We get mesmerized to see the twinkling stars, moon and planets in the clear night sky. But, all these will not be visible during day due to bright sunlight. They get hide in the brightness of sunlight. The sun, the moon, stars, planets and other objects that we see in the sky are called heavenly bodies or celestial objects. Those celestial bodies which emit heat and light of their own are called stars. The stars appear to move from east to west due to the rotation of the earth from west to east.
These heavenly bodies are clearly visible by a device called telescope. The branch of science in which we study about various celestial bodies is called astronomy. No one knows the size of universe. As per scientific research the universe is regularly expanding.
In large cities the watching of stars may be fainted because of bright lights, smoke and dust.
Galaxies– The group of billions of stars is called as galaxy. e. g.- Milky way (Akash Ganga)- it is a spiral galaxy that looks like a white band across the sky. The sun, the earth, other planets of solar system and many stars are part of milky way.
How to measure the distances in the universe?
The distances among celestial bodies are so large that it cannot be measured in kilometer. We use an astronomical distance measuring unit called light year. The speed of light is 3 X 108 m/s. So, light year is the distance travelled by the light in one year.
1light year = 3 X 108 X365 X 24 X 60 X 60s m/s
= 9.5 X 1012 km
The parsec (Symbol-PC) is an astronomical length used to measure very large distances between celestial objects outside solar system.
1 Parsec= 3.26 light Year
The nearest star to the earth is the sun. The distance between the earth and sun is 15 X 107 Km. The sunlight takes 500 seconds or 8 minute 20 second to reach to the earth. The second nearest star to the earth after the sun is ‘Proxima Centauri’. It is at a distance of 4.2 light years. It means the light that we can see from this star is 4.2 years old.
The Moon- The celestial body that revolves around the planets is called as moon or natural satellite. There are different numbers of moons to different planets of the solar system. The earth has only one moon. It revolves around the earth in about 27.3 days. It also rotates around its axis in the same period of time.
Fig-Phases of Moon (Source-http://www.astronomy.ohio-state.edu/)
The solar system and planets-The sun is a medium size closest star to the planet earth. It is made up of hydrogen and helium like gases. The nuclear fusion reaction in the sun is the cause of heat produced by the sun. The temperature of the core is 14 million degree celsius. At the surface the temperature is 6400 degree celsius. The diameter of the sun is about 1.4 million Km. It is 110 times more than the earth. The sun is the ultimate source of energy on the earth.
There are eight planets in the solar system. The planets and their moons constitute the solar system. ‘Pluto’ was too small to be called as planet. So, it was removed from the planets of solar system in 2006.
Those celestial objects which revolve around the sun are called planets. They do not have their own light and reflect the light of sun. They are close to earth, therefore, their reflected light does not go under much refraction and they do not twinkle. They are smaller than stars. They are made up of rocks and gases. The time taken by the planet to complete one revolution is called ‘period of revolution’. The planets rotate on their own axis also along with revolution around the sun. The time taken to complete one rotation on its axis is called ‘period of rotation’. The planets revolve around the sun in a definite pathway called ‘orbit’.
The four planets close to the sun are called inner planets. e.g.- Mercury, Venus, Earth and Mars. The four far away from the sun are called outer planets. e.g.- Jupiter, Saturn, Uranus and Neptune.
1. Mercury (Budh)-It is the closest planet to the sun. It is the smallest planet of solar system. It is difficult to observe it during daytime because of glare of the sun. It can be seen just before the sunrise and after sunset near the horizon. Mercury has no natural satellite. Its gravity is low so it cannot hold the atmosphere. There is no atmosphere on the mercury. So, the temperature varies between -200 ˚ C to 400˚C.
2. Venus (Shukra)-It is closest planet to the earth and almost of same size to the earth. There is atmosphere on the Venus having carbon dioxide gas. So, the temperature rises upto 480 ˚C. It reflects most of the sunlight. So, it is the brightest star of solar system. It can be seen before the sunrise and after sunset. It is also called as ‘morning star’ (for 292 days in eastern horizon) and ‘evening star’ (for 292 days in western horizon) although it’s a planet. Unlike other planets Venus rotates on its axis from east to west.
3. Earth (Prithvi)- Earth is a moderately hot planet where life exists. The presence of gases like oxygen and carbon dioxide helped in origin and existence of life on earth. There is presence of water and ozone layer in the atmosphere that stops absorbs harmful UV (Ultraviolet) rays coming on earth from the sun. It appears bluish-green from the outer space. The earth rotates around an imaginary axis that is inclined at an angle of 23 ½ ˚.
