Galaxies are sprawling space systems formatted through a massive amount of gas, dust and countless stars as well as solar systems. The number of galaxies is numerous. The recognizable universe alone may include are over 100 billion. Some of these as similar to our Milky Way galaxy other are different.
Galaxies with above 100 billion stars are taken as large galaxies, our own galaxy comes into this category where the sun is just one of 100 billion stars
Categories of galaxies
Spiral galaxies: these galaxies include a huge number of stars, planets, a large amount of dust and gas which circle around the galactic center regularly, such as Milky Way galaxy. The spinning motion at a speed of hundreds of Km/Sec. might be the reason behind the disk to take on a different spiral shape such as cosmic pinwheel. Some galaxies in this categories, acquire even more controversial looks which earn descriptive names for them, like sombrero galaxies.
Elliptical galaxies: it mostly contains older stars with up to trillion of age, and a little dust as well as the interstellar matters. These are basically round stretch longer along one axis than other. They are close to circular or lengthen that they appear on a cigarlike appearance.
Irregular galaxies: which are not spiral or elliptical, appear misshapen and lack of different form, i.e. due to they are closely influenced by the gravitational force of other galaxies.
Interesting Facts related to Milky Way Galaxy
The Milky Way galaxy contains our Solar System, “Milky Way” is translation Latin word lacteal. The Milky Way from earth appears as a band due to its disk-shaped structure if viewed from within. At the center of the great Milky Way Galaxy.
Astronomers believe that the universe was formed through the explosion called the Big Bang. And the Milky Way Galaxy was formed sooner after the universe through the dark matter, cloud of gas which pulled in surrounding objects by gravity.
Some of the interesting findings of our Milky Way Galaxies are listed below:
One of the ancient Greek philosopher Democritus was the first person to suggest the existence of Milky Way that made of stars in about 460 to 370 BC. Later in 1620, Galileo identified the Milky Way’s band of light as individual stars. However, an American astronomer, Mr. Edwin Hubble is said to have found the right span and shape of this galaxy also discovered the presence of other galaxies outside of the Milky Way.
It is said to belong at least 100,000 light years across, shaped as a large spiral which rotates once in a 200 million years. The estimation of stars in this galaxy ranges from 100 billion to 400 billion.
The rotational Galactic center of Milky Way contains a supermassive black hole that’s taking most of the nearer things to its surface due to its powerful gravity force, whose size is expanding regularly.
There are different cultural aspects of Milky Way, in China, it is called “The Silver River”. In ancient Chinese myth, the rivers are set in the heavens by the gods purposed to separate a weaver who manufactured clothes and herdsman who loved her. The Romans called this galaxy as the Road which reminded them of milk. In Sanskrit, it is known as the “Ganesh of the heavens” or Akash Ganga.
The Milky Way is whirling speedily, rotate the stars at the speed of around 100 million Km/hr. It takes around 200 million years to travel around the galaxy by sun, i.e. as a journey of almost 100,000 light years.
Our galaxy has a diameter of around 9.5 x 1017 Km. i.e. and if our solar system was a United States (U.S.) quarter, the sun would be microscopic speck of dust and Milky Way would be as a sized the US
The average time to complete a rotation by a galaxy to itself is above 250 million years, our sun has traveled the Milky Way Galaxy for around 16 times since it was formed, and expected to circle 16 more years till its destruction.
This galaxy has a halo of dark matter which generates more than 90% of its mass. That means we are able to see only 10% of the mass of our galaxy even by the telescope. The scientists say, the Milky Way itself has small galaxy within that has named as the Sagittarius Dwarf Galaxy.
Space Scientist or Astronomers predict that seven new stars in Milky Way Galaxy generated every year. Which form inside the large number of gas, dust, and clouds.
If Earth orbited our Sun at the speed of the stars, which are close to the center of the Milky Way, the earth would travel around the sun just in three days instead of 365.