Solar system _ sun_ planets_ satellites.pptx

About space

1. Space The universe contains around 100 billion galaxies Each galaxy can contain hundreds of billions of stars like our sun Planets can orbit stars and that is what makes our solar system The Hubble Telescope caught this image by looking at a single pixel of sky

2. Our Solar System Our Solar System contains: A Star: The Sun Planets: Which go around the Sun Satellites: Which go around planets Smaller objects: Such as asteroids and comets The Solar System is often shown as being flat like this but it is really 3D

3. Order of the Planets Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune You can remember this using the sentence: M y V ery E asy M ethod J ust S peeds U p N aming

4. Mnemonic Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune M y V ery E asy M ethod J ust S peeds U p N aming Create your own mnemonic to remember the order of the planets M V E M J S U N

5. Add a diagram of the order of the planets to your mnemonic

6. Dwarf Planets Until 2006 we used to say Pluto was a planet and that we had nine planets in the solar system This was done because we were discovering too many objects the size of Pluto We now call these Dwarf Planets Our Moon is bigger than Pluto but can’t be a planet because it orbits Earth not the sun

7. Asteroids Our solar system has two main asteroid fields Asteroids are huge lumps of rock that aren’t big enough to be planets . They often contain metal ore

8. Comets Comets are collections of ice , dust and small rocky particles They tend to have very long highly elliptical orbits Halley’s comet is one of the most famous and is visible in the sky every 76 years

9. Heliocentric Model We used to believe that the Earth was at the centre of the universe and everything orbited us Space exploration and use of telescopes means that we now understand that the Earth orbits the Sun Heliocentric is named after the Greek god Helios which means Sun

10. Night and Day The Earth is constantly rotating on a tilted axis This causes night and day The Earth also orbits the Sun This causes seasons From space you can see a definite line between night and day as the Earth rotates

11. The Earth is on a tilted axis Every 24 hours the Earth turns around this axis once

12. DAY NIGHT It is always day on the side of the Earth that faces the Sun

13. 9am 12 noon 3pm The Sun appears to move across the sky but this is really the Earth rotating The position of the sun also affects our shadows E W

14. Time Zones If it was 4:00 in London what time would it be in… We belong to the GMT time zone which stands for Greenwich Meridian Time Place GMT Time Casablanca +1 Pretoria +2 Antanarivo +3 Philippines +8 05:00 06:00 07:00 12:00

15. Daylight Savings Time Daylight savings time is when we move the clock forwards by one hour in spring take it back off in autumn. This is so that it is lighter during the evenings so lights don’t have to be used and people can shop. Not every country uses daylight savings time . It is mostly used in America and Europe.

16. Daylight Savings Time Task: Read the article and write a response back to Chris Hill explaining why he is wrong. Include: An explanation as to how he is mistaken. What daylight savings time is. Why it is used.

17. Seasons Seasons are caused by the Earths tilted axis and its position in orbit around the Sun The seasons in the northern hemisphere are always the opposite of those in the southern hemisphere Everything above the equator is in the northern hemisphere everything below in the southern hemisphere

18. Why do we get Seasons? Seasons happen due to Earth being on a tilted axis When the northern hemisphere is pointed towards the Sun it is Summer in the UK When the southern hemisphere is pointed towards the Sun it is Winter Globes also rotate on a tilted axis to represent how the real planet does

19. Sunrise and Sunset The tilted axis of the Earth makes the Sun appear lower in the sky during Winter

20. The Moon The Moon is Earths natural satellite A satellite is something that orbits a larger body It is a natural satellite because it is not man made Scientists believe the moon was once part of Earth but was blasted off in a collision as the Earth formed

21. The Moon The Moon is held in orbit around the Earth by Earth’s Gravity It does not produce its own light like stars do, it just reflects the suns rays This is why we can see it at night The moon can sometimes appear to be orange. This is caused by our atmosphere scattering the light it reflects

22. Phases of the Moon It takes the Moon 28 days to orbit the Earth Over these 28 days the Moon appears to change shape This is because only half of the Moon is facing the Sun and we can’t see the dark side This shows how the moon appeared over the course of a month

23. Eclipses A solar eclipse happens when the Moon passes between the Sun and the Earth. This casts a shadow over the Earth A lunar eclipse happens when the Earth passes between the Sun and the Moon. This casts a shadow over the Moon. Solar eclipses are very rare however lunar eclipses happen most years

