The universe is the sum of all matter and
energy that exists, that has ever existed, or that
ever will exist.
There is only ONE universe. You are part of
the universe, as is the Earth and everything on
• In 1929, Edwin Hubble
observed the light being
emitted by other galaxies
was redder than expected.
This shift toward the red end
of the spectrum means the
galaxies were moving away
from us. The farther away
they were the faster they
• This was interpreted to
mean the universe is
How do we measure distance in
• Distance in space is hard to imagine
because space is so vast.
• You need something bigger than miles
and kilometers to measure these large
• Units of measure must have meaning to
the people who use them and be
functional for the purpose they are created
• An astronomical units (AU) equals
150,000,000 km (150 million)—which is
the average distance the Earth is from
• If something is 5 AU away, it means the object is five (5)
times as far away from Earth as the Earth is from the
• Mercury is 0.38 AU; the Earth is 1 AU, and Pluto is 39 AU
from the sun.
•Distances between Galaxies are measured
in light-years (ly).
•A light-year is the distance light travels in
one year—approximately 9.5 trillion km
(9.5 X 1015 km)
•Light travels so fast, it could go around the
Earth seven times in one second.
The Origin of the Universe
• How did the universe begin? This is a
question that scientists are trying to
answer by studying the stars, galaxies,
and planets in our solar system.
• Cosmology is the study of the origin and
evolution of the universe.
• Several theories exists about the origin of
The Big Bang Theory
• According to the Big
Bang Theory, the
universe was created
10 to 20 billion years
ago with a gigantic
explosion that hurled
matter in all
The Big Bang Theory is the dominate theory
about the origin of the universe.
Big Bang Theory
• According to the theory, during the
expansion after the explosion, it cooled the
universe enough to form matter in the form
of neutrons, protons, and electrons. After
a million years, the universe cooled
enough for hydrogen atoms to form. Since
then hydrogen has been the most
abundant element on Earth.
• This is basically an expansion of the Big
• This theory states that during earlier
stages of development, the universe
expanded at a faster rate than it is
• This theory does not propose a
beginning of time.
• It simply states that the universe has
always existed in relatively the same
state it is now and that it will remain
the same forever.
How do we explore space?
• The origin of the
most likely story
puts it in the shop of
•The earliest known illustration of a a Dutch spectacle
Giovanpattista della Porta included maker named Hans
this sketch in a letter written in
Lippersey in 1608.
• The lenses used in
refracting telescopes are
called concave and
convex. Convex (curved
outward) lenses make
things bigger, but blurry.
Concave (curved inward)
lenses make things look
clearer, but small. As you
can guess, a combination
of these two lenses
Refracting telescopes (or
makes things seem
refractors) use lenses to
bigger and clearer.
gather and bend light making
things seem larger.
What happens when you look
through the telescope?
• Imagine we are still outside looking at Venus
with a refracting telescope. An objective, or
large, lens collects light from Venus and sends
it to a smaller, eyepiece lens at the back of the
telescope tube. The eyepiece magnifies the
little image of Venus and directs it at your eye.
Wow, can you see the yellow-white disk? Now
that's some planet!
• Our reflecting telescope
uses mirrors to collect
and magnify light.
Remember that reflecting
developed to solve the
problem of color
distortions caused by
lenses bending light at
different angles. The
Let's say we are still outside looking reflecting telescope's
at Venus, but now we are using a mirror reflects light
reflecting telescope (or reflector). instead of bending it so
there is no color
• With our reflecting telescope, light is
collected by a big concave mirror. The
mirror reflects light to a smaller flat mirror.
This secondary mirror directs the light from
Venus through the eyepiece lens at the
side of the telescope. The eyepiece
magnifies the image. Yep, when we look
through the eyepiece,
• we can see Venus !
• The largest optical telescope in the world is in Hawaii.
It's the 10-meter W. M. Keck telescope. At 4300 meters,
it sits on top of Mount Mauna Kea, an extinct volcano.
Radio telescopes use a large dish to collect radio
waves from space. The dish is the same shape as the
mirror of a reflecting telescope. Radio telescopes are a
valuable tool for astronomers since many objects in the
universe do not produce enough visible light to be picked
up by optical telescopes. One of the world's most
powerful radio telescopes is the Very Large Array (VLA)
in New Mexico. The VLA is made up of 27 linked radio
telescope dishes each 25 meters in diameter.
