PPSC past papers

MILKY WAY GALAXY THE UNIVERSE MILKY WAY GALAXY FORMATION OF EARTH  We've learn about how star and galaxies form, and there are hundreds of billions of in the observable universe, each with many millions or billions of individual stars.  So which galaxy is our home? Let's take a look at this collection of galaxies. First thing is called the Virgo supercluster, containing over a 100 groups and cluster of galaxies, such as the virgo cluster, and the local group. Now let's zoom in on the local group. This contain more than 50 galaxies, many of which are tiny dwarf galaxies, but some of which are fairly large, by galactic standard. The largest of these is called the Andromeda Galaxy, which is a spiral galaxy. MILKY WAY GALAXY Around half that size, the next biggest is called the milky way galaxy, also ask spiral Galaxy, and that's our home. It's a pretty typical barred spiral galaxy, containing somewhere between 200 billion and 400 billion stars. It is about 10, 0000 lig

HUBBLE TELESCOPE THE UNIVERSE HUBBLE TELESCOPE  Hubble is an upgradable space telescope orbiting at almost 600 kilometre placing it well above most of our image distracting atmosphere. It takes about 97 minutes to complete each orbit. It is designed to take high resolution images and accurate spectra by concentrating start light to form sharper image than are possible from the ground.  Where the atmospheric twinkling of the stars limits, the clarity to gather as much light as possible from the faint objects. It observes any telescope needs the largest mirror, it can get, despite hubble's relatively modest mirror diameter of 2.4 metres. Its well able to complete with ground based telescope having mirror that are 10 or 20 times larger in collecting area.  HUBBLE TELESCOPE PHOTO Hubble is a large satellite above 16 metres long or the size of a small bus. It's also one of the most complicated pieces of technology ever built. It contains over 3000 sensors that continuously monitor t

EUROPA MOON OF JUPITER EUROPA THE FLOATING OCEAN IN THE SPACE  It used to be thought that the chance of meeting alien life on the planet beyond Mars, dropped close to absolute zero, much like the temperature, but that we before we knew where to look.  When life on Jupiter was first seriously discussed in the seventies, there was only one place worth considering the clouds. Perhaps a whole community of aliens could live drifting above in a Goldilocks zone. Where it's warm wet and Sunny Much like plankton floating in the sunlit oceans of the earth.  OCEANS IN EUROPA   Always a long shot the prob killed the idea when it found no evidence of complex organic molecules in the atmosphere. But when Galileo took closer look Europa, the picture changed.  Europa is a fascinating object, if you imagine descending onto a world that looks very place like The Frozen wastes of the Arctic or the Antarctic you get a pretty good impression of what's going on it's very very bright because ice

  TRITON THE MOON OF NEPTUNE TRITON MOON HISTORY Beyond the warmth of the sun past, the four Rocky planets further than the gas giants at the very distance age of our solar system like two worlds that we are only just beginning to explore and understand. They are the ice giants Uranus and Neptune. These planets are dozens of times the mass of the Earth. And they are found so distant that we have only managed to visit them once, in 1977 the Voyager 2 spacecraft took to the skies embarking on a 12 year mission to reach. What was once considered unreachable, but we learn more about these massive icy worlds, we learn more about the satellites that orbit them to the iciest the most far out moons in the solar system.  In the Neptunian system one moon stands out from the rest Triton. Triton is a special moon with properties we never imagined objects so far from the sun possessing but it was not until we reached the moon in 1989 that we finally begin to understand its true origins. Triton capt

THE EARTH PLANET THE UNIVERSE THE EARTH THE LIFE  Earth, the only planet known to maintain life. A product of scientific phenomena and sheer chance. This blue speck in the space holds the past, present, and future of our very existence.  THE EARTH BLUE PLANET Approximately 4.5 billion years ago, the earth formed from particle left over from the creation of sun. Gravity drew particles together to form pebbles which then formed boulders, and eventually, the earth.  As its heart is a solid inner core powered by liquid outer core. Above this sits the mantle, made of following silicate rocks, and Rocky crust. This Rocky mass is the third planet from the sun, orbiting the star from an average distance of about 93 millions miles. It's close enough to the sun to be warm unlike the cold gas giants.  But not so close that its surface is exposed to extreme heat and solar radiation as is the case with Mercury. Bharat unique position in the solar system allows it to house phenomena yet to be fo

