Different Types of Galaxies
Galaxies come in different shapes and sizes. Usually they look like fried eggs; a
flat circle with a bulge in the middle. If we were able to look at a galaxy from
above, it would appear as a bright ball with arms spiralling out of it, spinning.
The Andromeda Galaxy
The Andromeda galaxy is the closest galaxy to our own, the
Milky Way. It is also a similar shape to the
Milky Way, although it is four times bigger! It can be visible from
Earth on a clear night provided there are no lights nearby illuminating the sky and the
Moon is a New Moon and therefore not visible.
Two Galaxies Colliding
In this picture, we can see two galaxies colliding.
The smaller galaxy would be similar to the Milky Way
in size if the bigger galaxy was the Andromeda Galaxy. It is likely that
the smaller galaxy is being attracted to the larger galaxy by the combined
gravitational pull of the many billions of stars in its centre.
A Pinwheel Galaxy
This galaxy is another Spiral Galaxy. We can see
that it spins in an anticlockwise direction, showing us these spiral tails
spinning around like a Catherine Wheel. These tails are very long and will
take millions of years to return to the same spot that they are in now.
This galaxy is known as the Sombrero Galaxy because
it resembles a Mexican hat. It has a large Galactic Centre and the stars in it
appear to spin around it more like the rings of
Saturn than the stars in a Spiral Galaxy.