*The Cosmic Cast of Characters

*Learning Targets

1. I can name the kinds of objects in the universe.

2. I am familiar with the MicroObservatory Image Archive

3. I can make careful observations of images

*Today

*You will soon take your first images of astronomical objects by controlling the MicroObservatory telescopes, which will take images overnight. *First you must think about what type of objects to

choose as your target*You will find out some information about what it

means to be that type of object.*You will sharpen your observing skills while finding

out some interesting facts about these distant objects.

*Your Groups

1. Rodigo, Gautier, Filippo – the bit players

2. Rafaela, João, Daniel, Barbara – the stars

3. Martin, Lucca, Filipe – the nebulae

4. Marco, Lucas, Emiliano – the galaxies

*The MicroObservatory

*Use your device to go to http://mo-www.harvard.edu/MicroObservatory/*Click on “Recent Image Search.” These are the

most recent images taken by MicroObservatory images and where the images you request will be kept.*Now scroll to the top of the page and click on

the Image Archive link. *From here, click on the name of the category of

object given to you (for example “Galaxies”).

*The MicroObservatory

*Locate two images within your category that you would like to examine further.

*On your chart paper write as many detailed observations as possible about each image in the next 10 minutes.

*Make simple observations*What seem to be stars in many of the images

should be described as small round dots in the image. Some round dots appear to be slightly larger than others.

*Describe “what you see” in the image and not “what you think something you see in the image may be.”

*The MicroObservatory

*Read the information about your category of object in the “Notes, Description” column on the “Cosmic Cast of Characters” table. *Prepare two interesting facts from the

table to present to the larger group along with your observations.

*The MicroObservatory

*You have five minutes to write questions that have come up after making many detailed observations.*Each group must write at least one

question to present to the class.

*Debriefing

*Report your observations one group at a time*Report two interesting facts one group at

a time*Share at least one question, either about

your group’s category of objects, or their own.

*Vocabulary

* asteroid: also called minor planets or planetoids, are a class of astronomical objects. The term asteroid is generally used to indicate a diverse group of small rocky celestial bodies in the solar system that orbit around the Sun.

* billion: The cardinal number equal to 109, or a one with nine zeroes after it.

* black hole: A region of space resulting from the collapse of a star with a gravitational pull so strong that from a certain distance, not even light can escape it.

* comet: loose collections of ice, dust, and small rocky particles in the Solar System that orbit the Sun and, when close enough to the Sun, exhibits a visible coma (or atmosphere) and/or a tail — both primarily from the effects of solar radiation upon the comet's nucleus. The nucleus itself measures a few kilometers or tens of kilometers across, and is composed mostly of rock, dust and ice. Comets are nicknamed ‘dirty snowballs.

* galaxy: Any of many very large groups of stars, gas, and dust that constitute the Universe, containing an average of 100 billion (1011) stars and ranging in diameter from 1,500 to 300,000 light-years.

* globular cluster: A system of stars, generally smaller in size than a galaxy, that is more or less globular (like a globe) in shape. light-year: The distance that light travels in one year.

* Milky Way: The galaxy which is the home of our Solar System together with at least 200 billion other stars and their planets.

* million: The number equal to 106, or a one with six zeroes after it.

* The Moon: The natural satellite of Earth.* nebula: A diffuse mass of interstellar

dust or gas, or both. A nebula can be visible as luminous patches or areas of darkness depending on the way the dust and gas absorbs or reflects light given off either inside or outside the cloud.

* The Sun: A star that is the basis of the solar system and that sustains life on Earth, being the source of heat and light.

* supernova: A special event at the end of massive stars’ lives in which the star explodes and shines millions of times brighter than it had during its lifetime. Only stars about 10 times the mass of our sun will die in this way.

* universe: All matter and energy, including the earth, the galaxies, and the contents of intergalactic space, regarded as a whole.