. Is model mein Proxima Centauri kitni door hoga?

Pehle khud try karo. Phir solution ek-ek step karke kholo.

SimulationGhoomti Earth par din aur raat

Upar se dekha gaya Sun aur Earth ka ek model. Earth apne axis par ghoomti hai, isliye uski har jagah dhoop wale half se andhere half mein jaati hai aur wapas aati hai, jabki Earth dheere-dheere Sun ke chaaron taraf apne raaste par aage badhti hai.

Fig. 12.8Earth ghoomti rehti hai aur saath hi dheere-dheere Sun ke chaaron taraf chalti hai.
Try karo
  • India wale dot ko dekho. Lagbhag kitne baje (IST) woh andhere half se roshni wale half mein jaata hai?
  • Earth ka kaunsa half roshan hai? Us half ke hisaab se Sun kahan hai?
  • Jab Earth Sun ke chaaron taraf apne raaste par bas thoda sa aage badhti hai, tab tak kitne din beet jaate hain?
Quick check
4 mein se 1
Sun baaki stars se itna bada aur chamakdaar kyun dikhta hai?
Answer dekho

Answer (B) Woh kisi bhi doosre star se humse bahut zyada paas hai

Sun ek aam star hai jo bas bahut paas hai. Kai stars usse bade aur zyada chamakdaar hain, par woh bahut zyada door hain. Saare stars apni roshni khud banate hain.

Planets

Hamari Earth ek planet (ग्रह) hai: ek bada, gol body jo lagaataar Sun ke chaaron taraf ghoomta rehta hai. Planet apni roshni khud nahi banata. Woh sirf isliye chamakta hai kyunki us par dhoop padti hai aur takra kar laut jaati hai.

Definition
Planet

Ek bada, gol body jo apne raaste par Sun ke chaaron taraf ghoomta hai aur apni roshni khud nahi banata.

ExampleEarth, Mars aur Jupiter planets hain.

Kisi body ke doosri body ke chaaron taraf ek poore chakkar ko revolution (परिक्रमण) kehte hain. Earth lagbhag ek saal mein Sun ke chaaron taraf ek revolution poora karti hai. Saat aur planets bhi Sun ke chaaron taraf revolve karte hain, har ek apne raaste par aur apni speed se. Mercury ko ek chakkar ke liye sirf 88 din chahiye. Door ke Neptune ko lagbhag 165 saal lagte hain!

Definition
Revolution

Kisi body ka apne raaste par doosri body ke chaaron taraf ek poora chakkar.

ExampleEarth lagbhag 365 din mein Sun ke chaaron taraf ek revolution karti hai.

Sun, planets aur Sun ke chaaron taraf ghoomne wali baaki saari bodies milkar Solar System (सौर मंडल) banate hain. Fig. 12.9 mein planets ko chalte dekho.

SimulationChalte hue planets

Upar se dekha gaya Solar System ka ek model, beech mein Sun aur uske chaaron taraf apne raaston par chalte aath planets. Inner planets tezi se ghoomte hain aur outer planets dheere. Ek switch drawing ko paas-paas dabaayi gayi dooriyon se asli dooriyon mein badal deta hai.

Fig. 12.9Har planet apni speed se Sun ke chaaron taraf revolve karta hai. Asli dooriyan mehsoos karne ke liye true scale par switch karo.
Try karo
  • Jab tak Earth Sun ka ek chakkar lagati hai, gino ki Mercury kitne chakkar lagata hai.
  • Neptune par tap karo. Sun ka ek chakkar lagane mein use kitne Earth years chahiye?
  • True scale par switch karo. Chaar rocky planets ka kya hota hai, aur ab har planet bas ek dot kyun hai?

Sun se bahar ki taraf jaate hue pehle Mercury, Venus, Earth aur Mars aate hain. Phir ek bade gap ke baad Jupiter, Saturn, Uranus aur Neptune aate hain. Order yaad rakhne mein ek mazedaar sentence madad kar sakta hai: My Very Eager Mother Just Served Us Noodles. Kya tum apna khud ka ek bana sakte ho, shayad apni bhasha mein?

2/4Sun ke sabse paas ke chaar planets chhote aur rocky hain. Mars ke aage asteroid belt hai.

Fig. 12.10Aath planets order mein. Sizes sirf aakhri step mein scale ke hisaab se hain; yahan dooriyan kabhi scale ke hisaab se nahi hain.NCERT Fig. 12.7 · p. 241

Sun ka kinara left side bhar deta hai. Uske right mein aath planets naam ke labels ke saath ek line mein hain: Mercury, Venus, Earth, Mars, asteroid belt ke liye bikhre dots, phir dhaariyon wala Jupiter, ring wala Saturn, Uranus aur Neptune. Step two mein rocky planets label wala ek bracket pehle chaar ko gherta hai, giants halke ho jaate hain, aur asteroid belt par label lagta hai. Step three mein giant planets label wala bracket aakhri chaar ko gherta hai aur rocky planets halke ho jaate hain. Step four mein har planet doosron ke mukable apne asli size mein bada ya chhota ho jaata hai: chaar rocky planets chhote dots ban jaate hain, Jupiter aur Saturn bahut bade ho jaate hain, aur Sun ka kinara lagbhag seedhi deewar ban jaata hai kyunki woh un sabse bahut bada hai.

Table 12.4Sun ke aath planets
PlanetIndian naamKis tarah kaAise yaad rakho
MercuryBudhrockysabse chhota planet, Sun ke sabse paas
VenusShukrarockyhamare aasmaan ka sabse chamakdaar planet, aur sabse garam bhi
EarthPrithvirockyBlue Planet, life ka akela jaana-maana ghar
MarsMangalrockyRed Planet, do chhote moons ke saath
JupiterBrihaspati ya Gurugiantsabse bada planet, ek giant toofan ke saath
SaturnShanigiantsabse chaude, sabse chamakdaar rings
UranusArungiantkarvat lete hue ghoomta hai
NeptuneVarungiantSun se sabse door, tez aandhiyon wala
Compare

Do tarah ke planets

Inner (rocky) planets

  • Mercury, Venus, Earth aur Mars
  • Chhote
  • Thos, pathreeli surface jis par khade ho sakte ho
  • Kam moons ya ek bhi nahi
  • Koi rings nahi

Outer (giant) planets

  • Jupiter, Saturn, Uranus aur Neptune
  • Bahut bade: Jupiter, Earth se lagbhag 11 guna chauda hai
  • Zyaadatar gas aur ice, khade hone ke liye koi thos zameen nahi
  • Har ek ke kai moons
  • Dhool, patthar aur ice ke rings

Teen planets ke nicknames hain. Space se dekhne par Earth zyaadatar neeli dikhti hai, kyunki uske lagbhag saat-das hisse par samudr hain. Isliye use Blue Planet kehte hain. Mars orange-laal dikhta hai, kyunki uski zameen par zang lagi, iron se bhari dhool hai. Isliye woh Red Planet hai.