The equator divides the earth into two hemispheres-northern and southern hemispheres. When northern hemisphere is inclined towards the sun then there is summer season in northern hemisphere and winter in southern hemisphere. Similarly, when southern hemisphere is inclined towards the sun then there is summer season in southern hemisphere and winter in northern hemisphere.
On 21st March, the length of day and night is same. It is also called ‘Vernal equinox’ or ‘March equinox’. During this time, there will be spring season in northern hemisphere while autumn season in southern hemisphere. After this, the day starts to become longer and night starts to become shorter in northern hemisphere. It continues till 21st June or ‘Summer solstice’. It will be longest day of year. After this, days start to become shorter and nights start to become longer in northern hemisphere.
On 23rd September, length of day and night become same. It is also called ‘Autumnal equinox’ or ‘September equinox’. During this time there will be autumn season in the northern hemisphere and spring season in the southern hemisphere. After this, the day starts to become shorter and night starts to become longer in northern hemisphere. It continues till 22nd December or ‘Winter solstice’. It will be shortest day of year. After this, days start to become shorter and nights start to become longer in northern hemisphere.
On two days in a year, 21st March and 23rd September the sun rises exactly in the east direction. On all other days, the sun rises either north of east or south of east.
The term solstice means either most sunlight of the year (summer solstice) or least sunlight of the year (winter solstice) except equator.
4. Mars (Mangal)- It is about half in size of earth and called as red planet also. It’s very thin atmosphere has mostly carbon dioxide gas and water vapour. It temperature ranges from -120 ˚C to -25 ˚C. It has a rocky surface of creators and mountains. The largest volcano and longest canyon are found on the mars. There are two moons of mars.
5. Jupiter (Brihaspati)-It is the largest planet of the solar system. It’s volume is 1300 times to the earth and its weight is about 318 times to the earth. Its diameter is about eleven times to that of the earth. It has a gigantic rotating storm called ‘Great Red Spot’. Jupiter rotates (spins) on its axis faster than any other planet. Jupiter has 72 natural satellites.
6. Saturn (Shani)- It I the second largest planet of the solar system. It has three beautiful rings made up of ice and dust. Its surface is made up of liquid and gases. It has 53 moons. E.g.- Titan, Hyperion , Phoebe etc.
7. Uranus( Indra) – It is made up of hydrogen , helium and methane like gases. It appears blue-green because of very low temperature that condenses methane gas. Like Venus, it also rotates from east to west direction. It is third largest planet. It has 27 moons.
8. Neptune (Varun)-It is the fourth largest planet of solar system. It atmosphere is made up of hydrogen, helium and methane. It appears blue in colour because the red light is absorbed by methane and blue light is mainly scattered. It is also called as ‘Blue Giant’. Its diameter is about four times to the earth. It has 14 moons.
Constellations- A group of stars that has a recognizable shape or pattern is called a constellation. Ancient people started identifying the shapes of constellation. The shapes of constellations resemble the objects familiar to ancient people like animals and mythological characters. There are 88 known constellations. e. g.-Great Bear, Orion, Cassiopeia, Leo major, Capricorn etc.
1. Ursa Major/ Big Dipper/ Great Bear/ Saptarshi/ Seven sages– There are seven prominent stars in this constellation. Its shape is like a big ladle or a question mark. There are 4 stars in the bowl and 3 stars in the ladle. It can be seen in northern sky during summer season in a clear moonless night. In north direction to the two last stars of bowl, there is a bright star called pole star (Dhruvtara). It is about five times the distance between the distance of the two stars of bowl.
Due to the rotation of the earth, the Ursa Major appears to move around the pole star from east to west.
2. Orion/Hunter-This is a very magnificent constellation in southern sky. It can be seen during winter season in late evening. It has 7-8 bright stars. The 3 middle stars represent a belt of a hunter.
The four other bright stars form a shape of a quadrilateral. In the east direction of the belt of Orion, there is a bright star called Sirius.
3. Cassiopeia– It is a prominent constellation in northern sky. It is visible during winter in late evening. Its shape is like distorted ‘W’ or ‘M’.
