Galaxies Quizzes

Galaxies are collections of millions to trillions of stars, star clusters, dust and gas, held together by gravitational forces. They are some of the largest objects in the Universe and can be found in many shapes and sizes. Galaxies come in all sorts of different shapes; spiral galaxies, elliptical galaxies, irregular galaxies and barred spiral galaxies.The Milky Way is a typical example of a barred spiral galaxy. It has a flat disc shape with two arms that wrap around its centre like a pinwheel. These arms contain clouds of interstellar gas and dust along with billions of stars. At the centre is a supermassive black hole that is believed to hold our entire galaxy together by its gravitational pull. Most galaxies are located far away from each other within huge groups called clusters or superclusters which can sometimes contain hundreds or even thousands of individual galaxies. In addition to this, there may be large voids in space where there are few or no galaxies at all for many millions of light years. The study of Galaxies is an incredibly important field as it helps us understand how our Universe formed and evolved over time. By studying the structure and composition of different kinds of Galaxies we can learn more about their age, size, mass and motion which can then tell us about how they were formed and what kind of environment they live in today. For example, astronomers have been able to identify young starbursting regions where new stars form from clouds made up mostly hydrogen gas – these regions tend to exist near the centres most active galactic nuclei (AGN). Through careful observation we can also learn more about dark matter mysterious unknown material thought to make up around 85% percent off all matter in the universe but which doesn’t emit radiation that makes it visible so scientists must use its gravitational effects on nearby objects as an indicator for its presence. In summary, Galaxies are fascinating structures made up billions to trillions on stars held together by gravity forces; they come in many shapes sizes with distinct composition depending on their age/environment; understanding them helps us gain insight into our universe’s formation/evolution plus dark matter making them one very important field within astronomy.