 FORMATION OF EARTH AND MOON  HISTORY OF EARTH The formation of the Earth is related to the formation of the solar system. The gases that form the solar system gradually started shirking increasingly more matter gathered in the centre while temperature was constantly increasing. The sun formed from this condensed molecular cloud of dust. Due to rapid rotation the rest of the clouds scattered and flattened into an aur orbiting protoplanetary disc around the sun. The dust particle in the protoplanetary disc collided and stuck together due to electrostatic attraction forming planetesimals. When there is a size about one kilometre they collided due to mutual gravity forming proto planets which were a few thousand kilometres in diameter.  THE EARTH PLANET This is how the Earth was formed 4.6 billion ago. Around a hundred and seventy million years after the formation of Earth a similarly young planet known as Thea Struck the Earth's still soft crust. Thea was demolished after the collisi

 ANDROMEDA GALAXY HOW FAR OUR SOLAR SYSTEM? INTRODUCTION OF LIGHT YEAR The speed of light is over 299 million metres per second or over 20099000 kilometers per second. Speed of light is as well the fastest achievable speed in the universe or not really achieve able in order to go at the speed of light. You would have to have no no mass for no material that you are made of meaning in order to go at the speed of light. You cannot exist physically but we can get very close to the speed of light. The light speed may seem like much but taking into consideration interstellar distance. it is not that impressive and does not match our human ambitions to reach others star fast. Light can in 1 second go around ears 7.5 times but since light has its limit even when you are talking to are human 1 metre away. You would see him 3.3 nanoseconds. In the past or billionth of a second in the past. Everything you see around you is how it was not how it is now you can never see anything in the universe as

PROXIMA CENTAURI THE UNIVERSE NEAR PLANET TO OUR SOLAR SYSTEM Since the dawn of space age, in the middle of 20th century, we have sent unnamed probes all over the solar system, which have given us some incredible image of the planet and moon that are part of our solar system. There are plans to send humans to Mars, the galilean moons of Jupiter should not be too long after that. But as existing as it will be to colonies our system, beyond and Mars there are only a handful of moon that are even remotely fit for such endeavor.  Power search for habitable worlds will inevitably leads us outside of our own system. This poses tremendous challenge, because as far away as the other planets and moons in this system are, this distance is utterly insignificant compared to vast distances to other stars. We will certainly need to innovate new methods of probe propulsion in order to get there in a reasonable amount of time.  PROXIMA CENTAURI EARTH LIKE PLANET   But we will achieve this, and what we

 THE MARS PLANET THE UNIVERSE HISTORY OF MARS PLANET The red planet of our mysterious celestial neighbour. Every day we learn more and more about Mars planet as the race to unlock its secret ramps up does it just look like cold dry dead planet, but the more we study it the more we learn that it's actually dynamic alive. But for every answer we discover a million more questions arise so what doing know.  SURFACE OF MARS PLANET Mass is one of the most interesting planet of the solar system. It is the fourth planet from the sun it is Rocky cold desert world. Mars has very thin atmosphere. On March we see volcanoes canyon and impact basins like the ones we see on earth . Many of the same physical Land features we see on earth also exist on Mars. It is the most widely searched planet for life. One day Mars is completed with in 24.6 while a whole trip around the sun is completed with in 669.6 days. So mass is pretty much similar to earth. It is only planet apart from earth that lies with