Artificial Satellites-They are manmade objects that revolve around the earth much closer to the moon. The speed of revolution of artificial satellites is as same as the speed rotation the earth. The artificial satellites are used for telecommunications, radio and television broadcasting, weather forecasting, marine study, defence, education etc.
e.g.- Aryabhat, EDUSAT, Kalpana-1, IRS, INSAT etc.
Q.1 Which of the following is NOT a member of the solar system?
(a) An asteroid (b) A satellite
(c) A constellation (d) A comet
Ans- (c) A constellation
Q.2 Which of the following is NOT a planet of the sun?
(a) Sirius (b) Mercury
(c) Saturn (d) Earth
Q.3 Phases of the moon occur because
(a) we can see only that part of the moon which reflects light towards us.
(b) our distance from the moon keeps changing.
(c) the shadow of the Earth covers only a part of moon’s surface.
(d) the thickness of the moon’s atmosphere is not constant.
Ans-(a) we can see only that part of the moon which reflects light towards us.
Q.4 Fill in the blanks:
(a) The planet which is farthest from the Sun is …………………
(b) The planet which appears reddish in colour is ………………
(c) A group of stars that appears to form a pattern in the sky is known as a …………….
(d) A celestial body that revolves around a planet is known as ………………….
(e) Shooting stars are actually not …………………..
(f) Asteroids are found between the orbits of ……………. and …………………..
Ans- (a) Neptune (b)Mars (c) constellation (d) natural satellite (e) stars (f) Mars, Jupiter
Q.5 Mark the following statements as true (T) or false (F):
(a) Pole Star is a member of the solar system. ( )
(b) Mercury is the smallest planet in the planet in the solar system. ( )
(c) Uranus is the farthest planet in the solar system. ( )
(d) INST is an artificial satellite. ( )
(e) There are nine planets in the solar system. ( )
(f) Constellation Orion can be seen only with a telescope. ( )
Ans. (a) F , (b) T , (c) F , (d) T , (e) F , (f) F
Q.6 Match item in column A with one or more item in Column B:
Column A Column B
(i) Inner Planet (a) Saturn
(ii) Outer Planet (b) Pole Star
(iii)Constellation (c) Great Bear
(iv) Satellite of the earth (d) Moon
Ans- (i)- (e) Earth,(g) Mars (ii)-(a) Saturn (iii)- (c) Great Bear, (f) Orion (iv)- (d) Moon
Q.7 In which part of the sky can you find Venus if it is visible as an evening star?
Ans- It appears as the evening star in the western sky just after the sunset.
Q.8 Name the largest planet of the solar system.
Q.9 What is a constellation? Name any two constellations.
Ans-A constellation is a group of stars that make an imaginary shape in the night sky. Name of two constellations are- Ursa Major and Orion
Q.10 Draw sketches to show the relative positions of prominent stars in
(a) Ursa major and (b) Orion
Q.11 Name two objects other than planets which are members of the solar system.
Ans- The Moon and Asteroids
Q.12 Explain how you can locate the pole star with the help of Ursa Major.
Ans- First of all one has to locate the Ursa Major in northern sky during summer season in a clear moonless night. There are 4 stars in the bowl and 3 stars in the ladle. In north direction to the two last stars of bowl, there is a bright star called pole star (Dhruvtara). It is about five times the distance between the distance of the two stars of bowl of Ursa Major. It appears that Ursa Major is rotating around the Pole Star.
Q.13 Do all the stars in the sky move? Explain.
Ans- No, Pole star does not appear to move. It is because the Pole Star is situated close to the direction of the axis of rotation of the earth. So, it appears stationary.
Q.14 Why is the distance between stars expressed in light years? What do you understand by the statement that a star is eight light years away from the earth?
Ans- The distance between stars is very large. It is inconvenient to express such a large distance in kilometers (km.).So, light year is used to measure the distance between celestial bodies.
A star is eight light years away from the earth means the distance between the star and the earth is eight light years away.
The distance between the earth and that star is = 8 X 9.5 X 1012 km =7.6 X 1013 km.
Q.15 The radius of Jupiter is 11 times the radius of the Earth. Calculate the ratio of the volumes of Jupiter and the Earth. How many Earths can Jupiter accommodate?
Ans- Suppose, Radius of the Earth = r
So, radius of the Jupiter= 11 r
The volume of Earth= 4/3 π (r)3 and The volumes of Jupiter =4/3 π (11r)3
The ratio of the volumes of Jupiter and the Earth=4/3 π (11r)3/4/3 π (r)3
Q.16 Boojho made the following sketch of the solar system. Is the sketch correct? If not, correct it.