Venus aksar suraj doobne ke baad west mein neeche dikhne wali pehli chamakdaar roshni hota hai. Saal ke doosre samay woh suraj ugne se pehle east mein neeche sabse aakhir mein fika padta hai. Isliye log use Evening Star ya Morning Star kehte hain. Yeh naam galat samjhaate hain: Venus ek planet hai, aur woh sirf dhoop ko reflect karta hai.

Saturn apne chamakdaar, chaude rings ke liye famous hai. Jupiter, Uranus aur Neptune ke bhi rings hain, par unke patle aur dark hain. Yeh saare rings ice, dhool aur patthar ke anginat tukdon se bane hain jo planet ke chaaron taraf ghoomte hain.

Kya tumhe lagta hai ki Sun ke sabse paas wala planet Mercury sabse garam hoga? Aisa nahi hai. Sun ke paas hone se planet garam zaroor hota hai. Par planet ki hawa ki chaadar, yaani uska atmosphere, bhi matter karta hai. Venus bahut ghani hawa mein lipta hai jo heat ko rok leti hai. Mercury par lagbhag koi hawa nahi hai, isliye uski heat nikal jaati hai. Isi wajah se Venus, Mercury se bhi zyada garam hai. Fig. 12.11 mein dono ko compare karo.

3/3Venus ki ghani hawa heat ko rok leti hai, aur use hamesha lagbhag 465 °C par rakhti hai.

Fig. 12.11Sun se doori matter karti hai, par planet ki hawa bhi.NCERT p. 242

Sun ka kinara left mein hai, aur dhoop ke dashed arrows paas wale grey Mercury aur door wale halke peele Venus tak pahunchte hain. Step one mein unke labels hain Sun ke zyada paas aur lagbhag dugna door. Step two mein Mercury ke chaaron taraf chhote arrows bahar ki taraf hain, label heat nikalti, aur temperatures hain din: 430 degree Celsius aur raat: minus 180 degree Celsius. Step three mein Venus ke chaaron taraf hawa ki ek moti dotted layer hai, label thick air, chhote arrows wapas planet ki taraf mudte hain, label heat rukti hai, aur temperature din-raat 465 degree Celsius hai.

Quick check
4 mein se 1
Inmein se kaun apni roshni khud banata hai?
Answer dekho

Answer (C) Sirius

Sirius ek star hai, isliye woh apni roshni khud banata hai. Venus aur Moon sirf isliye chamakdaar dikhte hain kyunki woh dhoop ko reflect karte hain. Venus ko Morning Star kehte hain, par woh ek planet hai.

Aasmaan mein planets dhoondhna

Kya hum planets ko waise hi dhoondh sakte hain jaise star patterns? Haan. Paanch planets sirf aankhon se dekhe ja sakte hain: Mercury, Venus, Mars, Jupiter aur Saturn. Venus sabse aasaan hai, kyunki raat ke aasmaan mein sirf Moon usse zyada chamakta hai.

Par planet bhi ek chamakdaar dot hai, aur star bhi. Yeh rahe do tests. Pehla, ek minute dhyaan se dekho. Stars twinkle (timtimate) karte hain: hamare upar chalti hawa unki roshni ko idhar-udhar mod deti hai, isliye woh jhilmilati hai. Planets aam taur par zyada steady roshni se chamakte hain. Doosra, kuch hafte dekhte raho. Planets dheere-dheere star patterns ke beech ghoomte rehte hain. Asal mein planet word ek Greek word se aaya hai jiska matlab hai wanderer, yaani ghoomne wala.

Venus ki ek khaas aadat hai. Sun ke chaaron taraf uska raasta Earth ke raaste ke andar hai. Isliye Earth se hum use aasmaan mein hamesha Sun ke kaafi paas dekhte hain. Isi wajah se Venus sirf suraj doobne ke baad ya ugne se pehle dikhta hai, kabhi aadhi raat ko nahi. Fig. 12.12 dikhata hai kyun.

1/3Suraj doobne ke theek baad Venus western sky mein neeche chamakta hai.

Fig. 12.12Venus shaam ya subah ka nazaara hai kyunki uska raasta Earth ke raaste ke andar hai.

Step one mein suraj doobne ke theek baad ka sandhya aasmaan hai, WEST dekho, horizon par garam chamak, do ped, kuch timtimate stars aur ek chamakdaar steady dot jiska label Venus hai. Step two mein waisa hi scene hai, EAST dekho, suraj ugne se theek pehle, aur chamak ke upar chamakdaar Venus. Step three upar se dekha gaya view hai: beech mein Sun, Venus ke raaste ke liye ek dashed circle aur Earth ke raaste ke liye ek bada dashed circle, aur right mein Earth. Earth se do lines Venus ke raaste ko bas chhooti hain, aur Sun ke aas-paas ek shaded wedge banati hain, aur ek note kehta hai ki Earth se dekhne par Venus Sun ke paas hi rehta hai.

Jupiter ki taraf binoculars karo. Tumhe uske bagal mein ek line mein chaar chhote dots dikh sakte hain: uske chaar sabse bade moons! Binoculars aur telescope tumhari aankh se kahin zyada roshni ikattha karte hain. Isliye unse planets bade aur zyada chamakdaar dikhte hain, aur aisi dhundhli cheezein bhi dikhti hain jo sirf aankhon se chhoot jaati. Ek chhota telescope bhi Saturn ke rings dikha deta hai.

Quick check
2 mein se 1
Sandhya ke samay tumhe roshni ke do chamakdaar points dikhte hain. Ek jhilmilata hai; doosra steady chamakta hai. Planet hone ke sabse zyada chances kiske hain?
Answer dekho

Answer (A) Steady wala

Stars isliye timtimate hain kyunki chalti hawa unki roshni ko mod deti hai. Planets aam taur par zyada steady chamakte hain. Kai raaton tak dekhne se bhi madad milti hai, kyunki planets stars ke beech khisakte rehte hain.

Natural satellites

Planets Sun ke chaaron taraf ghoomte hain. Kya planets ke chaaron taraf bhi kuch ghoomta hai? Haan. Hamari Earth ke paas Moon hai, aur Mars ke do chhote, aloo jaise saathi hain jinhe Phobos aur Deimos kehte hain. Jo body kisi planet ke chaaron taraf ghoomti hai use satellite (उपग्रह) kehte hain. Moons natural satellites hain. Har moon apne planet se chhota hota hai.

