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Natural sciences

Planet earth and the universe

Our own star – the sun

Educator section


Assignment 3:

Hubble space telescope : This is an instrument which allows astronomers to more of the universe than can be seen with the naked eye. The Hubble Space Telescope is the largest telescope in space. It was launched in 1990 by the USA.

Satellites : We make a distinction between natural satellites and man-made satellites. Natural satellites are celestial bodies that orbit around other celestial bodies. Planets are satellites of the sun. Artificial or man-made satellites are instruments designed to send information to the earth. These satellites are put in an orbit around the earth. Satellites take fixed times to complete their orbits.

Robot Exploration Vehicles ; Robot vehicles are unmanned spacecraft. They can be used to explore the moon and the planets. Some orbit planets to explore them, but don’t land on them.

Leaner section


Activity: to investigate the properties of the sun and to explain concepts such as “constellations” and the “exploration of space” [lo 1.2]

  • The sun is an ordinary star in the Milky Way (our galaxy). It is an incredibly large revolving ball of gas with a diameter of 1,4 million kilometres. This is more than a hundred times more than the earth’s diameter. The sun is 150 million kilometres from the earth and it takes 8 minutes for the light from the sun’s surface to reach the earth.
  • The sun develops so much energy that its surface glows white-hot at a temperature of 6 000 degrees Celsius. The energy originates at the centre of the sun as a result of nuclear activity. The sun has been shining for about 4,5 milliard years. After another 5 milliard years the sun’s supply of hydrogen will be exhausted. No life can exist on Earth without sunlight.
  • The sun is vital for life on Earth. It supplies almost all the energy that we have to our disposal. Even the coal that we burn originally was forests of which the growth was sustained by the energy from the sun. No life on Earth will survive if the sun stops shining.
  • The universe is so big that astronomers measure it in light-years. A light-year is the distance that light travels in one year – 9,5 million kilometres. Light moves at 300 000 kilometres a second.


  • Astronomers have divided the universe into constellations. The first astronomer to investigate the Southern Cross from South Africa was Guy Tachard in 1685. This constellation appears on the flags of New Zealand and Australia.

  • The three stars of Orion’s Belt lie in a straight line. It is probably the constellation which is most easy to recognize in the Southern Hemisphere. Orion is named after a hunter of Greek mythology. Some of the stars form his belt.


  • The telescope is an instrument which astronomers use. Large telescopes are housed in special buildings called observatories. The exploration of space would not have been possible without telescopes, satellites and unmanned spacecraft.

Write a short paragraph (6 -10 lines) on each of the following unmanned spacecrafts:

  • Hubble space telescope
  • Satellite
  • Robot exploratory craft












Level 4 Level 3 Level 2 Level 1
Planning and coherence of structure: thorough planning, logical and effective planning sufficient, correct sentence structure little evidence of planning, faulty sentence construction no evidence of planning, many errors in sentence construction
Correctness of information: information correct, very interesting, shows creativity information correctly given information not entirely accurate information is full of factual errors
Presentation: extremely neat, orderly and creative presentation is neat and orderly presentation slightly confused and untidy presentation not at all structured, untidy


Learning Outcome 1: The learner will be able to act confidently on curiosity about natural phenomena, and to investigate relationships and solve problems in scientific, technological and environmental contexts.

Assessment Standard 1.2: We know this when the learner conducts investigations and collects data: organises and uses apparatus/equipment or sources to gain and record information.

Questions & Answers

how do you translate this in Algebraic Expressions
linda Reply
why surface tension is zero at critical temperature
Need to simplify the expresin. 3/7 (x+y)-1/7 (x-1)=
Crystal Reply
. After 3 months on a diet, Lisa had lost 12% of her original weight. She lost 21 pounds. What was Lisa's original weight?
Chris Reply
what is biological synthesis of nanoparticles
Sanket Reply
what's the easiest and fastest way to the synthesize AgNP?
Damian Reply
types of nano material
abeetha Reply
I start with an easy one. carbon nanotubes woven into a long filament like a string
many many of nanotubes
what is the k.e before it land
what is the function of carbon nanotubes?
I'm interested in nanotube
what is nanomaterials​ and their applications of sensors.
Ramkumar Reply
what is nano technology
Sravani Reply
what is system testing?
preparation of nanomaterial
Victor Reply
Yes, Nanotechnology has a very fast field of applications and their is always something new to do with it...
Himanshu Reply
good afternoon madam
what is system testing
what is the application of nanotechnology?
In this morden time nanotechnology used in many field . 1-Electronics-manufacturad IC ,RAM,MRAM,solar panel etc 2-Helth and Medical-Nanomedicine,Drug Dilivery for cancer treatment etc 3- Atomobile -MEMS, Coating on car etc. and may other field for details you can check at Google
anybody can imagine what will be happen after 100 years from now in nano tech world
after 100 year this will be not nanotechnology maybe this technology name will be change . maybe aftet 100 year . we work on electron lable practically about its properties and behaviour by the different instruments
name doesn't matter , whatever it will be change... I'm taking about effect on circumstances of the microscopic world
how hard could it be to apply nanotechnology against viral infections such HIV or Ebola?
silver nanoparticles could handle the job?
not now but maybe in future only AgNP maybe any other nanomaterials
I'm interested in Nanotube
this technology will not going on for the long time , so I'm thinking about femtotechnology 10^-15
can nanotechnology change the direction of the face of the world
Prasenjit Reply
At high concentrations (>0.01 M), the relation between absorptivity coefficient and absorbance is no longer linear. This is due to the electrostatic interactions between the quantum dots in close proximity. If the concentration of the solution is high, another effect that is seen is the scattering of light from the large number of quantum dots. This assumption only works at low concentrations of the analyte. Presence of stray light.
Ali Reply
the Beer law works very well for dilute solutions but fails for very high concentrations. why?
bamidele Reply
how did you get the value of 2000N.What calculations are needed to arrive at it
Smarajit Reply
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Source:  OpenStax, Natural sciences grade 7. OpenStax CNX. Sep 16, 2009 Download for free at http://cnx.org/content/col11077/1.1
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