4.1 To investigate the properties of the sun and to explain concepts

Natural sciences

Planet earth and the universe

Our own star – the sun

Educator section

Memorandum

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

Content

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.

CONSTELLATIONS

• 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.

TASK 3

• 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

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CRITERIA FOR ASSESSING PARAGRAPHS

Assessment

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.