Ans- No, the sketch in the question is not correct. The positions of Mars, Venus, Uranus and Neptune are incorrect. The position of asteroids is also incorrect. The correct sketch is as like-
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Tunashangazwa sana kuona nyota, mwezi, na sayari zikitetemeka katika anga safi usiku. Lakini, hizi zote hazitaonekana wakati wa mchana kwa sababu ya mwangaza mkali wa jua. Wao kujificha katika mwangaza wa jua. Jua, mwezi, nyota, sayari na vitu vingine ambavyo tunaona angani vinaitwa vitu vya mbinguni. Miili hiyo ya angani inayotoa joto na nuru yake mwenyewe huitwa nyota. Nyota zinaonekana kusonga kutoka mashariki hadi magharibi kwa sababu ya kuzunguka kwa dunia kutoka magharibi hadi mashariki. Miili hiyo ya angani inaonekana waziwazi kwa kutumia kifaa kinachoitwa darubini-upeo. Tawi la sayansi ambalo tunasoma juu ya miili mbalimbali ya angani huitwa elimu ya nyota. Hakuna ajuaye ukubwa wa ulimwengu. Kulingana na utafiti wa kisayansi ulimwengu unaongezeka kwa ukawaida. Katika majiji makubwa kutazama nyota kwaweza kupunguzwa kwa sababu ya taa nyangavu, moshi na vumbi. Makundi ya nyota bilioni huitwa galaksi. Milky Way (Akasha Ganga) ni galaksi ya spiral ambayo inaonekana kama bendi nyeupe katika anga. Jua, dunia, sayari nyingine za mfumo wa jua na nyota nyingi ni sehemu ya njia ya maziwa. Jinsi ya kupima umbali katika ulimwengu? Umbali kati ya nyota na sayari ni mkubwa sana hivi kwamba hauwezi kupimwa kwa kilometa. Tunatumia kipimo cha umbali cha angani kinachoitwa mwaka-nuru. Kasi ya mwanga ni 3x108m s. Mwaka wa nuru ni umbali ambao mwanga husafiri kwa mwaka mmoja. 1 light-years = 3 x 108 x 365 x 24 x 60 x 60 s = 9.5 x 1012 km (parsec) ni kipimo cha umbali wa nyota inayotumiwa kupima umbali mkubwa kati ya vitu vya angani nje ya mfumo wa jua. 1 parsec = 3.26 light year: Nyota iliyo karibu zaidi na dunia ni jua. Umbali kati ya dunia na jua ni 15 x 107 km. Nuru ya jua inachukua sekunde 500 au dakika 8 na sekunde 20 kufikia dunia. Nyota ya pili iliyo karibu zaidi na dunia baada ya jua ni <unk>Proxima Centauri<unk>. Ina umbali wa miaka 4.2 ya mwanga. Nuru inayotokana na nyota hii ina umri wa miaka 4.2. Mwezi- Mwili wa angani ambao huzunguka sayari huitwa mwezi au setilaiti ya asili. Kuna idadi tofauti ya miezi kwa sayari tofauti za mfumo wa jua. Dunia ina mwezi mmoja tu. Inazunguka dunia kwa muda wa siku 27.3. Pia huzunguka mhimili wake katika kipindi hichohicho cha wakati. Mwezi wa Mwezi (Fig-Phases of Moon) (Source-http: www.astronomy.ohio-state.edu) Mfumo wa jua na sayari-Jua ni nyota ya ukubwa wa kati iliyo karibu zaidi na sayari ya dunia. Inafanyizwa na gesi kama hidrojeni na heliamu. Mmenyuko wa nyuklia katika jua ndiyo kisababishi cha joto linalotokezwa na jua. Joto la kiini ni milioni 14. Kwa upande wa juu, joto ni digrii 6400 Celsius. Kipenyo cha jua ni karibu kilomita milioni 1.4. Ni mara 110 zaidi ya dunia. Jua ndilo chanzo kikuu cha nishati duniani. Kuna sayari nane katika mfumo wa jua. Sayari na miezi yake hufanyiza mfumo wa jua. "Pluto" ilikuwa ndogo sana isiweze kuitwa sayari. Kwa hiyo, iliondolewa kwenye orodha ya sayari za mfumo