Throughout the entire universe the different galaxies are scattered. Among all these is the galaxy where our planet Earth is located, known as the Milky Way, but what are galaxies? How was the Milky Way formed? Why is this galaxy called that? These are questions that we have all asked ourselves at some time, but it is the youngest who when they begin to discover the universe have great doubts like these, to which luckily we do have answers.
What are galaxies: definition for kids
We call each of the groupings of stars, stellar dust, planets, particles, nebulae and gases that are distributed throughout outer space and that are held together by gravitational forces. Each of the galaxies is made up of a variable number of stars, of different sizes, ranging from dwarfs to giants. Within a galaxy there are also other small structures, such as nebulae, multiple star systems, star clusters or larger aggregates, known as super clusters.
Depending on their shape, galaxies can be irregular, elliptical, or spiral:
- Irregular galaxies: are those Galaxies that show disturbances due to the gravitational attraction of other nearby or neighboring Galaxies.
- Elliptical galaxies: they are galaxies that have an ellipse shape.
- Spiral Galaxies: These Galaxies have a circular shape and curved arms, wrapped in dust.
Between one galaxy and another there is an intergalactic space formed by gas and with an average density less than one atom per cubic meter.
If you want a simple explanation for children about what the Milky Way is, you can start by telling them that among the various galaxies that exist in the universe is the Milky Way , in which our planet Earth is . All the stars that we see from our planet belong to this galaxy.
The Milky Way is part of a group formed by up to forty galaxies known as the Local Group and a mass of 1012 solar masses is calculated (equivalent to the mass of the sun and 332,950 times the earth’s mass) and an average diameter that reaches up to the 100 thousand light years (a light year is 9.46 x 10 12 km) and it is estimated that the Milky Way has between 200 thousand and 400 thousand stars.
How the Milky Way Formed For Kids
According to international researchers, including scientists from the Instituto de Astrofísica de Canarias (IAC), the Milky Way was formed in two phases , a first fast phase and a second slower one.
From the observations made by the Hubble space telescope , the relative age of 64 globular clusters has been studied, one of the oldest objects present in outer space and which are key to understanding the process of formation and evolution of the Way. Milky. Thus, according to the study, it was determined that in the formation of the galaxy there was a first rapid process of formation of a large part of the stars and globular clusters that make up the Milky Way, and a second slower process of progressive addition of dwarf galaxies, that were included in the Milky Way.
Before this, other research had been carried out to determine how our galaxy formed. However, the quality of the data obtained in this last investigation turned out to be much better than the previous ones and has allowed totally new methodological approaches. These new data and the new analysis methodology have estimated that the globular clusters that surround the galaxy date from about 12.800 million years ago with variations of approximately 800 million years (little for the data analyzed) between them, that is, that most were trained in one process. In addition, more recent clusters were found, which formed in other dwarf galaxies and were incorporated into the Milky Way.
The forming atoms of the stars were hydrogen, helium and others synthesized inside the stars and thrown into space after their death.
Why is it called the Milky Way
It was the Romans who adopted the name of the Milky Way, which means ” milk path “, due to its resemblance to a milky spot in the night sky. The Greeks also called it Kyklo, which means “milky circle ‘”
In Greek mythology, it was Zeus who brought his son Heracles to Hera’s house to feed the goddess when she slept, but Hera didn’t like Heracles, and so he pushed him away, causing some to spill. drops of milk in the night sky.
However, scientifically the bright lights are due to billions of stars in our galaxy seen from the side. This point of light is known as the Milky Way.