Galactic AddressGalactic Address

An activity to explore your place in An activity to explore your place in the universe.the universe.

Our UniverseOur Universe

Everything that exists anywhere; includes Everything that exists anywhere; includes planets, stars, galaxies, and black holesplanets, stars, galaxies, and black holes

Age- between 10 and 15 billion years oldAge- between 10 and 15 billion years old

In open space, away from stars, the In open space, away from stars, the temperature is -454 degrees F, that is 3 temperature is -454 degrees F, that is 3 degrees away from absolute zero.degrees away from absolute zero.

Origin of the UniverseOrigin of the Universe

Most widely accepted scientific explanation is Most widely accepted scientific explanation is The Big Bang Theory, which continues to be The Big Bang Theory, which continues to be tested with each new discovery about the tested with each new discovery about the universe.universe.

The whole universe was originally packed into a The whole universe was originally packed into a dense sphere of hydrogen, not much larger than dense sphere of hydrogen, not much larger than the sun is today.the sun is today.

About 15 billion years ago the sphere exploded, About 15 billion years ago the sphere exploded, forming an expanding cloud that moved outward, forming an expanding cloud that moved outward, all of the elements of the Periodic Table were all of the elements of the Periodic Table were formed at this time.formed at this time.

Origin of the Universe… continuedOrigin of the Universe… continued

Areas of the cloud eventually condensed Areas of the cloud eventually condensed to form billions of galaxies. to form billions of galaxies.

In 1929, Edwin Hubble found evidence In 1929, Edwin Hubble found evidence showing that the universe is still showing that the universe is still expanding.expanding.

In 1978, Penzias and Wilson found In 1978, Penzias and Wilson found leftover energy from The Big Bang and leftover energy from The Big Bang and won the Nobel Prize in physics.won the Nobel Prize in physics.

GalaxiesGalaxies

A galaxy is a large scale group of stars, A galaxy is a large scale group of stars, gas, dust, and planets bound together by gas, dust, and planets bound together by gravitational attraction.gravitational attraction.

Galaxies contain millions to billions of Galaxies contain millions to billions of stars and there are billions of galaxies in stars and there are billions of galaxies in the universe, millions of light-years apart.the universe, millions of light-years apart.

With a telescope, a galaxy is a fuzzy light With a telescope, a galaxy is a fuzzy light source, while a star is a pinpoint of lightsource, while a star is a pinpoint of light

Galaxies…continuedGalaxies…continued

Three Three mainmain types of galaxies: types of galaxies: Spiral galaxies (75 %)-central lens-shaped Spiral galaxies (75 %)-central lens-shaped

nucleus with spiral arms (containing gas and nucleus with spiral arms (containing gas and dust) that come out from opposite sides of the dust) that come out from opposite sides of the nucleus and trail behind as the galaxy rotates. nucleus and trail behind as the galaxy rotates.

Ex. Milky Way, Andromeda GalaxyEx. Milky Way, Andromeda Galaxy Elliptical galaxies (20%)-nearly spherical to lens-Elliptical galaxies (20%)-nearly spherical to lens-

shaped, with most of the stars close to the shaped, with most of the stars close to the center.center.

Irregular galaxies (5%)-smaller, fainter, and less Irregular galaxies (5%)-smaller, fainter, and less common than the other two types. common than the other two types.

Ex. Magellanic CloudsEx. Magellanic Clouds

Your Galactic AddressYour Galactic Address

It is now time to take a quick tour before It is now time to take a quick tour before you work to find your place in the universe, you work to find your place in the universe, your galactic address…due at the end of your galactic address…due at the end of class period tomorrow.class period tomorrow.

Examine the Milky Way Galaxy at differentExamine the Milky Way Galaxy at different scales. scales.