Space intro lessonAstronomy, Heliocentric, Celestial objects

Astronomy vs. Astrology Astrology AstronomyWhat it is The study of how the

positions of celestial bodies have influence on life events and behavior of people

The study of the origin, movement and behavior of the universe

Scientific basis astrologist Astronomer, cosmologistAbility to predict future

NO YES, based on repeated observations, simulations and theories

Zodiac signs YES NOConstellations 12, first coined by the

Babylonians88

Geocentric vs Heliocentric• Earth at the center • Sun at the center

Geocentric theory• The ancient Greeks (Aristotle

included) noticed moon, sun, and stars revolve in circle around the Earth.

• Observationally based but erroneous

• Heaven is “perfect and unchanging”- idea supported by Catholic Church

• Galileo Galilei (1564-1642) found Jupiter’s moon with his first telescope; backed Corpecnicus’s heliocentric theory

• Clashed with Church; house-confined for the rest of his life

Supermoon on Saturday May 5 2012

http://www.cbc.ca/video/#/Shows/1221254309/ID=2230765368

•Celestial object: any object seen in the sky. E.g. sun, earth, planets, comets

Moon is a celestial object

The Universe = all existing matter and space considered as a whole; the cosmos.

2. How do we know how old the universe is?

Edwin Hubble (1889-1953) used two different methods: A. Measuring speeds and distances of

galaxies and calculate backward to see how long it took for them to reach their current locations

B. Measuring the ages of the oldest star clusters.

1. How old is the universe?13.7 billion years old

Sorting Galaxies activity

• In group of 4, come up with your own categories to classify these galaxies

• What causes the difference in galaxies’ shapes?

Ignore sharp point in pictures; they are stars from our galaxy

Galaxies• A galaxy is a collection of hundreds of billions of stars held

together by gravity•A star = a hot ball of plasma that shines because of nuclear fusion taking place at its core•Earth is part of the Milky Way which is an spiral galaxy•Color of galaxy depends on the age of the stars it contains

Shaped like spheresor ovalOlder & are largest galaxiesFewer young stars than spiral galaxies

Flat & circular with curving armsHave many young stars

Disc-shaped with a bulge in the middle

No particular shape

Properties of galaxies

1. Galaxies contain about 200 billion stars each and usually have a supermassive BLACK HOLE in their centre

2. At least 90% of the mass in the universe may be composed of dark matter

B lack H o le

• Space where gravity is so strong that it can pull anything right into it.

• Masses of stars pulled into black hole increase the size and mass of the original black hole

Dark Matter

• Invisible matter that make up 90% of the matter in the universe. They provide the gravitational force that hold the universe together

• Evidence for presence of dark matter:– Stars around galaxy such as the Milky Way

revolve around the galaxy’s centre at such high speed that they are expect to be flung off

– But they are not. Dark matter explained: http://www.youtube.com/watch?v=nJN2X3NrQAE

Tour of the universe: 3D atlas http://ed.ted.com/lessons/a-3d-atlas-of-the-universe-carter-emmart

Exit activities

Making crossword puzzle for today’s vocab

Making inferences with “How far can you see” article

Summarizing “Hunting Black Hole” article