wa jua mwaka 2006. Vitu hivyo vya angani vinavyozunguka jua huitwa sayari. Hawana nuru yao wenyewe na huonyesha nuru ya jua. Kwa sababu ya kuwa karibu na dunia, mwanga wao unaorudiwa haupunguzi sana na haung'aa. Ni ndogo kuliko nyota. Zimetengenezwa na miamba na gesi. Wakati unaotumiwa na sayari kukamilisha mzunguko mmoja huitwa "kipindi cha mzunguko". Sayari huzunguka kwenye mhimili wao wenyewe pia pamoja na mzunguko kuzunguka jua. Wakati kuchukuliwa kukamilisha mzunguko mmoja juu ya mhimili wake inaitwa "kipindi cha mzunguko". Sayari huzunguka jua katika njia fulani inayoitwa "orbit". Sayari nne zilizo karibu na jua huitwa sayari za ndani. e.g.- Mercury, Venus, Dunia na Mars. Sayari nne zilizo mbali sana na jua huitwa sayari za nje. e.g.- Jupita, Saturn, Uranus na Neptune. 1. Uwe na mtazamo wa kweli Mercury (Budh) - Ni sayari iliyo karibu zaidi na jua. Ni sayari ndogo zaidi katika mfumo wa jua. Ni vigumu kuiona wakati wa mchana kwa sababu ya mwangaza mkali wa jua. Inaweza kuonekana kabla tu ya jua kuchomoza na baada ya jua kutua karibu na upeo wa macho. Mercury haina sayari ya asili. Mvuto wake ni mdogo kwa hiyo hauwezi kushikilia angahewa. Hakuna angahewa kwenye zebaki. Kwa hivyo, joto linatofautiana kati ya -200 ° C hadi 400 ° C. 2. Uwezekano wa kupata Venus (Shukra) - Ni sayari iliyo karibu zaidi na dunia na karibu na ukubwa sawa na dunia. Kuna angahewa kwenye Venus yenye gesi ya kaboni dioksidi. Kwa hivyo, joto la joto linaongezeka hadi 480 ° C. Inaonyesha sehemu kubwa ya nuru ya jua. Kwa hiyo, ni nyota yenye kung'aa zaidi katika mfumo wa jua. Inaweza kuonekana kabla ya jua kuchomoza na baada ya jua kutua. Pia huitwa "nyota ya asubuhi" (kwa siku 292 katika upeo wa mashariki) na "nyota ya jioni" (kwa siku 292 katika upeo wa magharibi) ingawa ni sayari. Tofauti na sayari nyingine, sayari ya Venus huzunguka juu ya mhimili wake kutoka mashariki hadi magharibi. 3. Uwe na mtazamo wa kweli Dunia (Prithvi) - Dunia ni sayari yenye joto la wastani ambapo uhai upo. Uwepo wa gesi kama vile oksijeni na kaboni dioksidi ulisaidia katika chanzo na kuwepo kwa uhai duniani. Kuna maji na ozoni katika anga ambayo huondoa miale ya UV inayokuja duniani kutoka jua. Inaonekana kuwa na rangi ya bluu-kijani-kibichi ukiwa angani. Dunia inazunguka mhimili wa kuwaziwa ambao umepindika kwa pembe ya nyuzi 23 na nusu. Ikweta hugawanya dunia katika pembe mbili za dunia - pembe ya kaskazini na ya kusini. Wakati hemisphere ya kaskazini inaelekea kuelekea jua basi kuna msimu wa majira ya joto katika hemisphere ya kaskazini na majira ya baridi katika hemisphere ya kusini. Kwa mfano, wakati dunia ya kusini inapopelekea upande wa jua, kuna majira ya kiangazi katika dunia ya kusini na majira ya baridi kali katika dunia ya kaskazini. Tarehe 21 Machi, muda wa mchana na usiku ni sawa. Pia huitwa "Vernal equinox" au "March equinox". Wakati huo, kutakuwa na msimu wa masika katika kizio cha kaskazini huku msimu wa vuli ukiwa katika kizio cha kusini. Baada ya hapo, siku huanza kuwa ndefu na usiku huanza kuwa mfupi katika kizio cha kaskazini. Inaendelea hadi Juni 21 au <unk>Summer solstice<unk>. Litawa siku ndefu zaidi