While we don't know for certain how galaxies formed and took the many shapes that we presently see, we have some ideas about their origins and evolution. Using supercomputers, scientists can look back in time and simulate how a galaxy may have formed in the early universe and grown into what we see today.
Scientists estimate the age of the universe at Because the deeper you look into space, the further you see back in time, we can conclude that galaxies several billions of light-years away formed fairly soon after the big bang.
While most galaxies formed early, data indicates that some galaxies have formed within the past few billion years — relatively recently in cosmic terms. The early universe was filled mainly with hydrogen and helium, with some areas slightly denser than others. Gravity caused the gas in these clouds to collapse and form the first generation of stars.
These first stars rapidly burned out. Gravity continued to collapse the clouds. As other clouds came close to each other, gravity sent them careening into one another and knitted the clouds into larger, spinning packs. As the clouds further collapsed, they became rotating disks, which amassed more gas and dust.
New stars formed, creating extensive spiral arms filled with colonies of stars. Sprinkled along the periphery were globular clusters, along with a halo of gas, dust and dark matter. While Hubble is unable to see the very first galaxies, it can track the development of galaxies over much of cosmic time. The series of Hubble Deep Field images and other deep surveys have uncovered galaxies at many different distances out in the universe, and therefore at many different times in their development.
Farther galaxies, seen earlier in time, have less developed structure. Nearer galaxies, seen later in time, grow to resemble the familiar galaxy shapes we see in the local universe. The Building Blocks of the Universe. On This Page. Types of Galaxies. What Kinds of Galaxies Are There?
This graphic compares illustrations of the three main types of galaxies top with actual photos of galaxies bottom that fit the categories. Credit: A. Feild STScI. Dark Matter. Galaxies, like solar systems, are held together by gravity. In galaxies, the solar systems are separated by vast sections of mostly empty space. The galaxy that contains the Earth and its solar system is called the Milky Way. This galaxy is thought to contain more than billion different stars.
Solar systems orbit around their galaxies just as planets orbit around their suns. It takes the Earth's solar system roughly to million years to complete its orbit. The universe is the largest of these three astronomical concepts.
All things, including galaxies and solar systems, are included within the realm of the universe. Although everything known to man is contained within the universe, scientists believe the universe to be continually expanding. This is thought to be a result of the big bang, the massive explosion of super-condensed matter that created the universe and all things contained within. In contrast, the Universe is all the space that consists of all the galaxy within itself, trillions of stars, black holes.
Earth, our home planet, is a part of the Milkyway galaxy, one solar system and millions of stars, but the milky way, along with all its content, is a part of the Universe that is the ultimate space consisting of all the matter.
A galaxy is a gravitational bond between different stars, gases, dust, and dark matter. The galaxy is more than The universe has more than solar system that has not been even discovered by humans. A galaxy contains trillions of stars within it. There are more than 2 trillion galaxies in the universe that comes in different shapes and sizes. The milky way is a galaxy that consists of a solar system. It is found that all galaxies contain supermassive black holes.
Difference between Galaxy and Solar System. Difference Between Similar Terms and Objects. MLA 8 Ewan, Dart. The word planetary system would more accurately describe a system of planets orbiting around a central star. We are the only planetary that should be called a Solar System because only our star is the Sun Sol.
Additionally, there are planetary systems that are part of a larger star system like Alpha Centauri. In this case, Alpha Centauri is a binary star system two stars that orbit each other. Each of these main stars can have their own planets, even though they orbit each other. Overall I think this is a very helpful article but Solar Systems and Galaxies are best differentiated when you can also include star systems as an in-between example. Name required.
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