ASTRONOMY 330

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ASTRONOMY 330

• Lecture 1

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ASTRONOMY 330

• Instructor Dr. Kevin M. Olson
• E-mail Kevin.Olson_at_gsfc.nasa.gov
• Phone [phone] (Goddard), 5-6853 (UMD)
• Office 1246 CSS
• Office Hours T. Th. 900 AM -
• 1100 AM and by appointment

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Astronomy 330

• Teaching Assistant Ms. Elyse Casper
• E-mail ecasper_at_astro.umd.edu
• Phone 5-1566
• Office 0228 CSS
• Office Hours Wednesdays, 1200 pm - 100 pm

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Astronomy 330

• Class Hours T. Th. 1230 PM to 145 PM
• Location CSS 2400
• Class WEB site http//www.astro.umd.edu/olson/AS
  TR330/

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Astronomy 330

• Text Book
• The Planetary System (3rd edition) by Morrison
  and Owen
• The Lectures Material will be discussed which
  may not appear in the text, especially new
  information
• Other Sources
• http//solarsystem.nasa.gov/index.cfm http//www
  .nasa.gov/vision/universe/solarsystem/index.html

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Astronomy 330 Objectives

• Learn about the Solar System
• What is it ?
• How big is it ?
• What is in it ?
• What are the properties of objects in the solar
  system ?
• How did it form ?
• How do we know what we know ?

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Astronomy 330 Course Outline

• See Syllabus for detailed information about dates
• First 1/3 of Course
• The Sky, Basic Astronomy, Basic Physics, Geology,
  Chemistry, The Sun, The Earth, The Moon
• Second 1/3 of Course
• The Planets
• Last 1/3 of Course
• Finish Planets, Meteorites, Asteroids, Comets,
  Formation of the Solar System, other star systems

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Astronomy 330 Requirements

• 2 Mid Terms Exams (During Class, March 1 and
  April 5) (Each 20)
• Final Exam (Friday, May 20 130 PM - 330 PM)
  (30)
• 10 Homework Assignments (25, lowest thrown out)
• Class Participation (5)
• Optional Assignment (20, lowest of Midterms or
  this assignment thrown out)
• Dont Cheat !

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Astronomy 330 Scientific Notation

• We will use scientific notation frequently in
  this course
• Exponent indicates no. of zeros to follow (e.g.
  103 1000).
• Can also have negative exponents (e.g. 10-3
  .001)

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Astronomy 330 Units of Measurement

• Length
• centimeter(cm),
• kilometer (km) 105 cm,
• astronomical unit (AU) 1.5 x 1013 cm
• Mass
• gram (gm)
• Kilogram (kg) 1000 grams
• Earths Mass 5.973 x 1024 kg
• Suns Mass 1.989 x 1030 kg
• Temperature
• Celsius, 0 degrees freezing, 100 degrees boiling
• Kelvin (K), same as Celsius scale but shifted so
  that zero is at absolute zero (-273 degrees C).

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Astronomy 330 The Sky

• Appears to be a giant dome or as if we inside a
  giant sphereThe Celestial Sphere
• The Stars appear to be fixed to the The Celestial
  Sphere and it rotates about us
• The Sun and Moon appear to move across The
  Celestial Sphere
• The stars are grouped into constellations

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Astronomy 330

• A constellation

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Astronomy 330 Apparent Motions of the Sun, Moon,
Stars

• The Sun, Moon, and the Stars appear to rise in
  the east and set in the west. This motion is
  called their diurnal motion. The entire
  celestial sphere appears to rotate !
• Was once thought that Earth was fixed in space
  and the Sun, Moon, and stars revolved around the
  Earth. Of course we now know this is due to the
  Earth rotating on its axis once in a 24 hour
  period.

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Astronomy 330 Apparent Motions of the Sun and
Moon

• The Sun and Moon also move with respect to the
  fixed background of stars
• The Moon appears to move once around the sky
  (wrt. the stars) in about 28 days. Rises about 1
  hour later each night.
• The Sun appears to move once around the sky (wrt.
  the stars) in about 365 days. Rises about 4 min.
  later wrt. to stars. This is called the Suns
  annual motion.

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Astronomy 330 Moons Phases

• The Moons appearance changes over the course of
  its 28 day cycle.
• The Moon is not visible at the start of its
  cycle New Moon
• The Moon appears to grow or wax after New Moon
  until it reaches is full phase
• Thereafter The Moon appears to shrink or wane.

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Astronomy 330 Moons Phases
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Astronomy 330 The Celestial Sphere

• Horizon Line separating the sky from the earths
  surface
• Zenith Point directly overhead
• Nadir Point opposite zenith
• Meridian Line connecting the Zenith, north
  celestial pole and the south point on the
  horizon. At noon the sun is on the meridian.
• These points and lines are all relative to a
  local observer

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Astronomy 330 The Celestial Sphere
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Astronomy 330 The Celestial Sphere

• The path of the sun across the celestial sphere
  wrt. stars is called the Ecliptic. The ecliptic
  passes through the constellations of the zodiac.
• Celestial Equator Earths Equator projected onto
  celestial sphere
• Celestial Poles Earths poles projected onto the
  celestial sphere. North celestial pole lies near
  the star Polaris.

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Astronomy 330 The Celestial Sphere

• Vernal (Spring) Equinox Point on celestial
  sphere where ecliptic crosses the celestial
  equator and sun is moving from South to North
• Autumnal Equinox Point on the celestial sphere
  where ecliptic crosses the celestial equator and
  the sun is moving from North to South
• Summer Solstice Point on the ecliptic when sun
  reaches is farthest point North
• Winter Solstice Point on the ecliptic when sun
  reaches is farthest point South

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Astronomy 330 The Seasons
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Astronomy 330 The Celestial Sphere

• Right Ascension Lines of latitude projected onto
  celestial sphere measured in units of time (hrs.
  min., sec.) for navigational reasons. Indicates
  distance east of the Vernal Equinox.
• Declination Lines of latitude projected onto
  celestial sphere (measured in degrees North or
  South of Equator).

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Astronomy 330 The Celestial Sphere
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Astronomy 330 Assignment 1

• Read Chapter 1, section 1.1 of Morrison and Owen
• Go to the course WEB site and become familiar
  with it. Important information about the course
  will be posted here !
• http//astro.umd.edu/olson/ASTR330/
• Read the WEB site http//solarsystem.nasa.gov/plan
  ets/profile.cfm?ObjectSolarSysDisplayOverviewLo
  ng
• Fill out the syllabus check sheet. Return it
  next time !

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Astronomy 330 Question for discussion

• How many planets are there ?