ya mwaka. Baada ya hapo, siku huanza kufupika na usiku huanza kuwa mrefu katika kizio cha kaskazini. Septemba 23 - urefu wa mchana na usiku huwa sawa. Pia huitwa "Autumnal equinox" au "September equinox". Wakati huo kutakuwa na majira ya vuli katika nusu-duniani ya kaskazini na majira ya kuchipua katika nusu-duniani ya kusini. Baada ya hapo, siku huanza kufupika na usiku huanza kuwa mrefu katika kizio cha kaskazini. Inaendelea hadi Desemba 22 au <unk>Winter solstice<unk>. Litawa siku fupi zaidi ya mwaka. Baada ya hapo, siku huanza kufupika na usiku huanza kuwa mrefu katika kizio cha kaskazini. Siku mbili kwa mwaka, Machi 21 na Septemba 23, jua huinuka katika upande wa mashariki. Siku nyingine zote, jua huchomoza kaskazini mwa mashariki au kusini mwa mashariki. "Jina ""solstice"" linamaanisha ""mwisho wa mwaka"" au ""mwisho wa mwaka"" isipokuwa ikweta." 4. Uwe na uhakika Mars (Mangal) - Ni karibu nusu ya ukubwa wa dunia na inaitwa pia sayari nyekundu. Ni anga nyembamba sana ina hasa gesi ya kaboni dioksidi na mvuke wa maji. Joto la joto la joto la joto la joto la joto la joto la joto la joto la joto la joto la joto la joto la joto la joto la joto la joto la joto la joto la joto la joto la joto. Ina uso wenye miamba ya waumbaji na milima. Volkano kubwa zaidi na bonde refu zaidi zinapatikana kwenye sayari ya Mars. Kuna miezi miwili ya sayari ya Mars. 5. Uwe na mtazamo mzuri. Jupita (Brihaspati) - Ni sayari kubwa zaidi ya mfumo wa jua. Kiasi chake ni mara 1300 ya dunia na uzito wake ni mara 318 ya dunia. Mduara wake ni mara kumi na moja ya ule wa dunia. Ina dhoruba kubwa inayozunguka inayoitwa "Great Red Spot". Jupita huzunguka (kuzunguka) juu ya mhimili wake haraka kuliko sayari nyingine yoyote. Jupita ina satelaiti 72 za asili. 6. Uwe na uhakika Saturn (Shani) - Ni sayari ya pili kwa ukubwa katika mfumo wa jua. Ina pete tatu maridadi zilizofanyizwa na barafu na vumbi. Uso wake umefanyizwa na umajimaji na gesi. Ina miezi 53. Mfano: Titan, Hyperion, Phoebe na kadhalika. 7. Uwe na mtazamo gani? Uranus (Indra) <unk> Ni alifanya juu ya hidrojeni, heliamu na methane kama gesi. Inaonekana kuwa ya rangi ya bluu-kijani kwa sababu ya joto la chini sana ambalo huchanganya gesi ya metani. Kama vile Venus, pia huzunguka kutoka mashariki hadi magharibi. Ni sayari ya tatu kwa ukubwa. Ina miezi 27. 8. Uwe na mtazamo gani? Neptune (Varun) - Ni sayari ya nne kwa ukubwa wa mfumo wa jua. Anga lake lina hidrojeni, heliamu na metani. Inaonekana rangi ya bluu kwa sababu mwanga mwekundu huchukuliwa na methane na mwanga wa bluu ni hasa kutawanyika. Pia inaitwa kama <unk>Blue Giant<unk>. Kipenyo chake ni karibu mara nne ya kipenyo cha dunia. Ina miezi 14. Mkusanyiko wa nyota - Kikundi cha nyota zilizo na umbo au muundo unaotambuliwa huitwa mkusanyiko wa nyota. Watu wa kale walianza kutambua maumbo ya makundi ya nyota. Maumbo ya makundi ya nyota yanafanana na vitu vilivyojulikana na watu wa kale kama vile wanyama na wahusika wa hekaya. Kuna makundi ya nyota 88 yanayojulikana. e. g.