Mercury aur Venus ka ek bhi moon nahi hai. Chaar giants ke moons ki badi-badi families hain. Akele Saturn ke sau se bhi kaafi zyada moons hain!

Definition
Satellite

Aisi body jo kisi planet ya kisi doosri, bahut badi body ke chaaron taraf ghoomti hai.

ExampleMoon, Earth ka natural satellite hai.

Scientists kabhi-kabhi satellite word ko aur bade matlab mein use karte hain, kisi bhi chhoti body ke liye jo bahut badi body ke chaaron taraf ghoomti hai. Is rule se to Earth bhi Sun ka satellite hai! Log artificial satellites bhi banate hain. Indian Space Research Organisation (ISRO) ne aise kai satellites launch kiye hain. Yeh weather ka forecast karne, zameen ka map banane aur phone aur TV signals bhejne mein madad karte hain.

Moon

Space mein koi bhi natural body humse Moon jitni paas nahi hai, jo lagbhag 3,84,000 km door hai. Uski chaudai Earth ki chaudai ka sirf lagbhag ek-chauthai hai. Woh lagbhag 27 din mein Earth ka ek chakkar lagata hai, aur us par lagbhag koi hawa nahi hai. Kitabon mein page par fit karne ke liye Moon ko aksar bada aur Earth ke paas banaya jaata hai. Asli picture dekhne ke liye Fig. 12.13 ke steps dekho.

3/3Asli doori par Earth aur Moon ke beech lagbhag 30 Earths sama sakti hain.

Fig. 12.13Moon ki chaudai Earth ki chaudai ka lagbhag ek-chauthai hai, aur dono ke beech ke gap mein lagbhag 30 Earths sama sakti hain.

Step one mein ek badi neeli-hari Earth hai aur uske theek bagal mein usse aadhi chaudai ka grey Moon, saath mein note hai pictures mein aksar aise. Step two mein Moon chhota hokar Earth ki chaudai ka lagbhag ek-chauthai reh jaata hai, label hai Moon: ~¼ Earth ki chaudai. Step three mein dono chhote hokar door ho jaate hain: left mein chhoti Earth aur right mein dot jitna Moon, beech ke gap mein tees halki Earth outlines ki line hai, label kareeb 30 Earth, aur neeche ek double-headed arrow jiska label 3,84,000 km hai.

Example

Ek line mein Earths

Earth aur Moon lagbhag 3,84,000 km door hain, aur Earth lagbhag 12,742 km chaudi hai. Dono ke beech ke gap mein tum kitni Earths saath-saath line mein laga sakte ho?

Pehle khud try karo. Phir solution ek-ek step karke kholo.

Binoculars se Moon gaddhon bhara dikhta hai, jaise aate ki loi mein kai ungliyan gadaa di gayi hon. Yeh gol gaddhe craters hain. Bahut pehle space se aakar takraye pattharon aur asteroids ne inhe banaya tha. Earth se bhi aisi cheezein takrayi hain, par yahan hawa, baarish, nadiyan aur paudhe dheere-dheere un nishaanon ko mita dete hain. Moon par na hawa hai, na behta paani, na life. Isliye uske craters arabon saal tak bane rehte hain, aur 1969 ke astronauts ke pairon ke nishaan bhi aaj tak wahan hain.

Moon ko paas se study karne ke liye India ne Chandrayaan naam ke spacecraft ki ek series bheji hai, jiska matlab hai Moon craft, yaani chandrama ka yaan.

Timeline

India chala Moon par

  1. 2008

    Chandrayaan-1

    India ke pehle Moon mission ne Moon ke chakkar lagaye aur uski surface par paani ke nishaan dhoondhne mein madad ki.

  2. 2019

    Chandrayaan-2

    Iske orbiter ne upar se Moon ko study karna shuru kiya; lander utarne ki koshish mein contact kho baitha.

  3. 23 August 2023

    Chandrayaan-3 utra

    Vikram lander Moon ke south pole ke paas aaraam se utra aur usne Pragyan rover ko bahar bheja. India south pole ke paas utarne wala pehla desh bana.

  4. Har 23 August

    National Space Day

    India ab utarne ke din ko National Space Day ke roop mein manata hai.

  5. Aage ka plan

    Chandrayaan-4

    Ek aane wale mission ka plan hai jo Moon ki mitti aur patthar Earth par wapas laayega.

SimulationMoon ki badalti shape

Upar se dekha gaya view: Earth aur uske chaaron taraf ghoomta Moon, aur ek taraf se aati dhoop. Earth aur Moon dono ka ek roshan half Sun ki taraf hai. Ek panel dikhata hai ki Earth se Moon ki shape kaisi dikhti hai: Moon ke apne raaste par chalne ke saath woh patle crescent se poori disc tak badhti hai aur phir ghat jaati hai.

Fig. 12.14Sun hamesha Moon ke aadhe hisse ko roshan karta hai. Us half ka kitna hissa hum dekhte hain, yeh Moon ke Earth ka chakkar lagane ke saath badalta hai.
Try karo
  • Jab Moon, Earth aur Sun ke beech hota hai, to uske roshan half ka kitna hissa hamari taraf hota hai?
  • Jab hum poora, gol Moon dekhte hain, tab Moon kahan hota hai?
  • Kya Moon ka roshan half hamesha Sun ki taraf hota hai, ya hamesha Earth ki taraf?
Quick check
4 mein se 1
Moon ke baare mein sabse sahi baat kaunsi hai?
Answer dekho

Answer (A) Earth ka natural satellite, jo dhoop ko reflect karta hai

Moon, Earth ke chaaron taraf ghoomta hai, isliye woh Earth ka natural satellite hai. Woh sirf dhoop ko reflect karke chamakta hai; woh na star hai, na planet.

Asteroids aur comets

Sun aur planets ki pictures mein gol balls dikhti hain. Asteroids (क्षुद्रग्रह) alag hain: yeh patthar ke tukde hain jinki shapes oobad-khaabad, ulti-seedhi hoti hain, balls se zyada aaloo jaisi. Sabse chhote kuch metre ke hote hain; sabse bade kuch sau kilometre chaude.

