Astronomy 1010-H Planetary Astronomy Fall_2015 Day-2

Astronomy 1010-HFall_2015

Day-2Planetary Astronomy

A Bit About Moi

Why we will be doing stuff other than lecture in class

From How People Learn:“Students enter your lecture hall with preconceptions about how the world works. If their initial understanding is not engaged, they may fail to grasp the new concepts and information that are taught, or they may learn them for the purposes of a test but revert to their preconceptions outside the classroom”How People Learn, National Research Council, National Academy Press, 2000

Active Learning

Active learning is when students take active responsibility for participating in and monitoring of their own learning by engaging in critical reasoning about the ideas presented in the class. In other words: you must do it, you won’t learn it if I just tell it to you

Colored Card Question

The Observations Requirement for this class requires you to:

A. go out on your own and observe the night sky once a week for the entire semester.

B. attend at least one 1st Quarter Observing Night and one Dark Sky Night and write an Observations Report.

C. buy a telescope and observe specific stars and constellations with it.

D. learn the names and locations of 30 stars and 25 constellations in the night sky.

Another Colored Card Question

During the semester there will be:

A. 5 exams plus a final examB. 4 exams plus a final examC. 3 exams but no final examD. 2 exams: a midterm and a final exam

Yet Another Colored Card Question

Texting/social networking is acceptable behavior in class.

A. Strongly disagree.B. Disagree.C. Neutral.D. Agree.E. Strongly agree.

One more Colored Card Question

The homework for this class will be:A. assignments handed out in class

and due the following week.B. assignments posted on the class

D2L website and due in class the following day.

C. assignments in the online SmartWork system plus (possibly) some. assignment handed out in class.

D. None of the above, there is no homework in this class.

IntroductionTo understand the origins of our

planet, we need to understand how our solar system & galaxy formed.

To understand how life formed, we need to understand the chemical evolution of the galaxy and the universe.

This course in a Nutshell, We Have to Explain

How to go from a gaseous nebula …

Through a series of steps …Form a Universe,Form galaxies and stars,Form Planets,Evolve Life,And end up with …

… This

We Live in a Strange Universe

So, Let’s Get Started

What Is A Planet?1) It orbits the central star of the

system.

2) It has to have sufficient mass to self-gravitate to a sphere.

3) It has to have cleared its orbit of “debris”

Classes of Planets1) Terrestrial – Mercury, Venus,

Earth, Mars2) Gas Giants – Jupiter, Saturn3) Ice Giants – Uranus, Neptune4) Ice Dwarfs (Plutoids) – Pluto, Eris,

Sedna, Makemake, …

Two-Minute Essay My name is…

What is the largest thing that exists? Numerical answer, include units!

What is the smallest thing that exists? Numerical answer, include units!

Powers of 10

Zoomable

The Universe is Vast!Scale:The Earth is small,Orbits a medium

star,In a small groupOn the edge of the Virgo

Supercluster (a smallish

cluster)

Useful Information for Next LabBasic Coordinates and Seasons Lab

ClassAction Web Site (Link from apsu.edu/astronomy)

Print the instructions BEFORE you come to class!

Sexagesimal NotationWhat is sexagesimal notation?

Expressing a coordinate as DD:MM:SS or HH:MM:SS

As opposed to decimal degrees: DD.ddddd

Used for coordinates on Earth and in space.Useful for map reading (after your GPS

dies).

Sexagesimal NotationConvert from sexigesimal to decimal degrees:

87:20:30.426 W longitudeThe proper way:87° + (20m/60m/°) + (30.426s/3600s/°)= 87 + 0.3333 + 0.00845= 87°.34175 W

Sexagesimal NotationConvert from decimal degrees to

sexigesimal :

36°.56174 N latitude36° + (0.56174° x 60m/°) = 33m.704133m + (0.7041m x 60s/m) = 42s.2460

= 36:33:42.2460 N latitude

Two-Minute Essay My name is…

What is the largest thing that exists? Numerical answer, include units!

What is the smallest thing that exists? Numerical answer, include units!

… which is one of billions of galaxies …

NASA/ESA/S. Beckwith (STScI) and the HUDF

Team

in a universe that is 13.7 billion years old.

Solar System

Longer DistancesThe Closest Star

Our Galaxy

The Closest Big Galaxy

The Universe

Measuring DistancesThe universe is vast.We need to handle great distances and

long times.We can do this through the travel time of

light.Light travels 300,000 km every second.We often use times to denote distances.

For example, we may say a friend’s house is two hours away.

Astronomy is a time machine!

Measuring DistancesClose to home (Solar System) we will

use:Kilometers (for distance to Moon, sizes)Astronomical Units (AU) or light-

minutes – distance to most planetslight-hours for distances to the farther

planets

Lecture-Tutorial:Sun Size – p. 113

Work with a partnerRead the instructions and questions carefullyTalk to each other and discuss your answers

with each anotherCome to a consensus answer you both agree

onIf you get stuck or are not sure of your

answer ask another groupIf you get really stuck or don’t understand

what the Lecture Tutorial is asking as one of us for help

Colored Card Question:Where Are We?

The Sun is part of:

A.The Solar System.B.The Milky Way Galaxy.C.The universe.D.All the above.

Cute and ScienceCute and Science

Science vs. AuthorityScience is subversive.Old ideas can be falsified and rejected.New ideas must be supported by

evidence.Authority often works by suppressing

inquiry.Scientific authority can be overthrown

by new or better evidence.Nature is the arbiter of science. It

decides what ideas are good or bad.

Science Is CreativeScience is one of many creative

human activities.It has its own rules for deciding

what is right and wrong.It is an important way for achieving

knowledge and insight.There are also other valuable ways

to achieve understanding.

Science Is an ExplorationIdeas can be tested by observation.Telescopes, satellites, etc. extend our

observations to the very large or very distant.

Space exploration has expanded our view of planets and the Solar System.

Astronomy is the science of the exploration of the Universe and the matter and energy it contains.

Science Is a ProcessScience is a method for learning about

nature.The scientific method works like this:

Ideas are tested against nature.Tests come from observation or calculation.

The tests falsify some ideas and support others.

All scientific knowledge is provisional.

A Scientific Result: We Are Stardust

Our bodies contain many types of atoms.Except for the hydrogen in water (H2O),

all the atoms were made in stars.Stars generate energy by making

heavier elements out of light ones.They eject the material into space.New stars and planets (and humans)

form out of the ejected material.

Hallmarks of Modern Science1. Modern science seeks explanations for

observed phenomena that rely solely on natural causes.

2. Science progresses through the creation and testing of models of nature that explain the observations as simply as possible.

3. A scientific model must make testable predictions about natural phenomena that would force us to revise or abandon the model if the predictions do not agree with observations.

Modern ScienceThe Scientific

Method.ObservationsQuestionHypothesisPredictionTestRevise/More Predictions