Transcript Space Part2
Orbit height and speed Imagine the mountain in Newton’s thought experiment was lower. If the same amount of gunpowder was used, would a ball shot from the lower mountain travel the same distance as from the high mountain? No. More gunpowder would be needed to make the ball travel the same distance. Therefore, more gunpowder would be needed to make the ball go into orbit. This means that if a satellite orbits the Earth at a lower altitude, it needs to travel faster to stay in orbit. 1 of 48 © Boardworks Ltd 2008 Satellite orbits 2 of 48 © Boardworks Ltd 2008 Which type of satellite? 3 of 48 © Boardworks Ltd 2008 What is the Hubble Space Telescope? The Hubble Space Telescope (HST) is a satellite in orbit around the Earth. It was deployed from the Space Shuttle Discovery on 24 April 1990. The HST is outside the Earth’s atmosphere and does not experience the same interference as Earth-based telescopes. This means that its images of the Universe are much more detailed than images observed from Earth. 4 of 48 © Boardworks Ltd 2008 Questions about satellites 5 of 48 © Boardworks Ltd 2008 Relative size of the Universe 6 of 48 © Boardworks Ltd 2008 Is Pluto a planet? In 2006, the International Astronomical Union defined a planet as: “a celestial object that orbits the Sun, has enough mass to be spherical, and has cleared the area around its orbit of objects.” This photograph shows Pluto and its moon, Charon. Pluto’s orbit is surrounded by smaller objects which have not been cleared by its gravitational field. Pluto and the other ‘smaller’ planet-like objects such as Eris and Ceres have now been reclassified as ‘Dwarf Planets’. 7 of 48 © Boardworks Ltd 2008 Data on the Solar System 8 of 48 © Boardworks Ltd 2008 Ideas about the Solar System 9 of 48 © Boardworks Ltd 2008 Exploring space – mission to Mars Our search for answers and clues to the origin of the Solar System and the possibility of life elsewhere led to the development of unmanned space probes. For years, science fiction had brought us stories of Martians – but could they really exist or have existed? On 4th December 1996, NASA launched the ‘Pathfinder’ Discovery Mission to Mars. It cost $150 million and took 7 months to reach Mars. When it had landed, the ‘Sojourner Rover’ buggy tested Mars’s atmosphere, surface and weather, amongst other things. 10 of 48 © Boardworks Ltd 2008 Mission to Mars – tests on Mars The tests carried out by the Rover showed that Mars is much more like the Earth than was expected. Was Mars like the Earth until something catastrophic happened? The tests also showed that the crust of Mars is very similar to continental crust on Earth and that volcanoes had played a part in Mars’s formation. Why did the volcanoes stop? Did the gases they gave out kill any Martian life? 11 of 48 © Boardworks Ltd 2008 Which planet? 12 of 48 © Boardworks Ltd 2008 Solar System quiz 13 of 48 © Boardworks Ltd 2008