Asteroids bhi Sun ke chaaron taraf ghoomte hain. Inmein se zyaadatar ek chaude ring mein rehte hain jise asteroid belt kehte hain, jo Mars aur Jupiter ke raaston ke beech hai. Ise planets ki line mein dhoondho. Kuch asteroids Sun ke zyada paas aa jaate hain aur kabhi-kabhi Earth ke paas se guzarte hain. Isi liye duniya bhar ke scientists un par dhyaan se nazar rakhte hain.

Kabhi-kabhi raat ke aasmaan mein lambi tail wali ek dhundhli roshni dikhti hai aur hafton tak rehti hai. Yeh ek comet (धूमकेतु) hai: ice, dhool aur patthar ka ek dhela, jo aam taur par sirf kuch kilometre chauda hota hai. Woh Solar System ke door, jame hue kinare se andar aaya hai. Sun ke paas aane par dhoop use garam karti hai, uski ice gas ban jaati hai, aur gas dhool ko saath le jaati hai. Isse comet ke chaaron taraf ek chamakta baadal aur ek lambi tail banti hai jo lakhon kilometre tak fail sakti hai.

Ek surprise suno: tail comet ke peeche waise nahi chalti jaise train ke peeche dhuan. Sun ki roshni aur Sun se aane wali particles ki hawa use dhakelti hai, isliye tail hamesha Sun se ulti taraf hoti hai. Jab comet jaata hai, to uski tail aage-aage chalti hai! Fig. 12.15 mein ek comet ko uske raaste par follow karo.

3/4Sun ke bilkul paas tail sabse lambi hoti hai, seedha Sun se ulti taraf.

Fig. 12.15Comet ki tail Sun ke paas aane par badhti hai aur hamesha Sun se ulti taraf hoti hai.NCERT Fig. 12.10 · p. 246

Ek lamba, oval dashed raasta, jiske left sire ke paas Sun hai aur chhote arrows chalne ki direction dikhate hain. Step one mein comet raaste ke bilkul right sire par hai, bina tail ka ek chhota barfeela dot, label jama, tail nahi. Step two mein woh raaste ke upar wale hisse se Sun ki taraf aa gaya hai aur ek chhoti tail Sun se ulti taraf hai, label tail banti. Step three mein woh left mein Sun ke bahut paas se guzarta hai aur uski tail sabse lambi hai, left ki taraf, seedha Sun se ulti taraf, label sabse lambi. Step four mein woh raaste ke neeche wale hisse se door jaata hai aur uski tail ab bhi Sun se ulti taraf, uske aage hai, label tail aage. Pichhli jagahein halki parchhaaiyon ki tarah dikhti rehti hain.

Aakhir mein comet ka kya hota hai? Kai comets lambe, oval raaston par Sun ke chakkar lagate rehte hain aur baar-baar laut kar aate hain. Kuch Solar System se bahar phenk diye jaate hain aur kabhi nahi lautte. Kuch tukdon mein toot jaate hain, ya Sun ya kisi planet se takra jaate hain. 1994 mein astronomers ne ek comet ke tukdon ko Jupiter se takraate dekha, jisse wahan poori Earth jitne chaude kaale nishaan ban gaye.

Yeh rahi poori family. Beech mein Sun hai, uske chaaron taraf aath planets aur unke moons, saath mein dwarf planets, asteroids aur comets. Socho ki poore Solar System ko ek giant taraazu par rakh diya. Akele Sun ka wazan har 100 hisson mein se 99 se zyada hoga. Woh akela member bhi hai jo apni roshni khud banata hai. Jo bhi planet, moon, asteroid aur comet hum dekhte hain, woh us par padkar laut-ti dhoop se roshan hai.

Flash cards · 6

Sun ki family se milo

1 / 6
Quick check
4 mein se 1
Zyaadatar asteroids kahan milte hain?
Answer dekho

Answer (A) Mars aur Jupiter ke raaston ke beech

Zyaadatar asteroids Mars aur Jupiter ke beech asteroid belt mein ghoomte hain. Kuch Earth ke paas se guzarte hain, aur kai barfeeli bodies Neptune ke aage hain, par zyaadatar pathreele asteroids belt mein hi hain.

12.4 Milky Way Galaxy

Bina chaand wali raat mein shehar ki lights se door jao, aur upar dekho. Aasmaan ke aar-paar ek halki, dhabbedaar patti jaati hai, jaise kohre ki nadi. Uski taraf binoculars karo, to kohra dhundhle stars ke jhundon mein toot jaata hai. Woh itne zyada aur itne door hain ki ek-ek karke nahi dikhte.

Kohre ki woh nadi hamari home galaxy hai, Milky Way Galaxy. India mein ise Akash Ganga kehte hain, yaani aasmaan ki Ganga. Galaxy stars ki ek bahut badi family hai, laakhon se lekar sau arab tak stars ki. Ismein gas aur dhool bhi hoti hai, aur iski har cheez space mein ek saath bandhi rehti hai. Milky Way mein 100 billion se zyada stars hain. Hamara Sun, apne planets ke saath, unmein se bas ek hai.

Definition
Galaxy

Laakhon se arabon stars ki ek bahut badi family, gas aur dhool ke saath, jo space mein ek saath bandhi rehti hai.

ExampleMilky Way, hamari home galaxy, aur uska bada padosi, Andromeda Galaxy.

Par hamari galaxy ek patti jaisi kyun dikhti hai? Milky Way ek chapti disc jaisi hai, kuch-kuch ek bahut badi ghoomti roti jaisi, aur hum us disc ke andar rehte hain. Jab hum disc ke saath-saath dekhte hain, to stars ke peeche stars dikhte hain: ek chamakti patti. Jab hum disc se bahar ki taraf dekhte hain, to bahut kam stars dikhte hain. Fig. 12.16 yeh idea dikhata hai.

2/3Bahut door bahar se hamari galaxy ek spiral jaisi dikhti. Sun centre se kuch door bahar ki taraf hai.

Fig. 12.16Hum stars ki ek chapti disc ke andar rehte hain. Disc ke saath-saath dekhne par hamein Milky Way ki patti dikhti hai.NCERT Fig. 12.11 · p. 247

Step one mein pahadiyon ke upar raat ka aasmaan hai, jismein dhundhle stars se bhari ek chaudi, dhundhli patti tirchhi jaati hai, label Milky Way aur Akash Ganga, aur ek note: andheri jagah, bina Moon. Step two mein galaxy bahar se, saamne se dikhti hai: chamakta sunehra centre aur stars ki chaar mudi hui spiral arms, aur centre se kuch bahar ek circle wala marker, label Sun: hum yahan. Step three mein galaxy kinare se dikhti hai, stars ki ek patli chapti line jiske beech mein ubhaar hai; Sun ke marker se ek arrow disc ke saath jaata hai, label bahut stars: patti, aur doosra arrow seedha disc se bahar jaata hai, label kam stars.

