Transcript Slide 1

Your Place In Space
Created by Dr. A. Davila
The Milky Way galaxy is the spiral galaxy we
call home, as do roughly 100 billion other
stars
The Sun is revolving around the center of the
Galaxy at a speed of half a million miles per
hour, yet it will still take 200 million years for
it to go around once.
The Milky Way has a bulge, a disk, and a halo.
Although all are parts of the same galaxy,
each contains different objects. The halo and
central bulge contain old stars and the disk is
filled with gas, dust, and young stars.
The center of our galaxy is located about
28,000 light-years away, beyond the
constellation Sagittarius (actually just beyond
the border of Sagittarius and Scorpio). So, if
you can locate these two constellations in
the sky, you'll be looking toward the center
of our galaxy!
http://www.windows2universe.org/the_universe/Milkyway.html
http://www.atlasoftheuniverse.com/milkyway.html
http://www.atlasoftheuniverse.com/milkyway.html
There are almost as many
stars between the spiral
arms as in the spiral arms.
The reason why the arms
of spiral galaxies are so
prominant is that the
brightest stars are found
in the spiral arms. Spiral
arms are the major
regions of star formation
in spiral galaxies and this
is where most of the
major nebulae are found.
http://en.wikipedia.org/wiki/Milky_Way
The Solar System is located
in the Milky Way galaxy
halfway out from the
center, on the inner edge of
the Orion–Cygnus Arm. The
Sun orbits around the
center of the galaxy in a
galactic year—once every
225-250 million Earth years.
http://en.wikipedia.org/wiki/File:Milky_Way_Spiral_Arm.svg
http://apod.nasa.gov/apod/ap060828.html
The eight planets now recognized by the International Astronomical Union
(IAU) are: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune
Solar System objects now classified as dwarf planets are: Ceres, Pluto, and Eris.
Planets, by the new IAU definition, must be in orbit around the sun, be nearly
spherical, and must have cleared the neighborhood around their orbits.
A dwarf planet is a category of celestial bodies defined in a resolution passed
by the International Astronomical Union (IAU) on August 24, 2006. Currently,
there are three celestial bodies that have been redefined by the IAU as dwarf
planets:
• UB313 (informally known as Xena, and now formally known as Eris)
• Pluto
http://www.memphisgeology.org/sg_eris.htm
• Ceres
Asteroid Belt
The asteroid belt is found between Mars and Jupiter. Most asteroids are rocky
bodies that orbit the Sun. Scientists estimate the asteroid belt also contains
more than 750,000 asteroids larger than three-fifths of a mile (1 kilometer) in
diameter and millions of smaller ones. Not everything in the main belt is an
asteroid — for instance, comets have recently been discovered there, and
Ceres, once thought of only as an asteroid, is now also considered a dwarf
http://www.space.com/51-asteroids-formation-discovery-and-exploration.html
planet.
A comet is an icy body that releases gas or dust. Scientists think short-period
comets, also known as periodic comets, originate from a disk-shaped band of
icy objects known as the Kuiper belt beyond Neptune's orbit, with gravitational
interactions with the outer planets dragging these bodies inward, where they
become active comets. Long-period comets are thought to come from the
nearly spherical Oort cloud even further out, which get slung inward by the
gravitational pull of passing stars. http://www.space.com/53-comets-formation-discovery-and-exploration.html
http://www.orderoftheplanets.org/kuiper-belt.html
A Hubble Space Telescope image of
Pluto and its Moons, Charon, Hydra
and Nix. Charon is the largest moon
close to Pluto. Hydra is the higher of
the two dots to the right of Pluto. Nix
is the lowest dot.
Pluto orbits beyond the orbit of Neptune (usually). It is
much smaller than any of the official planets and now
classified as a "dwarf planet".
Pluto is a plutoid that is found in the Kuiper Belt.
