PPSC past papers

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