Quick check
2 mein se 1
Bahut andhere aasmaan mein dikhne wali halki, doodhiya patti kya hai?
Answer dekho

Answer (A) Hamari galaxy, uski disc ke andar se dekhi gayi

Yeh patti hamari apni galaxy ki disc ke anginat dhundhle stars ki roshni hai. Hum ise patti ki tarah isliye dekhte hain kyunki hum chapti disc ke andar hain.

12.5 Universe

Hamari galaxy ke aage kya hai? Aur galaxies: arabon galaxies, har ek mein apne laakhon ya arabon stars. Sabse paas wali badi galaxy, Andromeda Galaxy, itni door hai ki uski roshni ko humtak pahunchne mein lagbhag 25 lakh saal lagte hain. Bahut andheri jagah se tum use bas ek halke, dhundhle dhabbe ki tarah dekh sakte ho. Alag-alag umar aur shapes ki galaxies ko compare karke astronomers jod-jod kar samajh rahe hain ki stars aur galaxies kaise bante aur badalte hain.

Jo kuch bhi hai, poora space aur usmein har galaxy, star, planet aur dhool ka har kan, use Universe (ब्रह्मांड) kehte hain. Sab kuch saath rakho, to tumhe apna poora space address milta hai, jo Fig. 12.17 mein dikhaya gaya hai.

Definition
Universe

Jo kuch bhi hai: poora space aur usmein saari galaxies, stars, planets aur baaki bodies.

4/5Sun, Milky Way ke 100 billion se zyada stars mein se ek hai.

Fig. 12.17Space mein tumhara address, tumhare ghar se poore Universe tak.

Left mein paanch lines wala ek address card hai: Ghar, India; Planet Earth; Solar System; Milky Way Galaxy; Universe, jo chhote neeche ke arrows se jude hain. Har step mein agli line roshan hoti hai aur right ki picture badalti hai. Step one mein location pin ke saath ek ghar aur ped hai. Step two mein Earth hai jismein India par pin hai aur paas mein Moon. Step three mein Sun aur planets ke dashed raaste hain, aur Earth par circle hai. Step four mein ek spiral galaxy hai jismein Sun ki jagah par circle hai. Step five mein space mein bikhri kai chhoti galaxies hain, aur hamari galaxy par circle hai jiska label apni hai.

Hamara Sun akela star nahi hai jiske planets hain. Astronomers ko hamari galaxy mein doosre stars ke chaaron taraf ghoomte 5,000 se zyada planets mile hain, aur woh unhe exoplanets (बाह्यग्रह) kehte hain. Kya inmein se kisi par kuch zinda hai? Bade telescopes inmein se kuch duniyaon ke aas-paas ki hawa ko study kar rahe hain, aur water vapour jaise hints dhoondh rahe hain. Abhi tak life ka koi nishaan nahi mila, par khoj jaari hai.

Quick check
3 mein se 1
Inhe sabse chhote se sabse bade tak lagao.
  1. Universe
  2. Solar System
  3. Milky Way Galaxy
  4. Earth
Answer dekho
Answer
  1. Earth
  2. Solar System
  3. Milky Way Galaxy
  4. Universe
Earth, Solar System ka ek planet hai; Solar System, Milky Way ka ek chhota sa hissa hai; Milky Way, Universe ki arabon galaxies mein se ek hai.

Aur aage seekho

3/3Shehar bahut door hain, isliye unki chamak telescopes ke upar ke aasmaan tak mushkil se pahunchti hai.

Fig. 12.18Astronomers ko Hanle pasand hone ki teen wajahein: oonchaai, sookhi hawa aur andhera aasmaan.NCERT Aur jaano · p. 252

Taaron bhare aasmaan ke neeche pahadon ka ek scene. Right mein sabse oonchi choti par ek safed observatory dome hai, label Hanle, about 4,500 m. Left mein uske neeche chhote pahad aur do baadal hain. Step one mein label hai kai baadal neeche. Step two mein neeche ki hawa mein kai chhoti neeli paani ki boondein dikhti hain, jo upar jaate-jaate kam hoti jaati hain, isliye dome ke aas-paas ki hawa mein lagbhag koi boond nahi hai; label hai patli, sookhi hawa. Step three mein left kinare par bahut door orange chamak wala ek chhota shehar dikhta hai, upar ke dhundhle stars aur saaf ho jaate hain, aur label hai city lights se door.

Quick check
2 mein se 1
Astronomers ne observatory ke liye Hanle kyun chuna?
Answer dekho

Answer (B) Yeh oonchi, sookhi aur shehar ki lights se door jagah hai

Oonchaai telescopes ko zyaadatar baadalon se upar rakhti hai, sookhi hawa starlight ko kam dhundhla karti hai, aur andhere aasmaan mein dhundhli cheezein dikhti hain. Bada shehar light pollution laata, aur baarish ka matlab hai baadal wali raatein.
Recap

Summary aur key points

  1. Stars garam, chamakti gas ke bahut bade gole hain jo apni roshni khud banate hain. Sun hamara sabse paas ka star hai (Section 12.1).
  2. Log stars ko jod kar imaginary patterns banate hain. Aaj aasmaan 88 constellations mein bata hai, jaise Orion, Canis Major aur Taurus (Section 12.1).
  3. Big Dipper ke do pointer stars Pole Star tak le jaate hain, jo north ke upar lagbhag ruka rehta hai aur northern hemisphere mein direction pata karne mein hamari madad karta hai (Fig. 12.4).
  4. Orion's belt, Sirius ki taraf ishaara karti hai, jo raat ke aasmaan ka sabse chamakdaar star hai (Fig. 12.3).
  5. Light pollution dhundhle stars ko chhupa deta hai. Aasmaan kisi andheri jagah se, kisi bade ke saath, aankhon ko adjust hone ka time dekar dekho (Section 12.2).
  6. Sun lagbhag 150 million km (1 au) door ek star hai. Uski roshni aur heat humein garam rakhti hai, paudhon ko khaana deti hai aur weather aur water cycle chalati hai (Sun).
  7. Planet ek bada, gol body hai jo Sun ke chaaron taraf ghoomta hai aur reflect hui dhoop se chamakta hai. Earth lagbhag ek saal mein Sun ke chaaron taraf ek revolution karti hai (Planets).
  8. Sun se order mein: Mercury, Venus, Earth aur Mars (rocky), phir Jupiter, Saturn, Uranus aur Neptune (gas aur ice ke giants, rings ke saath) (Fig. 12.10).
  9. Venus sabse chamakdaar planet hai aur subah ya shaam ke aas-paas dikhta hai. Stars timtimate hain; planets zyada steady chamakte hain (Planets dhoondhna).
  10. Planets ke chaaron taraf ghoomne wali bodies satellites hain. Moon, Earth ka natural satellite, lagbhag 27 din mein uska chakkar lagata hai aur craters se bhara hai (Moon).
  11. Asteroids pathreele dhele hain, zyaadatar Mars aur Jupiter ke beech. Sun ke paas comet ki tail banti hai, aur tail hamesha Sun se ulti taraf hoti hai (Asteroids aur comets).
  12. Sun, planets, moons, asteroids aur comets milkar Solar System banate hain, jo Milky Way Galaxy ka hissa hai (Section 12.4).
  13. Universe mein arabon galaxies hain. Exoplanets doosre stars ke chaaron taraf ghoomte hain, par Earth ke bahar abhi tak life nahi mili hai (Section 12.5).
Practice · 17 questions

