ASTRONOMY THE STUDY OF THE UNIVERSE What

ASTRONOMY THE STUDY OF THE UNIVERSE!

What do you think? 1. What is a galaxy? 2. Could this picture be of our own galaxy? Why or why not?

M 100 List types of objects that exist in space. (galaxies, stars…)

CELESTIAL OBJECTS PICTURES, part 1 1. Place cards white-side up and mix. Each team member choose 2 cards. 2. In your notebook, describe observations and inferences about each of your images.

One way to organize… observations Image 1 Image 2 inferences

CELESTIAL OBJECTS PICTURES 3. Share what you wrote with your teammates. 4. As a team, look at the remaining images and share a couple of quick observations and inferences for each.

CELESTIAL OBJECTS PICTURES, part 2 1. As a team, sort or organize all 12 images any way you want. 2. Large-group discussion. 3. Sort by: – size – distance from earth – composition

CELESTIAL OBJECTS PICTURES, part 3 Reading passage on basic objects. (reading directions) Re-sort your cards one more time…

Celestial Objects Celestial: of or relating to the sky

Our solar system includes a star (our sun), planets, and moons, as well as asteroids, meteoroids and comets.

The Moon Earth’s natural satellite A moon is a natural satellite that orbits a planetary body.

Planets A view of our planet Earth from the moon.

A planet is a celestial body… l that orbits the sun l has sufficient mass to assume a spherical shape l has cleared its orbital path

We call our moon “The Moon” but many other planets have moons as well. Mars has two moons: Phobos and Deimos

Jupiter is currently known to have 63 moons. The four largest moons are Io, Callisto, Ganymede and Europa.

Saturn also has many moons. The current count is 60, but that may change in time.

All planets except Mercury and Venus have at least one natural satellite… …for a total of 166 moons.

Stars are celestial bodies of hot gases that radiate energy due to their internal nuclear reactions.

Our sun is the nearest star

Our sun is an average sized star, and much smaller than many other stars

Some stars are red giants and supergiants, which we will learn more about later.

Solar Systems • Solar systems are also celestial objects • Our solar system is not the only one • Many other solar systems are presumed to exist • Some have actually been discovered, one containing five known planets

An artist's concept shows four of the five planets that orbit 55 Cancri, a star much like our own (and located 41 light years away from Earth).

Nebulae (s: nebula) • A nebula is a star “nursery” or an interstellar cloud of dust and gas from which stars are formed Cygnus Loop Cat’s Eye Nebula

Galaxy • A galaxy is group of stars, usually numbering in the billions, that orbit a common mass and travel through the universe as a single unit

We are located in the Milky Way, a spiral galaxy

The spiral Andromeda Galaxy is our nearest galaxy neighbor …yet it is still more than 2 million light years away!

Elliptical is another type of galaxy

There also irregular galaxies

And sometimes galaxies collide…

Black and white pictures. 1. Paste into notebook. 2. Write your own summary notes for each object.

Final questions: What is the difference between: • a galaxy and a solar system? • a planet and a moon?

Old ideas follow.