The Universe

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The Universe
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Cosmology

• the branch of astronomy that deals with the
  origin, large-scale properties, and the evolution
  of the observable universe

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The Universe

• in astronomy, the sum total of all things which
  can be directly observed or whose physical
  effects on other things can be detected
• in simpler terms, space and all the matter and
  energy in it
• major components
• galaxies
• solar systems
• planets

Can you think of something in the universe that
cannot be seen, but its effects on other things
can be detected?
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Big Bang Theory

• the primeval explosion of space, time, matter and
  energy that most astronomers think gave rise to
  the universe as we see it today.
• occurred about 13.7 billion years ago
• thought to have expanded within a second from
  something the size of a spec of dust to the size
  of our solar system

Misconception Alert Describing this theory
as the Big Bang is a misnomer because there
really was not an explosion, just a release of
energy
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Edwin Hubble

• determined that other galaxies exist, besides the
  Milky Way
• observed that galaxies were moving away from each
  other
• Hubble Law the farther away a galaxy is, the
  faster it is moving away from us supports the
  Big Bang Theory

Image taken from http//apod.nasa.gov/apod/ap9602
17.html
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Arno Penzias Robert Wilson

• accidentally detected faint radiation on a radio
  telescope in 1965
• determined that the radiation was leftover
  thermal energy from the big bang

Image taken from http//www.einstein-online.info
/en/elementary/cosmology/early_universe/index.html

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Galaxy

• a large assemblage of stars (and often gas and
  dust), typically containing millions to hundreds
  of billions of member stars
• Star - a large hot ball of gas which generates
  energy in its core by nuclear reactions
• around 100 billion in the universe
• held together by the gravitational attraction of
  all its member stars on one another
• formed around 200 million years after the Big
  Bang
• most large ones seem to have super-massive black
  holes at their centers
• sometimes contain very bright centers called
  quasars
• 3 major types
• Spiral
• Elliptical
• Irregular

What is the name of the galaxy we reside in?
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3 Types of Galaxies
Elliptical shaped like spheres or eggs have
almost no dust or gas between stars contain old
stars
Irregular faint galaxies without a definite
shape smaller than the other types of galaxies
contain fewer stars
Spiral have arms of stars, gas , and dust that
curve away from the center of the galaxy in a
spiral pattern Ex. Milky Way
The process of galaxies colliding to create a
larger galaxy is known as galactic cannibalism.
Images taken from http//school.discoveryeducatio
n.com/schooladventures/universe/galaxytour/toknow.
html
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Constellation

• a group of stars that form a pattern in the sky
• stars of a constellation are often far apart from
  each other, but they appear grouped together when
  viewed from Earth
• one of 88 sectors into which astronomers divide
  the sphere of the sky named after a traditional
  constellation in that sector
• patterns of constellations are dynamic
  therefore, the constellations of 100,000 years
  ago are quite different from todays
• a part of a constellation that forms its own
  pattern in the sky is known as an asterism (ex.
  The Big Dipper)

Why is it not possible to see all constellations
at once?
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Solar System

• the sun and all things orbiting around it,
  including the eight major planets, their
  satellites, and all the smaller pieces such as
  asteroids and comets
• formed around 4.6 billion years ago

What is incorrect or misleading about this
visual?
Image taken from http//asm.arc.nasa.gov/Gallery
/images/generic/LG_Capableofeverything.jpg
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Planet

• derived from a Greek word that means wanderer
• a major object which orbits around a star
• in our solar system, there are eight such objects
  which are traditionally called planets

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Asteroids

• small, solid, rocky bodies that orbit close to
  the Sun
• most found between the orbits of Mars and Jupiter
  in the Asteroid Belt
• thought to be leftover material from the
  formation of the solar system
• range in size from 1000 km or 621 miles (Ceres)
  to the size of pebbles

Image taken from http//www.windows.ucar.edu/tou
r/link/our_solar_system/asteroids.html
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Meteoroid, Meteor, Meteorite
Meteoroid (asteroid)

• Meteoroid solid debris from space (asteroids)
  that are moving towards Earth
• Meteor
• a brief streak of light produced by a small
  particle entering Earths atmosphere at high
  speed
• often referred to as shooting stars or falling
  stars
• travel at speeds between 11-72 kilometers per
  second (6.8 44.7 miles per second)
• Meteorite a small object from outer space that
  passes through Earths atmosphere and reaches the
  surface
• Freehold Meteorite - MSNBC
• Freehold Meteorite - USA-Today

Meteor
Meteorite
The Earth animation is not rotating in the
correct direction it should be rotating from
west to east
What causes a meteor shower to occur?
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Comet

• a small body of ice and dust (dirty snowball)
  that orbits the Sun
• contain a head (coma) followed by a tail(s) of
  gas and dust
• the tail always points away from the sun and can
  be millions of kilometers long (but the amount of
  matter it contains can be very small)

Image taken from http//www.space.com/bestimg/in
dex.php?guid45b0fd31f065dcatbestcomet
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Satellite

• an object that orbits a more massive object (i.e.
  moons)
• probes we launch into orbit around the Earth are
  called artificial satellites

The Earth animation is not rotating in the
correct direction it should be rotating from
west to east
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Telescope

• a device that gathers electromagnetic radiation
• Types
• Visible, infrared, ultraviolet pick up visible,
  infrared, and ultraviolet waves
• Reflecting - use mirrors that reflect the image
  being viewed
• Refracting using lenses, gathers light and
  focuses it near the opposite end of the tube
  works like a magnifying glass
• Radio - pick up radio waves emitted from space
  not effected by variables like weather or clouds

Internet Telescope
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Hubble Space Telescope

• a reflecting telescope that was placed into orbit
  in 1990
• sends images and measurements back to Earth
  electronically

Image taken from http//hubblesite.org/gallery/
What is one of the main benefits of having the
Hubble Space Telescope in orbit, as opposed to
it being here on Earth?
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Astronomical Unit (AU)

• unit of distance equal to the average spacing
  between the Earth and the Sun
• equal to about 150 million kilometers (93 million
  miles)
• light takes about eight minutes to cover this
  distance

The Earth animation is not rotating in the
correct direction it should be rotating from
west to east
150 million km (93 million mi.)
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Light Year

• the distance that light travels in one year in a
  vacuum, which is about 9.5 trillion kilometers (6
  trillion miles)
• The Milky Way Galaxy is about 100,000 light years
  in diameter
• the speed at which light travels this distance is
  about 300,000 km/sec (186,000 mi/sec)

The second closest star to the Earth is a little
over four light years away. How far away (in
miles) is the star?
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Parsec

• unit of distance equal to about 3.26 light years
  (or 206,265 AU)

If one parsec equals 206, 265 AU, how many miles
is it equal to?
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Parallax

• the apparent shift in position of an object when
  viewed from different locations
• used by astronomers to measure distance

Put your pointer finger in front of your face and
begin opening and closing your eyes in an
alternating manner. What do you notice about the
your fingers position?
Parallax Simulation Parallax Simulation
1 Parallax Simulation - 2 Find the Distance to HT
Cas Using Parallax