Practice questions answers ke saath (NCERT “Chalo, apni samajh aur badhayein”)

Sawaal 1 se 11 wahi skills practise karate hain jo NCERT exercises; 12 se 17 extra practice hain.

  1. Quick answerEasyNCERT Exercises Q1

    Har description ko sahi naam se match karo.

    Left mein koi item tap karo, phir right mein uska match.

    Answer dekho
    Answer
    • Sabse chaude, sabse chamakdaar rings wala planet : Saturn
    • Raat ke aasmaan ka sabse chamakdaar star : Sirius
    • Woh star jo batata hai ki north kis taraf hai : Pole Star
    • Star pattern jise shikaari ki tarah dikhaya jaata hai : Orion
    • Woh planet jiska nickname Blue Planet hai : Earth
    Saturn ke rings sabse chamakdaar hain; Sirius raat ka sabse chamakdaar star hai; Pole Star north batata hai; Orion shikaari hai; Earth apne samudron ki wajah se neeli dikhti hai.
  2. Short answerMediumNCERT Exercises Q2

    Letter paheliyan.

    1. Mera pehla letter VAN mein hai par PAN mein nahi. Mera doosra EGG mein hai par PIG mein nahi. Mera teesra NET mein hai par TEA mein nahi. Mera chautha SUN mein hai par SON mein nahi. Mera paanchvaan SKY mein hai par KEY mein nahi. Main tumhare aasmaan ka sabse chamakdaar planet hoon. Main kaun hoon?

      Answer dekho

      Answer Venus

      V (van, pan nahi), E (egg, pig nahi), N (net, tea nahi), U (sun, son nahi), S (sky, key nahi): VENUS, sabse chamakdaar planet.

    2. Isi tarah apni do paheliyan banao: ek kisi planet ke liye aur ek Solar System ke kisi aur member ke liye.

      Solution dikhao

      Kai answers ho sakte hain. Yeh rahe do examples.

      • Mera pehla MAT mein hai par CAT mein nahi. Mera doosra COT mein hai par CUT mein nahi. Mera teesra DOG mein hai par DIG mein nahi. Mera chautha PEN mein hai par PET mein nahi. Main lagbhag 27 din mein Earth ka ek chakkar lagata hoon. (MOON)
      • Mera pehla CUP mein hai par PUP mein nahi. Mera doosra HOT mein hai par HAT mein nahi. Mera teesra MAP mein hai par CAP mein nahi. Mera chautha BED mein hai par BAD mein nahi. Mera paanchvaan TOP mein hai par POP mein nahi. Sun ke paas aane par meri tail ban jaati hai. (COMET)
  3. Quick answerEasyNCERT Exercises Q3

    Inmein se kaun hamare Solar System ka hissa nahi hai?

    Answer dekho

    Answer (C) Pole Star

    Pole Star ek door ka star hai, Solar System se bahut bahar. Comet, Mars ka moon aur asteroid, sab Sun ke chaaron taraf ghoomte hain, seedhe ya apne planet ke saath.
  4. Quick answerEasyNCERT Exercises Q4

    2004 ka ek purana school poster nau planets dikhata hai. Aaj scientists inmein se kise planet nahi kahenge?

    Solution dikhao

    Kai saalon tak Pluto ko nauvaan planet kaha gaya. Jab Neptune ke aage waise hi kai chhote barfeele bodies mile, to astronomers ne saaf rules banaye ki planet kya hai. Pluto un rules par khara nahi utra, isliye 2006 se woh ek dwarf planet hai. Ab Sun ke aath planets hain.

  5. Short answerEasyNCERT Exercises Q5

    Aman kehta hai: Sailors raasta dhoondhne ke liye Pole Star use karte the, to woh aasmaan ka sabse chamakdaar star hi hoga.

    1. Kaun zyada chamakdaar hai?

      Answer dekho

      Answer (A) Sirius

      Sirius raat ke aasmaan ka sabse chamakdaar star hai. Pole Star bas medium-chamakdaar hai.

    2. Samjhao ki Aman kahan galat hai.

      Solution dikhao

      Aman ne do ideas mila diye hain. Sirius, Pole Star se bahut zyada chamakdaar hai. Sailors ne Pole Star ko uski chamak ki wajah se nahi chuna tha. Unhone use isliye chuna kyunki baaki stars chalte rehte hain par woh north ke upar lagbhag ruka rehta hai, isliye woh hamesha ek hi direction dikhata hai.

  6. Quick answerEasyNCERT Exercises Q6

    Ek artist ne poster par planets ka order gadbad kar diya hai. Unhe sahi order mein lagao, Sun ke sabse paas wale se shuru karke.

    1. Mars
    2. Jupiter
    3. Neptune
    4. Uranus
    5. Earth
    6. Mercury
    7. Venus
    8. Saturn
    Answer dekho
    Answer
    1. Mercury
    2. Venus
    3. Earth
    4. Mars
    5. Jupiter
    6. Saturn
    7. Uranus
    8. Neptune
    Pehle chaar rocky planets aate hain (Mercury, Venus, Earth, Mars), phir chaar giants (Jupiter, Saturn, Uranus, Neptune).
  7. DiagramMediumNCERT Exercises Q7

    Fig. 12.2 mein Northern sky kholo. Iske stars Fig. 12.4 se alag ghoome hue hain, bilkul waise jaise asli aasmaan raat bhar ghoomta hai. Agar tum sketchpad use nahi kar sakte, to ek northern star chart kaagaz par copy kar lo.

