The Milky Way Galaxy - Our Home
The Milky Way galaxy is the
spiral galaxy we call home, as do roughly 100 billion other
stars. It looks very much like other spiral galaxies when viewed from
above. There are spiral arms and a bright central part. The Sun is
far from the center of the Galaxy, halfway to the edge of the Galaxy
along the Orion spiral arm.
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. Do you feel like you are moving at that speed
through space? If you did, you would certainly need a seat belt! When
we run, we feel the wind on our bodies because there are molecules
which make up the air that push against our bodies. But there are
very few molecules in the space between the stars. So there is
nothing to push against our planet so that we "feel" like we are
rushing around at half a million miles per hour.
A galaxy like the Milky Way as viewed from the top, and the
actual Milky Way as viewed in the infrared
Click on top image for diagram (276K JPEG)
Click on bottom image for diagram (204K JPEG)
European Southern Observatory & NASA COBE Project
Like other spiral galaxies, 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. Our Sun is itself
a fairly young star at only 5 billion years old. The Milky Way galaxy
is at least 5 billion years older than that.
Questions and answers about the Milky Way
A Matter of Scale - interactive showing the sizes of things, from very tiny to huge - from NSF
Shop Windows to the Universe Science Store!
The Summer 2010 issue of The Earth Scientist
, available in our online store
, includes articles on rivers and snow, classroom planetariums, satellites and oceanography, hands-on astronomy, and global warming.
You might also be interested in:
Spiral galaxies may remind you of a pinwheel. They are rotating disks of mostly hydrogen gas, dust and stars. Through a telescope or binoculars, the bright nucleus of the galaxy may be visible but the...more
NASA launched its newest satellite on June 24, 1999 from Cape Canaveral.The Far Ultraviolet Spectroscopic Explorer (FUSE) began its mission aboard the new Delta II rocket, which helped get the satellite...more
According to Navajo mythology, the Milky Way was created by the mischievous behavior of the god, Coyote. When the world was created, the Holy People gathered around Black God to place the stars in the...more
During the early 1900's, which is not very long ago, astronomers were unaware that there were other galaxies outside our own Milky Way Galaxy. When they saw a small fuzzy patch in the sky through their...more
What is light pollution? Simply put, light pollution is the unwanted illumination of the night sky created by human activity. Light pollution is sometimes said to be an undesirable byproduct of our industrialized...more
For a long time, scientists have wondered if there are other systems of planets like our own in our galaxy. Recently a team of astronomers discovered a solar system almost 5,000 light years away that has...more
In the 1960's, the United States launched some satellites to look for very high energy light, called Gamma Rays. Gamma Rays are produced whenever a nuclear bomb explodes. The satellites found many bursts...more