Milky Way: Does It Have A Habitable Zone?
Measuring approximately 180,000 light years across, the Milky Way is enormous and contains 100 to 400 billion stars in its periphery. However, what regions make up the habitable or inhabitable zones in our galaxy, and is there a habitable zone at all?
According to a source, the Milky Way has zones that are really inhabitable, and three such areas have been identified. Near the center of our galaxy, where the star density is greater, the combined radiation of all the stars present would make it highly unlikely for life to form. Closer to the galactic core is also inhabitable because the Oort Cloud, which is a huge cloud of comets that surrounds the Sun, can start on a collision course, leading to massive disruptions. The Milky Way's spiral arms are another inhabitable zone because star formation is a more common occurrence here due to increased density of the galaxy. Newly evolving stars pose the risk of blasting out dangerous radiation.
Our planet is located around 27,000 light-years away from the Milky Way's center and is a whopping ten of thousands light years away from its outer boundary. The location of Earth also implies that does not cross with the spiral arms, and at the same time, the planet is close enough to have profited from the solar system's action when it gathered the elements needed for life.
The Universe's earliest stars comprised only of helium, hydrogen and slight traces of other elements that remained from the Big Bang. It was only when the hugest stars exploded as supernovae that they spread heavier elements, like carbon, oxygen, gold and iron into the surrounding areas. Many generations of stars sprinkled the solar nebula with their heavy elements, setting the stage for further evolution by providing the necessary raw materials. Therefore, as per studies, if the solar system was located further out, it wouldn't have been able to work on the benefits left by the numerous generations of dead stars.
So, where or what is the galactic habitable zone? According to astrobiologists, the habitable zone of the galaxy could begin right outside the galactic bulge, i.e. around 13,000 light years from the Milky Way's center, and ends somewhere around 33,000 light years away from its center. Therefore, the approximations imply that the Earth just about makes the cut by being located 27,000 light-years from the center.
At the moment, the theory has not been accepted by all astronomers, and more data and research are needed as evidence. However, for now, earthlings are still the lucky ones as, "it turns out you were super duper extra lucky. Right universe, right lineage, right solar system, right location in the Milky Way. You already won the greatest lottery in existence," a report stated.