 VOYAGER 1 AIRCRAFT THE UNIVERSE  VOYAGER 1  In September 1977 in our NASA Voyager 1 spacecraft begin its long its long journey into the unknown when it was launched the Kennedy space centre 16 days later than Voyager 2, launch. These probes main object was to conduct close up studies of the outer planets including their large moons and mysterious rings system. Voyager 1 was launched on a faster more direct path that would send the spacecraft hurtling towards Jupiter and Saturn. Voyager 2 would take a slightly different path that would also take it past the two gas giants but then on to Uranus and Neptune taking advantage of rear planetary arrangements that only occurs once every 175 years.  With in the couples of year after its journey Voyager 1 sent back its first image won a which reveals a crescent shaped Earth and moon hanging in darkness.  SPACECRAFT   Because of the direct path that Voyager 1 was set on it only took the spacecraft approximately one and a half year to get to firs

 THE NEPTUNE PLANET THE UNIVERSE NEPTUNE PLANET Look up into a clear night sky with your naked eye and what planets would you see?  Technically you would be able to see all of them at one time or another all of them A apart from Neptune. It is the smallest of gas giant and also the furthest away. And it is a perplexing place. You would think our planet so far from the sun would not have a dynamic atmosphere that exhibit great storms and superfast Winds.  PHOTO OF NEPTUNE PLANET So why is this planet as interesting as it is?  Neptune is the only planet found through mathematical prediction. You see when Uranus was discovered and astronomers  verb plotting its orbit, they noticed that Uranus was not following their models. From perturbed orbit of Uranus, the scientist in 1846 concluded that there must be another undiscovered planet and he predicted where it should be, and remarkably Jahan gall was able to find it only a degree away from the predicted point.  Triton neptune's biggest

 IS PLUTO IS THE PLANET? THE UNIVERSE  HISTORY OF PLANETS DISCOVERY  Throughout the ages, the number of planets in our solar system has gone up and down. No, this is not because planets have suddenly appeared and disappeared, but rather due to how they world discovered. Science antiquity, they were 5 planets beyond Earth, which are the ones visible to naked eye, mercury Venus Mars Jupiter and Saturn. The ancient Greek at did the sun and moon to their list of planets, but that idea never really caught on. In the late 1700s, Uranus was discovered, which was revolutionary at the time as no one considered there could be more planet bye on the visible five. After the discovery more and more planets candidates being found, like Ceres, vesta, palas and Juno, which are all found in what we know as the asteroid belt for the large asteroids between the orbit of Mars and Jupiter.  In science textbooks in the early 1800s, devar all listed as planets. In the middle of 1800s, netzone was also discov

 THE JUPITER PLANET THE UNIVERSE  ALL ABOUT THE THE PLANET JUPITER Jupiter is a biggest planet in fact it's quite larger than every other planet in solar system. Jupiter comes in with a radius of 43000 441 miles for 69000  kilometre which which is almost 10,000 miles or 16000 kilometres larger than the next largest planet Saturn in comparison our lovely little planet it would take 11.2 Earth side-by-side to match the diameter of Jupiter it's believed that jupiter's massive size is responsible for directing the path of small objects with the solar system either standing comets or asteroid into or away from the inner solar system.                                     THE PLANET JUPITER  Jupiter five times for other if you look at a map of the solar system you will find the mercury Venus Earth and Mars are relatively close to one another and or with in 115 million miles 249 million kilometres from the sun then Jupiter which just had to be completely different and separate itsel

SOLAR SYSTEM THE UNIVERSE   Have you look up and see the secret of the sky and ? Higher than the birds, past the clouds, and further than the moon a whole host of fascinating objects in outer space.                                SOLAR SYSTEM AND PLANETS Let's imagine for a moment and leave the earth, sit on the space craft and look out of the space. We see the solar system and power of the sun where all eight planets are orbiting the sun , and solar means something to do with the sun.                          THE MASSIVE SUN   The sun is a star , just like many of the star that you can see in the sky just many times closer to us. Still, the sun is very very for away from Earth; almost 93 millions miles away: that's way it looks so small, even though it's the biggest object in the solar system. Infact the sun makes up more than 99% of the mass in the solar system. If you put all the planets, moons, asteroids, comets and everything else in the solar system together , they wo