The Importance of Light
• Most of what we know about the Universe
comes from information that has been
carried to us by light. But we have seen
that visible light is only a small part of the
electromagnetic spectrum. In recent years
the remainder of the electromagnetic
spectrum has revealed extensive
information about our Universe.
• Radio waves have the longest wavelengths in the
electromagnetic spectrum. These waves can be longer
than a football field or as short as a football. Radio
waves do more than just bring music to your radio. They
also carry signals for your television and cellular phones.
• Detect radio signals
emitted by distant
objects. Some of the
oldest, most distant
objects in the solar
system have been
detected by radio
• Radio waves from those
objects were emitted
almost 15 billion years
How do we "see" using Radio
• Objects in space, such as planets and comets, giant
clouds of gas and dust, and stars and galaxies, emit light
at many different wavelengths. Some of the light they
emit has very large wavelengths - sometimes as long as
a mile!. These long waves are in the radio region of the
• Because radio waves are larger than optical waves,
radio telescopes work differently than telescopes that we
use for visible > light (optical telescopes). Radio
telescopes are dishes made out of conducting metal that
reflect radio waves to a focus point. Because the
wavelengths of radio light are so large, a radio telescope
must be physically larger than an optical telescope to be
able to make images of comparable clarity. For example,
• The Parkes radio telescope,
which has a dish 64 meters
wide, cannot give us any
clearer an image than a small
backyard telescope! In order to
make better and more clear (or
higher resolution) radio
images, radio astronomers
often combine several smaller
telescopes, or receiving
dishes, into an array. Together,
the dishes can act as one large
telescope whose size equals Time-lapse view of Parkes radio
the total area occupied by the telescope at night in New South
array. Wales, Australia
The Hubble Telescope
• Named for Edwin
Hubble, the Hubble
Space Telescope now
probes the depths of
the universe from it’s
orbit high above the
Hubble Space Telescope
• Sputnik was the first man-
• Many consider October 4,
1957 to be the beginning of the
Space Age. On this date,
Sputnik — a basketball-sized,
Soviet-made satellite —
orbited our planet. Due to cold-
war tension between the
world’s superpowers — the
United States and the Soviet
Union (now Russia) — the
Sputnik launch fueled the
space race between the two
BIRTH OF A SATELLITE
• Sputnik I's vital statistics
• Launch date: Oct. 4, 1957
• Diameter: 23 inches
• Weight: 183 pounds
• Material: Aluminum alloy
• Life span: About 22 days, ending when transmitter batteries expired
• Name: Translates to "fellow traveler" or "traveling companion" in English
• Function: Gathered data on the atmosphere, emitted beeps, tested radio transmission
• Impact on pop culture: Amid concerns about what Sputnik meant regarding the Soviets'
space and military capabilities, Americans began to riff on the Sputnik theme.
• Bars offered vodka-based Sputnik cocktails; restaurants named sandwiches after the
satellite. There were Sputnik toys and bubble gum, and satellite-shaped ceiling lamps,
earrings and Christmas ornaments.
• Several musicians penned Space Age songs, such as one by Al Barkle with the Tri-Tones
that began with Barkle imitating the satellite's beeping.
• Sources: NASA; Russian space writer Anatoly Zak; After Sputnik: 50 Years of the Spage
Space Race Milestones
• Wide-open spaces: An astronaut
enjoys a spacewalk. Image courtesy
• Intense research and development
ensued over the following decades.
Successes by both nations are marked
by important milestones:
• First person in space — The Russian
astronaut Yuri Gagarin achieved this
on April 12, 1961.
• First person in space — First person
to orbit Earth – American John Glen
orbited Earth on Feb. 20, 1962.
• First person in space — First moon
walk – Neil Armstrong and Buzz Aldrin
were the first people to set foot on the
Moon on July 20, 1969, answering the
challenge of former U.S. President
John F. Kennedy.
On the Horizon
• Currently, both nations maintain active
space programs. Other countries, such
as France, Japan, and China now
have space programs as well. Current
space exploration endeavors include:
• Deployment of reusable spacecraft,
called space shuttles
• International Space Station
• Orbiting space telescope (Hubble
• Unmanned missions to explore Mars
• The future of space exploration may
include bold projects such as a lunar An artist's concept of a Mars
colony and manned missions to Mars.
Many technological challenges must rover - a remotely controlled
be overcome to succeed in these vehicle that traverse the
missions. However, that’s never
stopped us before . . . Martian surface and send data
to scientists on Earth. Image
courtesy of NASA