24. Eclipses Solar Eclipse Lunar Eclipse

25. Stars The nearest star to us is the sun We sometimes think of stars as being very tiny, especially when we look up at the night sky This is only because they are very far away z

26. Galaxies A galaxy is a collection of hundreds of billions of stars orbiting around a supermassive black hole at the centre Our galaxy is called the Milky Way and contains around 300 billion stars just like the Sun Our Galaxy will one day collide with its closest neighbour Andromeda

27. Gravity Gravity is an attractive force that affects anything with mass Even people attract other objects with gravity but our mass isn’t large enough for the force to be very strong Isaac Newton discovered gravity when an apple fell on his head

28. Mass Mass is the amount of matter (or stuff ) an object contains Mass is measured in grams ( g ) An objects mass is the same wherever it is An Elephant contains more matter than a mouse so has more mass

29. GRAVITY Gravity pulls down to the centre of the earth no matter where you stand on it

30. Mass and Gravity The effects of gravity only become significant when objects get to the mass of a moon or planet The more mass an object has the stronger its gravity will be The sun has the most mass out of anything in our solar system so it has the most gravity

31. Mass and Gravity Gravity and Mass are directly proportional This means as you increase one the other increases at the same rate If you double the mass of an object you double its gravity

32. Distance and Gravity Gravity gets weaker the further away you get from an object Every time you double the distance from an object the effect weakens by four times You don’t have to be far from earth to appear weightless

33. F F/4 F/16 F = Force of Gravity

34. Gravity Summary Gravity is changed by two things: Mass : When we double the mass we double the effects of gravity Distance : When we double the distance we divide the effects of gravity by four

35. Orbits Orbiting is when an object travels around another due to gravity Objects will only orbit things with a higher gravitational force than themselves E.g. The Moon orbits the Earth and the Earth orbits the Sun Orbits are usually circular but not always They can also be elliptical

36. Planet Orbits The further away a planet is from the sun the longer it takes for it to orbit it The time for a planet to orbit a star is called a year A year on Earth is longer than a year on Mercury The length of a year on Earth is 365 days On Neptune a year is 60048 days long

37. Planet Orbits The further away from the Sun a planet is the slower it travels

38. Weight Weight is a force caused by gravity Weight is the gravitational force between objects Because weight is a force it is measured in Newtons ( N ) People usually use the word weight wrong and get it confused with mass

39. Weight, Mass and Gravity Wherever you are in the universe your mass will be the same But depending on how strong the gravity is you can weigh different amounts Because gravity is weaker on the moon astronauts weigh very little

40. 3000N 300Kg Mass Weight On earth you wouldn’t be able to lift a safe because it would weigh too much

41. 500N 300Kg Mass Weight On the moon the safe would have the same mass but its weight would be lower

42. 500N 300Kg Mass Weight Because it weighs less you would be able to pick up the safe

43. Gravity Calculations Earths gravitational field strength is 10N/Kg If a man had a mass of 80kg then you could enter those numbers into the formula to calculate his weight Weight = 10 x 80 = 800N G M W x W: Weight M: Mass G: Gravitational Field Strength Weight (N) = Mass (kg) x Gravitational Field Strength (N/kg)

44. Satellites Artificial Satellites are man-made objects that are launched in to space and orbit Earth They are held in orbit by Earth’s gravity and their own velocity Over time their orbit will decay and they can fall back to Earth This shows all the satellites and space debris in low Earth orbit

45. Uses for Satellites Satellites have many uses including : Communications Global Positioning System Predicting Weather Scientific surveys of the Earth's surface Map making Spying TV Satellites use solar panels as a renewable way to power their systems

46. Space Telescopes A telescope in space has no light pollution or interference from the atmosphere They are incredibly expensive though The Hubble Space Telescope was launched in 1994 When the Hubble was first launched it didn’t work It needed ‘spectacles’ due to a mistake

47. Space Probes Space probes are used to explore our solar system and beyond Because they are unmanned they can be made quite small and they don’t need to carry food or oxygen This makes them a lot cheaper than manned space flights Voyager 1 was launched in 1977 and is very close to entering interstellar space Every year it travels the same distance as there is between the Earth and Sun

48. Manned Space Flights The space race between America and Russia culminated in Neil Armstrong setting foot on the Moon in 1969 Humans have yet to travel further due to the time, money and resources it would take Laika the dog was the first living thing to orbit the Earth and also to die in orbit