Date post: | 03-Jan-2016 |
Category: |
Documents |
Upload: | philippa-ferguson |
View: | 217 times |
Download: | 0 times |
Galaxies
When we look out into the night sky what may look like a single star could be an entire galaxy.
Galaxies are huge rotating collections of gas, dust, billions of stars, planets and other celestial objects.
Hubble’s Extreme Deep Field
Galaxies
Our Galactic home is the Milky Way galaxy.
The Milky Way contains more than 200 billion stars, including our Sun.
Earth Zoom to the Milky Way Galaxy
Galaxies
You can see the Milky Way galaxy without any telescopes! All you need is a clear night sky. The Milky Way appears like an arch of light in the night sky.
The Milky Way from Chile
Galaxies
The Milky way is very large –
100 000 light years across.
Our Sun is 30 000 light years
from the center of the galaxy,
which is good because we want
to stay far away from the
supermassive black hole at
the center of our galaxy.
Galaxies
Black holes are thought to be at the center of galaxies. These are extremely dense quantities of matter in space. They have such strong gravitational pulls that nothing – not even light – is fast enough to escape.
10 Mind-Bending Facts About Black
Holes
Galaxies
Black holes are made when a star that is 30 times heavier than the Sun dies and leaves a core that is so massive that it collapses under its own gravity.
Galaxies
Galaxies also contain star clusters.
Star clusters are groups of stars that develop together from the same nebula (a star field – full of gas).
Zoom in on a Star Cluster 5500 light
years away
Galaxies
Elliptical Galaxies are spherical or oval shaped.They are older with very little gas, dust or young stars.Half of the galaxies we see are elliptical.
Galaxies
Spiral Galaxies look like pinwheels – a flattened disk with a central bulge and spiral arms. The core is made of old stars and the arms contain the younger stars. The Milky Way is a barred spiral galaxy (has a central bar).
Galaxies
Quasars are young galaxies with huge black holes in the center. The gas spinning around the black holes glows and is very hot
Galaxies
Irregular galaxies have funny shapes like a blob. They have more gas and dust than other galaxies and contain 100 million – 10 billion stars, irregular are nicknamed “glowing galaxies” because they are small and made up of young stars