Astronomy 101Astronomy 101Section 020Section 020

Lecture 1Lecture 1

John T. McGraw, ProfessorJohn T. McGraw, Professor

Laurel Ladwig, Planetarium Laurel Ladwig, Planetarium ManagerManager

IntroductionIntroduction

The syllabusThe syllabus– The success of this class The success of this class

depends upon depends upon youryour success!success!

– ResponsibilityResponsibility for assignmentsfor assignments to attend classto attend class to prepare interesting, to prepare interesting,

educational lectures and educational lectures and activitiesactivities

to talk to someone when to talk to someone when something isn’t rightsomething isn’t right

A Brief Tour of the UniverseA Brief Tour of the Universe Our tour starts from our Earth, the only planet Our tour starts from our Earth, the only planet

known to harbor life.known to harbor life.

Earth and its moon are almost a “double planet.”Earth and its moon are almost a “double planet.”

Mars is a “rocky,” or terrestrial planet that once had surface water.Mars is a “rocky,” or terrestrial planet that once had surface water.

The sun and planets to scale. Is our multi-planet The sun and planets to scale. Is our multi-planet solar system unique?solar system unique?

Comets and asteroids also orbit the sun.Comets and asteroids also orbit the sun.

The Sun, a normal star, is the heart of our solar The Sun, a normal star, is the heart of our solar system.system.

All of the stars we see at night are in our Milky All of the stars we see at night are in our Milky Way Galaxy.Way Galaxy.

So are all the nebulae that mark star birth and star So are all the nebulae that mark star birth and star death.death.

The Milky Way - self-portrait.The Milky Way - self-portrait.

The Milky Way - detail.The Milky Way - detail. (with apologies to Gary Larson)(with apologies to Gary Larson)

Our tour continues with a visit to the Our tour continues with a visit to the nearest galaxies - here the Large nearest galaxies - here the Large Magellanic Cloud.Magellanic Cloud.

Many galaxies are spirals, similar to our Milky Way.Many galaxies are spirals, similar to our Milky Way.

The most numerous galaxies are ellipticals.The most numerous galaxies are ellipticals.

We’ll visit galaxies in collision - or worse!We’ll visit galaxies in collision - or worse!

Most galaxies tend to cluster - or even Most galaxies tend to cluster - or even supercluster!supercluster!

A quasar (it’s the “star” on the right) - pretty A quasar (it’s the “star” on the right) - pretty boring until you get close. But not too close!boring until you get close. But not too close!

The most distant reaches of the universe are The most distant reaches of the universe are populated by galaxies and quasars.populated by galaxies and quasars.

Galaxies map the structure of the universe.Galaxies map the structure of the universe.

The Earliest Observable Universe – The Earliest Observable Universe – And Structure is PresentAnd Structure is Present

News of the universe!News of the universe!… (make your own “clack, clack, clack” wire service … (make your own “clack, clack, clack” wire service

sounds here)sounds here)

90% of the Universe is missing!90% of the Universe is missing!

We all know that the Universe is We all know that the Universe is expanding – but now it is accelerating!expanding – but now it is accelerating!

Particles from the center of the sun Particles from the center of the sun bombard Earth – but what flavor are those bombard Earth – but what flavor are those particles?particles?

Stay tuned for more – much more!Stay tuned for more – much more!