-Great Bear, Orion, Cassiopeia, Leo kubwa, Capricorn nk. 1. Uwe na mtazamo wa kweli Ursa Major, Big Dipper, Great Bear, Sapphire, na Seven Sages ni nyota saba za kawaida katika kundi hili la nyota. Umbo lake ni kama chungu kikubwa au alama ya swali. Kuna nyota nne katika bakuli na nyota tatu katika chungu. Inaweza kuonekana katika anga la kaskazini wakati wa majira ya kiangazi katika usiku ulio wazi bila mwezi. Katika mwelekeo wa kaskazini kwa nyota mbili za mwisho za bakuli, kuna nyota mkali inayoitwa nyota ya pole (Dhruvtara). Ni mara tano zaidi ya umbali kati ya nyota mbili za bowl. Kwa sababu ya mzunguko wa dunia, Ursa Major huonekana kuzunguka nyota ya polepole kutoka mashariki hadi magharibi. 2. Uwezekano wa kupata Orion/Hunter-Hii ni kundi la nyota lenye kupendeza sana katika anga la kusini. Inaweza kuonekana wakati wa majira ya baridi kali mwishoni mwa jioni. Ina nyota 7-8 zenye kung'aa. Nyota tatu za katikati zinawakilisha mshipi wa mwindaji. Nyota nyingine nne zenye kung'aa hufanyiza umbo la pembetatu. Katika upande wa mashariki wa ukanda wa Orion, kuna nyota nyangavu iitwayo Sirius. 3. Uwe na mtazamo wa kweli Cassiopeia <unk> Ni kundi la nyota maarufu katika anga la kaskazini. Inaonekana wakati wa majira ya baridi kali mwishoni mwa jioni. Umbo lake ni kama ‘W au ‘M iliyopotoka. Satelaiti bandia-Ziko vitu vilivyotengenezwa na wanadamu ambavyo huzunguka dunia karibu zaidi na mwezi. Kasi ya mzunguko wa satelaiti bandia ni sawa na kasi ya mzunguko wa dunia. Satelaiti hizo hutumiwa kwa ajili ya mawasiliano ya simu, utangazaji wa redio na televisheni, utabiri wa hali ya hewa, utafiti wa baharini, ulinzi, elimu na kadhalika. Kwa mfano - Aryabhat, EDUSAT, Kalpana-1, IRS, INSAT nk. Q1: Ni nini kati ya vitu vifuatavyo ambavyo haviko katika mfumo wa jua? (a) Asteroid (b) Satellite (c) Constellation (d) Comet (c) Constellation (q) (c) (d) (c) (c) (d) (c) (c) (d) (d) (e) (e) (e) (e) (e) (e) (e) (e) (e) (e) (e) (e) (e) (e) (e) (e) (e) (e) (e) (e) (e) (e) (e) (e) (e) (e) (e) (e) (e) (e) (e) (e) (e) (e) (e) (e) (e) (e) (e) (e) (e) (e) (e) (e) (e) (e) (e) (e) (e) (e) (e) (e) (e) (e) (e) (e) (e) (e) (e) (e) (e) (e) (e) (e) (e) (e) Sirius, Mercury, Saturn, na Earth ni sehemu ya mwezi ambayo inaonyesha mwangaza wake. (b) umbali wetu kutoka mwezi unaendelea kubadilika. (c) kivuli cha Dunia hufunika sehemu tu ya uso wa mwezi. (d) unene wa angahewa la mwezi si wa mara kwa mara. Jibu- (a) tunaweza kuona sehemu tu ya mwezi ambayo inaonyesha mwanga kuelekea kwetu. "Kama ilivyoelezwa hapo juu, ""nyota"" ni ""nyota"" ambayo ni ""nyota"" ya ""nyota"" ya ""nyota"" ya ""nyota"" ya ""nyota"" ya ""nyota"" ya ""nyota"" ya ""nyota"" ya ""nyota"" ya ""nyota"" ya ""nyota"" ya ""nyota"" ya ""nyota"" ya ""nyota"" ya ""nyota"" ya ""nyota"" ya ""nyota"" ya ""nyota"" ya ""nyota"" ya ""nyota"" ya ""nyota"" ya ""nyota"" ya ""nyota"" ya ""nyota"" ya ""nyota"" ya ""nyota"" ya ""nyota"" ya ""nyota"" ya ""nyota"" ya ""nyota"" ya ""nyota"" ya ""nyota"" ya ""nyota"" ya ""nyota"" ya ""nyota"" ya ""nyota"" ya ""nyota"" ya ""nyota"" ya ""nyota"" ya ""nyota"" ya ""nyota"" ya"" ya ""nyota"" ya"" ya ""nyota"" ya"" ya ""nyota"" ya"" ya"" ya"" ya"""""""" (d) Mwili wa angani unaozunguka sayari unajulikana kama...................... (e) Nyota zinazopiga haziko kweli................ (f) Asteroids hupatikana kati ya mizunguko ya................ "Mungu (Neptune) na ""Mars"" (Mars) ni nyota za asili za sayari ya Mars, na ""Pole Star"" ni nyota ya jua." Mercury ni sayari ndogo zaidi katika mfumo wa jua. Uranus ni sayari iliyo mbali zaidi katika mfumo wa jua. (a) INSAT ni satelaiti ya bandia. (e) Kuna sayari tisa katika mfumo wa jua. (f) Nyota ya Orion inaweza kuonekana tu kwa darubini-upeo. ( Jibu. (a) (b) (c) (d) (e) (f) (f) (f) (g) (g) (g) (g) (g) (g) (g) (g) (g) (g) (g) (g) (g) (g) (g) (g) (g) (g) (g) (g) (g) (g) (g) (g) (g) (g) (g) (g) (g) (g) (g) (g) (g) (g) (g) (g) (g) (g) (g) (g) (g) (g) (g) (g) (g) (g) (g) (g) (g) (g) (g) (g) (g) (g) (g) (g) (g) (g) (g) (g) (g) (g) (g) (g) (g) (g) (g) (g) (g) (g) (g) (g) (g) (g) (g) (g) (g) ( Jibu- Inaonekana kama nyota ya jioni katika anga la magharibi tu baada ya machweo. Q: Ni sayari gani kubwa zaidi katika mfumo wetu wa jua? Q: Ni nini constellation? Taja nyota mbili zozote. Jua: Kundi la nyota ni kikundi cha nyota ambazo hufanya umbo la kuwaziwa angani usiku. Mstari wa kwanza ni Ursa Major na Orion, na wa pili ni Mstari wa Pili, ambao unaonyesha nafasi za nyota katika Mstari wa Pili na Orion. Mwezi na Asteroids: Jinsi ya kujua nyota ya polar kwa msaada wa Ursa Major Jibu: Kwanza kabisa mtu anapaswa kupata Ursa Major katika anga la kaskazini wakati wa msimu wa kiangazi katika usiku wazi bila mwezi. Kuna nyota nne katika bakuli na nyota tatu katika chungu. Katika mwelekeo wa kaskazini kwa nyota mbili za mwisho za bakuli, kuna nyota mkali inayoitwa nyota ya pole (Dhruvtara). Ni umbali wa mara tano kati ya nyota mbili za Ursa Major. Inaonekana kwamba Ursa Major inazunguka Nyota ya Pole. Swali: Je, nyota zote angani zinaenda? Eleza jambo hilo. Jibu- La, Nyota ya Pole haionekani kusonga. Ni kwa sababu Nyota ya Ncha iko karibu na mwelekeo wa mhimili wa mzunguko wa dunia. Kwa hiyo, inaonekana imesimama. Kwa nini umbali kati ya nyota huonyeshwa katika miaka ya mwanga? "Kama unavyoelewa, ""Nyota"" ni nyota iliyo umbali wa miaka nane ya mwanga kutoka duniani." Jibu: Umbali kati ya nyota ni mkubwa sana. Ni vigumu kueleza umbali mkubwa kama huo katika kilometa (km. Kwa hiyo, mwaka wa nuru hutumiwa kupima umbali kati ya vitu vya angani. Nyota iko umbali wa miaka nane ya mwanga kutoka duniani, na kwa hivyo, umbali kati ya nyota na dunia ni miaka nane ya mwanga. Umbali kati ya dunia na nyota hiyo ni 8 x 9.5 x 1012 km = 7.6 x 1013 km. Radius ya sayari ya Jupiter ni mara 11 ya radius ya dunia. Hesabu uwiano wa kiasi cha sayari ya Jupita na Dunia. Jupita inaweza kutoshea Dunia ngapi? Kwa mfano, radius ya dunia ni r = 11 r, radius ya dunia ni r = 4 r, radius ya dunia ni r = 4 r, radius ya dunia ni r = 4 r, radius ya dunia ni r = 11 r, radius ya dunia ni r = 11 r, radius ya dunia ni r = 11 r, radius ya dunia ni r = 11 r, radius ya dunia ni r = 4 r, radius ya dunia ni r. Je, mchoro huo ni sahihi? Ikiwa sivyo, suluhisha. Jibu- Hapana, mchoro katika swali si sahihi. Msimamo wa Mars, Venus, Uranus na Neptune si sahihi. Msimamo wa sayari ndogo-ndogo pia si sahihi. Sketch sahihi ni kama kama- VKSCIENCE kwenye YouTube