    1. Big Dipper kitne chamakdaar stars se bana hai?

      stars
      Answer dekho

      Answer 7 stars

      Chaar stars bowl banate hain aur teen handle: kul saat.

    2. Big Dipper aur Little Dipper ke stars jodo, aur Pole Star par label lagao. Phir check karne ke liye Show answer dabao.

      Solution dikhao

      Chaar stars ka bowl aur teen ka handle dhoondho. Bowl ke bahar wale kinare ke do stars pointer stars hain. Unse jaati line par, bowl se door, lagbhag paanch gap aage jao. Jis medium-chamakdaar star par pahunchte ho, woh Pole Star hai. Little Dipper usse latakta hai: Pole Star uske handle ka sira hai. Uska dhundhla bowl usi taraf hai jis taraf Big Dipper ka handle.

  8. DiagramMediumNCERT Exercises Q8

    Fig. 12.2 mein Winter sky kholo, ya sardiyon ka star chart use karo.

    1. Orion ke stars jodo aur Sirius par label lagao. Phir check karne ke liye Show answer dabao.

      Solution dikhao

      Pehle ek chhoti seedhi line mein belt ke teen stars dhoondho. Unke aas-paas ke chaar chamakdaar stars shikaari ke kandhe aur ghutne hain: unhe belt se jodo. Phir belt ki line ko neeche ki taraf follow karo jab tak chart ka sabse chamakdaar star na mil jaaye: Canis Major mein Sirius.

    2. Orion se Sirius tak pahunchne ke liye kis taraf jaate ho?

      Answer dekho

      Answer (A) Belt ki line ke saath

      Belt ek pointer hai. Uski line ko neeche follow karo to Sirius; doosri taraf follow karo to Taurus ka Aldebaran.
  9. Short answerMediumNCERT Exercises Q9

    December ki ek subah Riya jaldi wali train pakadti hai. Subah 5 baje station ke upar stars timtima rahe hain. Subah 7 baje tak, jab train chalti hai, aasmaan chamakdaar neela hai aur ek bhi star nahi bacha. Stars kahan gaye? Samjhao ki Riya ne kya dekha.

    Solution dikhao

    AnswerStars poore din aasmaan mein hi hote hain; din ka chamakdaar aasmaan unhe chhupa deta hai.

    Stars kabhi switch off nahi hote, na kahin jaate hain. Din mein dhoop hawa ko roshan kar deti hai, jisse poora aasmaan chamakdaar neela chamakta hai. Stars ki dhundhli roshni is chamak ke saamne kho jaati hai.

    Subah aasmaan chamakne par sabse dhundhle stars sabse pehle gaayab hote hain aur sabse chamakdaar sabse baad mein. Shaam ko order ulta hota hai. Total solar eclipse mein Moon kuch minute ke liye Sun ko dhak leta hai. Aasmaan andhera ho jaata hai, aur din ke beech mein chamakdaar stars dikh jaate hain.

  10. ActivityMediumNCERT Exercises Q10

    March aur June ke beech ek saaf shaam chuno. Raat 8 baje, 10 baje aur aadhi raat ko northern sky dekho. Har baar Big Dipper aur Pole Star ka sketch banao, marker ki tarah kisi ped ya chhat ka sira banao, aur sketch ke bagal mein time likho.

    1. Tumhe kya lagta hai, tumhare sketches kya dikhayenge?

      Answer dekho

      Answer (C) Big Dipper, Pole Star ke chaaron taraf ghoomta hai, aur Pole Star lagbhag ruka rehta hai

      Poora aasmaan Pole Star ke chaaron taraf ghoomta lagta hai, isliye Big Dipper uske chaaron taraf circle mein chalta hai jabki Pole Star mushkil se hilta hai.

    2. Aasmaan Pole Star ke chaaron taraf har ghante lagbhag 15° ghoomta lagta hai. Raat 8 baje se aadhi raat tak Big Dipper kitne degree ghoom chuka hoga?

      degrees
      Answer dekho

      Answer 60 degrees

      Raat 8 baje se aadhi raat tak 4 ghante hain, aur 4 × 15° = 60°: poore circle ka chhatha hissa.

    3. Batao ki Big Dipper kaise chalta hai, aur samjhao kyun.

      Solution dikhao

      Har sketch mein Big Dipper ek nayi jagah hai. Woh ghadi ki sui ki tarah Pole Star ke chaaron taraf ghoomta hai, par anticlockwise, har do ghante mein lagbhag circle ka barahvaan hissa. Pointer stars hamesha Pole Star ki taraf ishaara karte rehte hain, aur Pole Star tumhare marker ke paas hi rehta hai. Stars sach mein hamare chaaron taraf chakkar nahi laga rahe. Earth rotate kar rahi hai, aur isi se poora aasmaan north ke upar wale point ke chaaron taraf ghoomta lagta hai.

  11. Long answerEasyNCERT Exercises Q11

    Raat ke aasmaan par ek chhoti kavita ya kahaani likho. Usmein is chapter ke kam se kam teen facts daalo, jaise Venus kyun chamakta hai ya comet ki tail kis taraf hoti hai.

    Solution dikhao

    Tumhari kavita ya kahaani tumhari apni hogi. Yeh ek example hai jismein chapter ke chaar facts hain.

    • Light chali gayi, chhat par andhera chhaaya,
    • to aasmaan mele jaisa jagmagaaya.
    • Saptarishi ghoomte Dhruva tare ke paas,
    • Orion ki belt dikhaati Sirius, chamakta khaas.
    • West mein neeche Venus chamke, bilkul na timtimaaye;
    • Sun se roshni udhaar le, jaise har planet chamak paaye.
    • Ek comet aata hai, tail failaaye lambi-chaudi,
    • jo hamesha Sun se ulti taraf hi mudi.
  12. Quick answerEasy

    Inmein se kaun natural satellites hain? Jitne sahi hain, sab chuno.

    Saare sahi options chuno
    Answer dekho
    Answer
    • (A) Moon
    • (B) Phobos
    Moon (Earth ke chaaron taraf) aur Phobos (Mars ke chaaron taraf) natural satellites hain. Weather satellite artificial hai, aur Venus ek planet hai jiska koi moon nahi.
  13. Quick answerEasy

    Earth ke Sun ke chaaron taraf ek poore chakkar ko kehte hain, aur ismein lagbhag ek lagta hai.

    Answer dekho

    Answer (1) revolution, (2) year

    Earth lagbhag ek saal (lagbhag 365 din) mein Sun ke chaaron taraf ek revolution karti hai.
  14. Quick answerEasy

    Uranus aur Neptune sirf aankhon se aasaani se dikh jaate hain.