Therefore, it is just basically a really large asteroid.
http://www.orderoftheplanets.org/kuiper-belt.html
The Kuiper Belt is pronounced as /Ki-per/ and is often called the
Solar system’s final frontier as it is the outermost region of the
solar system. The discovery of its existence was in the year 1992
and was named after a Dutch-American astronomer, Gerard P.
Kuiper who predicted its existence in the early 1950s.
http://solarsystem.nasa.gov/planets/profile.cfm?Object=KBOs
In 1950, Dutch astronomer Jan Oort proposed that certain comets come from a
vast, extremely distant, spherical shell of icy bodies surrounding the solar
system. This giant swarm of objects is now named the Oort Cloud, occupying
space at a distance between 5,000 and 100,000 astronomical units. (One
astronomical unit, or AU, is the mean distance of Earth from the sun: about 150
million km or 93 million miles.) The outer extent of the Oort Cloud is
considered to be the "edge" of our solar system, where the sun's physical and
gravitational influence ends.
http://www.windows2universe.org/earth/earth.html
Earth
Earth, our home planet, is a
beautiful blue and white ball
when seen from space. The
third planet from the Sun, it is
the largest of the inner
planets. Earth is the only
planet known to support life
and to have liquid water at
the surface. Earth has a
substantial atmosphere and
magnetic field, both of which
are critical for sustaining life
on Earth. Earth is the
innermost planet in the solar
system with a natural satellite
– our Moon.
The magnetosphere shields the surface of the Earth from the charged
particles of the solar wind and is generated by electric currents located in
many different parts of the Earth.
http://en.wikipedia.org/wiki/Earth's_magnetic_field
http://science.nasa.gov/science-news/scienceat-nasa/2003/29dec_magneticfield/
Earth's magnetic field
comes from this ocean of
iron, which is an
electrically conducting fluid
in constant motion. Sitting
atop the hot inner core,
the liquid outer core
seethes and roils like water
in a pan on a hot stove.
The outer core also has
"hurricanes"--whirlpools
powered by the Coriolis
forces of Earth's rotation.
These complex motions
generate our planet's
magnetism through a
process called the dynamo
effect.
Earth's magnetic field
comes from this ocean of
iron, which is an
electrically conducting fluid
in constant motion. Sitting
atop the hot inner core,
the liquid outer core
seethes and roils like water
in a pan on a hot stove.
The outer core also has
"hurricanes"--whirlpools
powered by the Coriolis
forces of Earth's rotation.
These complex motions
generate our planet's
magnetism through a
process called the dynamo
effect. absorbed.
The Earth is surrounded by a
blanket of air, which we call the
atmosphere. It reaches near or
over 600 kilometers (372 miles)
from the surface of the Earth, so
we are only able to see what
occurs fairly close to the ground.
Early attempts at studying the
nature of the atmosphere used
clues from the weather, the
beautiful multi-colored sunsets
and sunrises, and the twinkling of
stars. With the use of sensitive
instruments from space, we are
able to get a better view of the
functioning of our atmosphere.
http://www.nasa.gov/audience/forstudents/9-12/features/912_liftoff_atm.html
Life on Earth is supported by the
atmosphere, solar energy, and our
planet's magnetic fields. The
atmosphere absorbs the energy
from the Sun, recycles water and
other chemicals, and works with the
electrical and magnetic forces to
provide a moderate climate. The
atmosphere also protects us from
high-energy radiation and the frigid
vacuum of space.
The envelope of gas surrounding the
Earth changes from the ground up.
Four distinct layers have been
identified using thermal
characteristics (temperature
changes), chemical composition,
movement, and density.
http://www.nasa.gov/audience/forstudents/9-12/features/912_liftoff_atm.html
Past and Future Space Probes
http://solarsystem.nasa.gov/index.cfm
http://www.kidsastronomy.com/index.htm
http://space.jpl.nasa.gov/
http://virtualfieldtrip.jpl.nasa.gov/smmk/top/gates