Astronomy Intro Flashcards

Outline of Celestial Bodies

1. Planets

• Spherical, enough mass and gravitational force to be round

• Orbit a star, typically

• Cleared their orbit of space debris

• Pluto: classified as a dwarf planet due to insufficient mass

• Other Types of Planets:

  • Dwarf Planets

    • Example: MakeMake has no significant atmosphere

  • Exoplanet

    • Example: Arion, 238 light years away

  • Rogue planet: does not orbit a star

2. Moons

• Natural satellites of planets

• Examples: Europa, Luna, Titan

• Planets require a certain amount of gravity to retain moons

• Earth is the first in our solar system to have a moon

3. Stars

• Self-luminous burning balls of fire and gas

• Shine due to continuous nuclear explosions

• Sirius: the brightest star visible from Earth

4. Solar System

• Comprises all celestial bodies under the gravitational influence of our star, the Sun

• Some planetary systems feature multiple stars

5. Galaxy

• Rotates around a gravitational center

• Our solar system resides in a minor spiral arm of the Milky Way

• Nearby galaxy: Andromeda

6. Galaxy Clusters

• The Local Group: A collection of neighboring galaxies

7. Super Cluster

• Laniakea: the supercluster that contains our galaxy

Outline of Important Figures

• AZOPHI: lived in Persia in the 900s AD

  • First person to identify objects beyond our own galaxy

  • Identified the Andromeda Galaxy

  • Recorded his discoveries, sometimes “Father of Astronomy”

• Copernicus

  • Heliocentric solar system

• Galileo Galilei

  • Heliocentric solar system and scientific method

  • Demonstrated how things can be proved

• Tycho Brahe

  • Data collection

  • Accurately observed planets

• Keppler

  • Laws of Planetary Motions

  • Using Tycho’s data

  • Before we knew about gravity

• Lippershey

  • Created Telescopes

• Isaac Newton

  • Laws of Motion

  • Gravitation

• Hubble

  • Early cosmologist

  • Identified that the universe is expanding through math

  • “Extragalactic universe”

• Einstein

  • Cosmology

  • Theory of Relativity

  • Nuclear Fusion/Fission —Stars

  • Space - Time continuum

• Drake

  • Lead the search for intelligent life

  • Mathematician - “Drake Equation”

  • Used factors to calculate the probability of life

• Carl Sagan

  • “Cosmos”

  • Made astronomy accessible

• Stephen Hawking

  • Cosmologist

  • Space time

  • Found an answer to the theory of black holes

• Hypatia

  • Alexandria, Egypt in the late 300s CE

  • leading mathematician, philosopher, and astronomer of her time

• Benjamin Banneker

  • Free black man from the 1700s who wrote an almanac

  • Practically examined astronomical phenomena and their correlation to everyday life

Important Dates/Numbers

• Birth of Earth:

• Birth of the Universe: 7.8 BYA

• Birth of Life on Earth:

• Birth of Human Life:

Units

• Kilometer

• AU: average distance between earth and the sun

• Light year (ly): the distance light travels in a year-63,000 AU

• Parsec: uses earth as an angular reference point-3.26 ly

Branches of Astronomy

• Astrophysics

• Astrobiology

• Cosmology

• Astrogeology