1. The Study of the Universe
EARTH AND SPACE UNIT
Earth and Space Unit
The Study of the Universe

3. Lets study the Structure of the Sun

4. THE SOLAR SYSTEM

5. Measuring Distances in the Solar System
1 AU is the average distance between the Sun and the Earth ( km)
1 AU = km
Jupiter is 780 million km from the Sun, therefore, Jupiter is 5.2 AU from the Sun

7. Asteroids
small celestial objects in the Solar System composed of rocks, minerals and metals
smaller than planets, range in size, have no definite shape
lots located in the asteroid belt between the orbits of Mars and Jupiter (this asteroid belt also separates the inner and outer planets)

8. Satellites
small celestial bodies that orbit a larger one (planet) in a fixed path (example – moons)

9. Meteoroids
celestial objects even smaller than asteroids composed of rock and iron or dust – many are asteroid fragments
can vary in size, from the size of dust particles to the size of buildings
When they are caught in the Earth’s atmosphere, friction causes them to burn up, creating a streak of light across the sky. They are then referred to as Meteors or A SHOOTING STAR!!! (Which occur once every 15 minutes on average).
If the meteor does not burn up completely, small pieces may land on the surface of the Earth, which is referred to as a Meteorite

10. Comets
large chunks of ice, dust and rock that orbit the Sun (the orbit can take a few years to a hundred thousand years) (nicknamed “Dirty Snowballs”)
can be 100m to 40 km in diameter
Short-period comets: originate from just beyond Neptune and orbit the Sun in less than 200 years (for example, Halley’s Comet which takes years to orbit)
Long-period comets: originate from a spherical cloud of debris further than Pluto and orbit the Sun in more than 200 years (for example, Hale-Bopp Comet which takes 2380 years to orbit)
When comets come close to the Sun, the surface sublimates (changes from solid to gas) and the icy nucleus heats up; therefore, gases and dust escape in cloud called a “coma”. Radiation and solar wind from the Sun exert a force on the coma causing a gaseous tail.

11. Planetary Motion
Axial Tilt: the Earth’s axis is tilted 23.5o from the plane of the Earth’s orbit. So the Sun and planets appear to move along a tilted line in the sky.
                                              

12. Rotation –
the turning of an object around its own axis
**The Earth’s rotation is 24 hours
 creates day and night

13. Revolution – the movement of an object around another object (orbit); this movement is not in a perfect circle, but in an elliptical shape
Since the Sun in not directly in the centre of the ellipse, the Earth is actually closer to the Sun in December than it is in June!!!
The Earth revolves around the sun every days
 this is our year

15. Tides The water moves more than the solid Earth does.
There are two high tides and two low tides per day.

16. Solar vs. Lunar Tides
The Sun is more massive but very far away: Solar tide = ½ Lunar tide Solar and Lunar tides may work together or against each other.

17. The Earth’s rotation makes the sky appear to revolve around us.
                                             
                                       

18. Polaris: does not appear to move because it's aligned with the Earth's axis.

19. Classifying Stars
Stars are classified by their size, temperature and brightness.
The sun is neither the largest nor the brightest star but it is the closest to us.

20. Apparent Magnitude
A star’s apparent magnitude is its brightness as seen from Earth.
How does it appear.
The sun appears to be the brightest

21. Absolute Magnitude
A star’s absolute magnitude is the brightness the star would have if it were at a standard distance from Earth.

23. Life Cycle of a Star White Dwarf Black Dwarf Small or Medium Star
Red Giant
1.Nebula/Protostar
Giant or Supergiant Star
Supernova
Black Hole
Neutron Star

24. 1 light year is the distance that light can travel in 1 year, at its speed of 300 000 km/s
1 light year = 9.5x1012 km

25. STAR CLUSTERS
All galaxies contain star clusters which are groups of stars that:
Develop together from the same NEBULA
Are gravitationally bound
Travel together

26. STAR CLUSTERS There are two types of star clusters:
Open star clusters are collections of six to thousands of usually young stars
Globular clusters are ball-shaped collections of thousands to millions of very old stars
There are approximately open star clusters found within the main disc of the Milky Way.

27. They come in different shapes and sizes and are spread across
TYPES OF GALAXIES
Galaxies are collections of millions to hundreds of billions of stars, planets, gas, and dust, measuring up to light years across.
They come in different shapes and sizes and are spread across
the Universe