    Answer dekho

    Answer Galat

    Sirf Mercury, Venus, Mars, Jupiter aur Saturn hi sirf aankhon se dikhte hain. Uranus aur Neptune bahut door aur bahut dhundhle hain.
  15. NumericalMedium

    Sun, Earth se lagbhag 109 guna chauda hai. Class chart par tum Earth ko 2 cm chauda circle banate ho. Sun ko kitne centimetre chauda banana chahiye?

    cm
    Answer dekho

    Answer 218 cm

    2 cm × 109 = 218 cm: darwaaze se bhi ooncha! Isi liye zyaadatar charts Sun aur planets ko asli size mein nahi dikha sakte.
  16. Quick answerMedium

    Ek town chahta hai ki uske log raat mein zyada stars dekhein. Kaunsa badlaav sabse zyada madad karega?

    Answer dekho

    Answer (D) Streetlights par aise shields lagana jo roshni neeche bhejein

    Dhake hue lamps roshni ko aasmaan mein upar bhejne ki jagah zameen par bhejte hain, jahan logon ko chahiye. Tez lamps aur chhat ki lights aasmaan ko aur chamka deti.
  17. Quick answerHard

    Inhe Earth se sabse paas se sabse door ke order mein lagao.

    1. Moon
    2. Sun
    3. Proxima Centauri
    4. Neptune
    Answer dekho
    Answer
    1. Moon
    2. Sun
    3. Neptune
    4. Proxima Centauri
    Moon humse lagbhag 3,84,000 km door hai aur Sun lagbhag 15 crore km. Neptune, Sun se lagbhag 30 guna zyada door hai, aur Proxima Centauri lagbhag 2,69,000 guna zyada door.

Apna NCERT exercise question dhoondo

Hamare practice questions ncert.ai ke liye likhe gaye hain aur NCERT exercises ko follow karte hain. Apni textbook ke question se match karne wala question dhoondo; uska answer uske saath hai.

Tumhari NCERT textbook meinYahan practice question
NCERT Exercises Q1Practice Q1
NCERT Exercises Q2Practice Q2
NCERT Exercises Q3Practice Q3
NCERT Exercises Q4Practice Q4
NCERT Exercises Q5Practice Q5
NCERT Exercises Q6Practice Q6
NCERT Exercises Q7Practice Q7
NCERT Exercises Q8Practice Q8
NCERT Exercises Q9Practice Q9
NCERT Exercises Q10Practice Q10
NCERT Exercises Q11Practice Q11

Quick check: MCQs

  1. Upar dekho2 questions
  2. 12.1 Stars aur Constellations4 questions
  3. 12.2 Raat ka Aasmaan Dekhna4 questions
  4. Sun4 questions
  5. Planets4 questions
  6. Aasmaan mein planets dhoondhna2 questions
  7. Moon4 questions
  8. Asteroids aur comets4 questions
  9. 12.4 Milky Way Galaxy2 questions
  10. 12.5 Universe3 questions
  11. Aur aage seekho2 questions
Glossary · 15

Key terms (English + Hindi)

asteroidक्षुद्रग्रहkshudragrah
Ek chhoti, pathreeli, oobad-khaabad body jo Sun ke chaaron taraf ghoomti hai, zyaadatar Mars aur Jupiter ke raaston ke beech.Chapter mein pehli baar yahan aaya →
astronomical unit (au)खगोलीय इकाईkhagoleeya ikaai
Doori ka ek unit jo Earth aur Sun ke beech ki average doori ke barabar hai, lagbhag 150 million km.Chapter mein pehli baar yahan aaya →
cometधूमकेतुdhoomketu
Ice, dhool aur patthar ka ek dhela jo Sun ke chaaron taraf ghoomta hai. Sun ke paas uski ice gas ban jaati hai aur ek chamakti tail banati hai.Chapter mein pehli baar yahan aaya →
constellationतारामंडलtaaraamandal
Stars ka ek group jo pattern banata lagta hai, ya us pattern ke aas-paas ka aasmaan ka area. Aasmaan aise 88 hisson mein bata hai.Chapter mein pehli baar yahan aaya →
exoplanetबाह्यग्रहbaahyagrah
Aisa planet jo hamare Sun ke alawa kisi aur star ke chaaron taraf ghoomta hai.Chapter mein pehli baar yahan aaya →
galaxyमंदाकिनीmandaakini
Laakhon se arabon stars ki ek giant family, gas aur dhool ke saath, jo space mein ek saath bandhi rehti hai. Hamari galaxy Milky Way hai.Chapter mein pehli baar yahan aaya →
light pollutionप्रकाश प्रदूषणprakaash pradooshan
Raat mein bahut zyada artificial light, jo aasmaan ko chamka deti hai aur dhundhle stars ko chhupa deti hai.Chapter mein pehli baar yahan aaya →
planetग्रहgrah
Ek bada, gol body jo apne raaste par Sun ke chaaron taraf ghoomta hai aur apni roshni khud nahi banata.Chapter mein pehli baar yahan aaya →
Pole Starध्रुव ताराdhruv taara
Ek star jo northern sky mein lagbhag ruka rehta hai jabki baaki stars uske chaaron taraf ghoomte hain, isliye woh batata hai ki north kis taraf hai.Chapter mein pehli baar yahan aaya →
revolutionपरिक्रमणparikraman
Kisi body ka doosri body ke chaaron taraf ek poora chakkar, jaise Earth ka lagbhag ek saal mein Sun ka ek chakkar.Chapter mein pehli baar yahan aaya →
rotationघूर्णनghoornan
Apne axis par ghoomna. Earth ka ek rotation lagbhag 24 ghante mein hota hai aur isse din aur raat hote hain.Chapter mein pehli baar yahan aaya →
satelliteउपग्रहupagrah
Aisi body jo kisi planet ya kisi doosri badi body ke chaaron taraf ghoomti hai. Moon ek natural satellite hai.Chapter mein pehli baar yahan aaya →
Solar Systemसौर मंडलsaur mandal
Sun aur uske chaaron taraf ghoomne wali har cheez: aath planets, unke moons, dwarf planets, asteroids aur comets.Chapter mein pehli baar yahan aaya →
starताराtaara
Bahut garam, chamakti gas ka ek bahut bada gola jo apni roshni aur heat khud banata hai. Sun hamara sabse paas ka star hai.Chapter mein pehli baar yahan aaya →
Universeब्रह्मांडbrahmaand
Jo kuch bhi hai: poora space aur usmein saari galaxies, stars, planets aur baaki bodies.Chapter mein pehli baar yahan aaya →

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